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Author: Wholesale Solar

Wholesale Solar of Mt. Shasta, CA, is an employee-owned company specializing in the design and distribution of custom solar systems and components. Since launching in 2002, Wholesale Solar has helped thousands of DIY homeowners achieve lower power bills and energy independence. Learn more at WholesaleSolar.com.
Expanding Your Off-Grid Solar System? Here’s What You Need to Know

Expanding Your Off-Grid Solar System? Here’s What You Need to Know

JEREMY CHAMPT, Senior Sales Tech at Wholesale Solar​

There’s nothing quite like the sense of independence that comes from living off-grid.

But with that sense of freedom comes the responsibility of providing for your own energy needs – and it can be frustrating if your solar system struggles to supply power for the things you do on a daily basis.

You might find that your energy needs have evolved over time. Or maybe the system wasn’t sized to accommodate surges of heavy usage, and you need a little extra juice to cover peak output periods.

Thankfully, most off-grid systems can be expanded with additional panels, inverters, and a bigger battery bank.

When does it make sense to expand?

Before we tell you how to expand your off-grid system, you should work out why you need to add on to your system in the first place.

There are a few situations where modular expansion makes sense:

  • Budget constraints. It’s fine to start with a small system, then expand in the future as your budget allows.
  • Increased energy consumption. Your energy usage can change if more people move on to the property, or you buy more stuff that needs to be powered.
  • Insufficient solar production. If your system wasn’t sized to account for high-usage periods, it might need a few tweaks.

Budget Constraints

An off-grid solar system is a big purchase. Not everyone has the cash on hand to buy a system that will cover 100% of their energy needs.

Fortunately, you can build your system in small installments rather than make one large purchase outright. It’s a great way to approach your off-grid installation  but it requires a bit of planning in advance.

Our designers always recommend building a system with future expansion in mind. Regardless of whether you choose a roof-mount or ground-mount racking system, make sure your setup leaves space to tack on extra panels.

You should also be aware that inverters and batteries have their own capacity limits. If you add more panels, you’ll likely pair them with new inverters and batteries to keep pace with the extra output.

Not sure what size system you need? Calculate an estimate here.

On the flip side, it’s also worth considering how much more expensive this piecemeal installation method can be the long run. You should be aware of the drawbacks of building a system step-by-step:

  1. Panel Consistency

If you go years between additions to the system, it could be challenging to find panels that are the same make and model as your existing system. Solar tech advances rapidly, and companies update their product lines to keep in line with the latest innovations.

Thankfully, this is not too big of an issue. Most panels have a standard voltage and size, so a new panel will likely be compatible with an old system. There will be cosmetic differences, but a mix-and-match system should function just fine.

In general, it’s fine to mix and match panels as long as they are within 1 volt. Electrical specs and sizes are standardized (60-cell and 72-cell panels are common). For example, if you have 60-cell panels, you’ll be able to expand with more 60-cell panels, regardless of make or model.

  1. Extra Installation Costs

When you purchase your system in installments, you end up paying a lot more in shipping and installation.

And if you’re working with a contractor, you’ll have to pay the same service fees twice. The labor always costs less if you can get the whole project done in one go.

But these surcharges are minor compared to the overall cost of the system. And it may be worth it to be able to break the purchase into installment payments.

And depending on your setup, you may be able to skip the contractor and handle any additions yourself.

The process for adding on new panels isn’t too complicated. It involves minor adjustments to the mounting hardware, like adding different clamps. Depending on the brand and frame size of your panels, you might be able to bolt it on to your existing hardware without any changes at all.

Do keep in mind that if you upgrade your system to produce more solar energy, you may also need to add another charge controller and make adjustments to your wiring so you don’t overload the existing circuitry. Electrical expansion can be complex and requires a healthy bit of knowledge and research or the aid of a certified electrician.

Our support rep Ricky learned first-hand that making wiring changes to his system was more challenging than it initially appeared. Read his story:

Going Off-Grid? Please Don’t Make the Same Battery Mistake I Did

Increased Energy Consumption

Sometimes your energy needs simply change over time, and you need to expand your system to keep up.

Did you install a well pump? Add a second refrigerator? Or maybe your household has grown recently  either new roommates or a new addition to the family  and you just need a bit more to cover the expanded usage.

In that case, you can add on to your existing solar system by purchasing more solar panels, inverters, or a battery bank expansion. It’s a great idea to talk to a DIY solar tech to understand which parts you’ll need to keep the system stable. If your current equipment isn’t on the market, they can recommend parts that are compatible with your current system.

Your Solar Panels Aren’t Producing Enough

If your panels aren’t putting out as much energy as you originally thought they would, the issue might not be related to the size of your system.

Other factors can contribute to lower energy output: temperature, shade, and the direction your panels are facing. Poor setup may cause an otherwise well-sized system to underproduce. In certain cases, reconfiguring your system can bring it up to its expected output.

Mounting Direction & Angle

If you live in the Northern Hemisphere, your panels should face true south. Facing panels directly into the sun during peak hours will maximize the energy you generate.

However, you can’t exactly change the orientation of the roof on a house you already live in. Many people have to settle for placement that’s “south-ish” or a split between east and west.

In this case, adding more panels is more cost-effective than trying to find the perfect orientation with your existing system. It doesn’t hurt to fine-tune your mounting orientation if you have an adjustable mount.

For a fixed tilt angle, your array should ideally be tilted at an angle approximately equal to your latitude, for optimal year-round production. If you use an adjustable pole mount, you can tilt to a steeper angle in the winter to optimize production throughout the year.

Realistically, it’s a lot of work to adjust mounts, and most people would rather leave it alone to avoid the hassle. But it is an option if space is limited and you need to squeeze that extra bit of efficiency out of your system.

Temperature & Location

Solar panels are rated at standard test conditions (STC). The tests are run in a controlled environment, with temperatures regulated to 77°F and an ideal amount of light shining down on the panels.

In reality, your living environment rarely matches these optimal conditions.

In fact, most panels produce about 10% less power than their rating due to heat, clouds, and other factors. A 300W panel might only put out around 270W on an average day. The maximum output is rarely achieved, except during clear sunny days with ideal conditions.

There is another rating system called PTC, which tries to account for real-world conditions. PTC ratings tend to give a more accurate picture of how panels will perform in the real world.

Before you size a system, take your local climate into account. Extreme climates translate into a larger knock on the rated efficiency of your system. Keep this in mind when sizing up an expansion for your solar array.

Shade

Solar panel production will be impacted by shade, and a few small shadows can have a big impact on your solar panel output. Solar panels need to be installed in full sunlight for optimal performance.

Some modern panels have features including bypass diodes and half cut cells that can help with shading. But if you are experiencing lower output, check to make sure the array is not being shaded throughout the day. Over time, it’s possible for trees to grow up and cast shade on your solar array, reducing its performance.

Also make sure your panels are clean from pollen, dust, leaves and other debris. Over time this can build up and start reducing performance if not cleaned off by rain and snow. Clean your solar panels with water and if needed, a small amount of mild detergent.

Aging Equipment

Over time, solar equipment will age and and drop in efficiency. Solar panels usually last for 30+ years, but the output decreases slightly every year. Most solar panels are guaranteed to produce 80% of their rated power after 25 years.

It could take years to notice the impact, but over time your panels and batteries will decline in efficiency. After 5-10 years, you may find that your production has dipped below your energy needs.

You should design your system to account for this efficiency drop. But if you didn’t take this into account from the start, it isn’t too hard to add parts to compensate for expected efficiency losses over the life of the system.

Adding To Your Off-Grid Solar Array

If you’re ready to move forward with an expansion, some of the easiest parts to add on to your solar system are the panels themselves. Most of the off-grid solar systems we sell have panels wired in strings of three. That means if you’re adding panels, you will do so in multiples of three (3, 6, 9, 12, etc.) – not one at a time.

Depending on your system, you may be able to add a few more panels to the existing charge controller(s). You could also install multiple charge controllers, but be aware: your battery bank can only handle a given amount of charge current. Eventually, if you add a lot of solar panels, you will have to upgrade your battery bank so that it can handle the additional influx of power.

Adding Panels To A Ground Mount

Because off-grid living is usually synonymous with wide-open spaces, many off-grid customers install a ground-mount system. Since you don’t have to climb on your roof to make adjustments, it’s very easy to bolt on new panels whenever you need.

This could work to your advantage if you plan to build your system over time. If you have the space, go with a ground-mount racking solution. You’ll have easy access to the system any time you need to make an addition or perform maintenance.

Adding Panels To A Roof Mount

In order to expand the solar array on the roof, you’ll have to add on more racking and connect the panels to the existing combiner box and charge controller, as long as it can carry the increased load of power.

Expanding a roof-mounted system can be a bit trickier, since space is limited. A portion of your roof may not provide a viable build space, if it faces the wrong direction or is covered in shade.

What happens if you run out of space on your roof?

The first option is to replace some modules with higher efficiency versions to bring you up to speed. If that’s not enough, you can also pair your solar array with an alternate power source like wind or hydropower. Be aware that these options are limited depending on access to local resources  it won’t be an efficient option in areas with low wind speeds or strong water currents.

Mixing and Matching Panels

Take care when mixing and matching old and new parts from different brands. As described in this article in Home Power:

“Solar panels have changed dramatically over the years…not that long ago, 80W 12V nominal modules were common; today, 200W (or larger)…are more typical.”

It is okay to mix and match panels, but make sure the new panels have the same or as close to the same operating voltage, watts, and amps possible.

For example, you could add a 270W panel to your existing array of 250W modules; both of these are 60-cell panels that operate at the same voltage. As long as the panel voltage is within 1 volt, the system will be fine.

Permitting & Code Compliance

Additional permitting may be required when you expand your system. Depending on the size of your expansion, you may have to have the plans approved by the authority having jurisdiction (AHJ) – in most cases, the county or city planning department.

Build your system by the books to avoid headaches down the line. Download our Solar Permitting Cheat Sheet to ensure your system is up to code.

Even if you’re off-grid and miles away from civilization, it never hurts to have all of your permitting taken care of. If you or your neighbor ever sell or appraise your land, permits will be useful to prove the system is built within your property lines and up to code.

All panels and equipment should ideally be certified by UL to be permitted in the U.S. UL is an organization that ensures PV equipment passes rigid safety and quality standards.

More Inverter Power!

Most of the off-grid inverters we sell are “stackable,” which means you can nest multiple inverters together for increased power output. This is especially useful if your usage increases over time and you need more power on tap.

Adding another inverter isn’t always simple. The circuit breakers and wiring in your system likely aren’t designed to support another inverter. In some cases, the entire inverter system may need to be rewired. But if you anticipate expansion when you build your system, expandable power centers are designed for this purpose. You can add extra inverters and rewire them to a central hub — no extra wiring necessary.

A bigger inverter may require a larger battery bank to handle the increased output. The inverter manual should indicate minimum battery bank size, typically 200-400 amp hours minimum per inverter.

Expanding Your Battery Bank

The process for expanding your battery bank depends on the type of battery you have – either lead acid or lithium.

When you add a new lead acid battery into an old bank, the new battery takes on the capacity and other characteristics of the existing batteries. When you add more batteries, they drain down to the level of the old ones.

This might not be a big deal if the battery bank is only a year old. But it’s usually it’s not a good idea to expand a lead acid bank after it’s been used for a several years. Simply put, your new batteries won’t hold as much power as they could when you mix them with older batteries.

This is one area where we recommend planning for extra capacity to future-proof your system. With proper maintenance, you can extend the life of lead acid batteries to 7-10 years. You don’t want to tack on more batteries halfway through and instantly have the new batteries run at sub-optimal efficiency.

You can increase your battery capacity by wiring in more batteries in a parallel circuit. A parallel circuit combines the positive and negative battery connections, to increase the current (in amp hours) while maintaining the same voltage.

Diagram showing series wiring versus parellel wiring

However, there is a limit on the number of lead acid battery strings that can be wired in parallel. Three parallel strings of batteries is the recommended maximum. One or two is more ideal: they will charge and discharge more evenly, which makes them last longer.

Lithium battery banks are easier to expand because there are built-in electronics to manage the battery charge and balancing. Certain off-grid lithium batteries can be expanded over time, including Simpliphi and Discover AES batteries.

If you’re pre-arranging your system for future expansion, lithium batteries are the more modular and expandable option.

They are also more efficient, safer and tend to last longer – which comes with a price premium, of course.

If you’re not sure where to start with your system expansion, our design techs can help you sort it out. Get in touch with a system designer to help ensure your upgrade is compatible and covers your increased energy needs.

Ground Mount vs. Roof Mount Racking: What’s the Best Way to Mount My Solar Panels?

Ground Mount vs. Roof Mount Racking: What’s the Best Way to Mount My Solar Panels?

courtney
COURTNEY JOHNSTON, Purchasing Manager at Wholesale Solar​

Once you have your solar panels picked out, it’s time to decide which mounting system is best for your living space, budget, and energy needs.

There are two types of solar mounting options: roof mount and ground mount racking systems. Roof mount systems affix to brackets on your roof, while ground mount systems are built into a foundation at ground level. See the comparison images below for examples.

Standard Ground Mount

Roof Mount

There are benefits and drawbacks to each, and both mounting systems have their merits depending on your project specs. This article will dive deeper into what we think about when we recommend ground mount vs. roof mount racking to our customers.

But first, a quick summary:

Ground Mount Solar Racking

Pros

  • Easy to access
  • Easy to clean
  • Easier to troubleshoot
  • Stronger racking overall
  • System is not confined to the dimensions of the roof
  • Cooler panel temperatures means higher energy output
  • No need to remove panels if roof is replaced

Cons

  • Installation is more labor intensive
  • Installation is more expensive
  • Requires more parts and pieces
  • Permitting process is more expensive
  • Takes up real estate
  • Not aesthetically pleasing to everyone

Roof Mount Solar Racking

Pros

  • Less expensive
  • Requires fewer materials to install
  • Installation labor cost is lower
  • Utilizes unused space
  • Easier to permit

Cons

  • Hard to access – especially if your roof is steep or slippery 
  • Harder to troubleshoot errors
  • Higher panel temperatures mean lower panel output
  • Space constraints on the roof limits the size of the system
  • Can be a hassle if you need to replace the roof within the panel’s lifetime (might install the system twice)
  • Putting holes in your roof could lead to water damage

Why Go Ground Mount?

The Perfect Alignment

No matter what kind of solar system you’re considering, this much is true: every solar array works best when it’s able to get as much sunlight as possible.

If you live in the United States, you’re north of the equator, so the sun leans south as the Earth orbits. Facing your array true south will capture the most daylight and produce the best results. However, if you live south of the equator in South America, it would be more efficient to face your system true north.

Getting the perfect alignment can be a little tricky for a roof-mounted system. It isn’t likely that your roof naturally faces directly into the sun.

Ground-mount systems can face any direction you want. You can align your system at the optimal angle so it points directly at the sun. For that reason alone, ground-mounted systems are most efficient, as they maximize access to the sunlight that powers the array.

Benefits for Off-Grid & Grid-Tied Consumers

The perfect angle isn’t the only thing that makes ground-mount arrays more efficient. Being raised off the ground allows for better airflow and cooling, which means your panels produce more energy.

Most solar panels are tested at an average of 77° Fahrenheit – a normal sunny day, but nothing too extreme. But when it gets hotter than this, and the panels grow less efficient, producing 10-25% less electricity. The semiconductors suffer greater resistance to the flow of electricity. Think of it like squeezing the hose when there’s water running through it.

Proper airflow and cooling keep your panels running in optimal conditions, which is a clear advantage for ground-mount racking.

Giving You Room to Grow

If you’re installing on your roof, chances are you’ve got limited space to make the most efficient array possible. Should your energy needs change in the future, it could be challenging to add more panels to your current system.

When you go ground-mount, you’re under no such restriction – assuming you have the space in your yard. You can expand your array after the initial installation, and many ground mount racking options allow you to bolt on new additions easily.  

This means if you add on to your property and require more power, or if you find that your initial power supply just isn’t cutting it, you can add more panels as needed with minimum fuss.

Accessibility 

Another major benefit to ground mounted solar is accessibility. Solar systems require a lot of trial and error, especially in the installation phase. It’s a pain to have to get up on the roof every time you need to work out a kink with your system.

This is an even bigger selling point if you’re considering a system with microinverters and optimizers. With those accessories, there is a component under each solar panel and they can be difficult to replace on a roof-mounted system.

What happens if a microinverter in the middle of the array breaks down? In that case, you would have to remove several panels to access the source of the problem. When your system is on ground level instead of high up on the roof, it’s easier to troubleshoot panels and accessories.

Ground mount also makes it easier to clean your panels and perform routine maintenance on them. It provides you with more peace of mind to know you won’t have to risk your safety every time you need to brush snow off the panels, wash off dust and pollen, or remove debris from under the panels. There are also pole mounts available, which are ideal for heavy snow areas. Pole mounts can be constructed with adjustable tilt angles to maximize energy production and easily shed snow in the winter months.

Drawbacks Of Ground-Mounted Solar

Now for the drawbacks of ground-mount racking that you might want to consider.

In general, a ground mount is a lot more complicated to install and requires more money upfront to get the job done. If your primary concern is seeing the maximum return on your investment into solar panels, roof mount could be the way to go. The permitting process will be lengthier for a ground-mount system. And it will take up more space on your property, which you may prefer to use for something else.

More Labor Intensive & Requires More Cost Upfront

The main reason why a ground mount requires more cost upfront is because the system requires more parts to be assembled.

Think of it this way – when you place a solar array on the roof, half of the structure has already been built for you. But when you place a solar array on the ground, you have to build a sturdy roof-like structure to hold the panels in place.

This process involves getting your soil surveyed to make sure it can hold the system firmly in place, digging large holes, and paying extra for parts to build a suitable foundation for the panels.

Roof-mounted systems skip a lot of these costs. Assuming your roof is in good shape and doesn’t have structural damage, it should be strong enough to support the weight of the solar array. You don’t run into any of the hassle of building a brand new foundation to hold the panels in place.

Ground-Mount Racking Requires a Longer Permitting Process

Additionally, the city or county you live in might have a heavier hand in the installation process, since the system is considered a new structure. Depending on where you live, you will have to go to the authority having jurisdiction (AHJ) and obtain a building permit.

This will add extra challenges to the process. You’ll need to:

  • Submit a design plan
  • Consider soil type and property line setback requirements
  • Pay permitting fees

Ground-Mount Takes Up Real Estate

The final drawback to ground mounted solar is that it takes up a lot of space on your property. When you mount a system on your roof, it will be more discrete, and you get to keep the space on your land to do whatever you please.

The space issue isn’t a big deal if you have a large property. People who live out in the country tend to be able to find space for a ground-mounted system that won’t interfere with how they live the rest of their lives.

But if you own a smaller property, your roof may be the only place your solar array will fit. In some cases, a ground-mounted system isn’t even an option.

If space isn’t an issue, the decision often comes down to aesthetics. For those that consider ground mounted solar an unsightly blemish on their land, there are some artistic or unique installation options out there, such as those featured below.

But for the most part, people are proud of their solar arrays because they are a cutting-edge technology that represents freedom from the power company and total independence.

We like it when people show off their systems with a sense of pride. But there’s nothing wrong with preferring one look over another. For buyers who have the luxury of space, the decision often comes down to whether they think ground or roof-mounted systems look better.

Key Points To Consider:

Go with a ground-mount system if you want to simplify the maintenance / cleaning process and maximize energy output over time. There are three main questions to ask yourself to make sure ground-mount will work for you:

How much are you looking to spend upfront?

A ground-mount racking system requires more labor and parts to install it. You may need to partner with a contractor to get the job done, and the permitting process will be lengthier and more expensive.

But consider this: once the panels are installed, the upfront cost will be offset down the line by a more efficient energy output. There’s also less cost and hassle involved if you have to remove the panels for re-roofing.

You’ll shell out a bit more cash at the start, but the effort will pay for itself over time.

What kind of soil do you have?

If your property is on bedrock or if you know the soil is going to be really difficult to dig into, you might want to put the panels on your roof. Hard soil can make installation costs for ground-mount systems skyrocket. It’s not impossible, but you’ll need to rent heavy-duty equipment to drill into the ground.

There are also a few workarounds with ground-mount options to keep the digging to a minimum. A ballasted system might be a good solution. Learn more about the different racking options available in our article covering frequently asked questions about ground-mount racking systems.

Will you need to expand your system?

If you don’t plan on living off-grid, a rooftop system will probably be more than enough for your energy needs. However, if you are planning to go off-grid, the ground mount will allow you to add more panels as your energy needs change over time and you will get the benefit of a built-in tilt that can face towards the sun more easily than your roof.

When is Roof-Mount Racking Better?

Neither mounting system is “better” than the other – the choice depends on how your budget, energy needs, and lifestyle come together. A roof-mounted solar system tends to be a better option for customers who:

  • want to maximize their ROI
  • want a system that is simpler to install
  • don’t have a lot of space
  • want to spend less money upfront

Less Materials & Labor Means Less Cost Upfront

One thing that makes a roof-mounted solar system an easy sell is that it requires less time and money upfront to install.

When you put a solar system on your roof, the most complicated part of the structure is already in place. You don’t have to dig holes, get the soil surveyed, worry about your property line, or purchase expensive materials like poles and concrete.

The set-up is ideal for grid-tie customers that want to make a smart investment; installing on the roof instead of the ground can save you thousands of dollars.

Makes Use Of Unused Space

More often than not, a roof mount is used in a residential setting where there isn’t a lot of space for a ground-mount system. You might live in a condo or tightly-packed suburb. What scarce yard space you have might be better used for barbecues or a place for the kids to play. Mounting panels on the roof allows you to use space that would otherwise be useless, saving the rest of your property for the things that matter most.

Even for people with lots of land, some choose to install solar panels on the roof because it’s more inconspicuous. It keeps the space on your property free for things like raising animals, farming, and outbuildings. Roof-mounted systems keep the clutter off your land, so there’s more room to get things done.

Added Insulation & Protection

One unexpected benefit to a roof-mounted system worth mentioning is that it protects the roof from degrading elements like UV light, wind, rain, and snow. It will also keep your structure more insulated. If you’re living off-grid, this can be a nice way to keep the house naturally warmer at night and cooler in the daytime.

According to this article from Earth Sky, students at UC San Diego found that solar panels kept the roof an average of 5° Fahrenheit cooler than an exposed rooftop, which saved the building an average of 5% on cooling costs. Those savings are on top of what you’ll save on your energy bill anyway by going solar.

Easier To Permit

Are you one of those people who doesn’t like to get tangled up in bureaucratic procedures? A roof-mounted racking system is perfect for you. It involves a much simpler permitting process. You can submit the blueprints for your home to show whether or not your roof is structurally sound, and you’ll have to make sure your wiring and electrical systems are up to code. This typically won’t be an issue unless you live in an old home.

There’s no extra design paperwork to submit, because you aren’t building a new structure on your property – something that would lead to a much longer approval process.

Drawbacks Of Roof-Mounted Solar

What makes people shy away from roof-mounted systems? There are a couple downsides to consider:

  • Inaccessible due to their height
  • Less efficient, depending on the positioning of your home
  • Harder to modify and troubleshoot
  • Space constraints on smaller rooftops

Accessibility Makes Things Harder To Troubleshoot

For anyone that’s ever installed Christmas lights or cleaned out the gutters on their home, you know what a pain it is to get up on the roof. Depending on your mobility and planned level of involvement in the installation process, you may want to consider the accessibility of your roof. Depending on the pitch and what kind of material your roof is made out of, you may not want to risk getting up there. For example, metal roofing is really slippery.

Less Efficient

Roof-mounted systems are rarely as efficient as ground-mount systems. Rooftop solar panels can’t always be aimed directly at the sun. It’s a lot harder to angle an array on an existing structure so that it is optimized for full power consumption during peak hours.

You’re at the mercy of the built-in specs of your roof, which means you can’t always get the panels facing true south (above the equator) or north (below the equator). To compensate, you may have to buy a few extra panels to match the output of a perfectly aligned ground-mount system.

Space Constraints

The average roof area on a standard, medium-pitch roof in America is 1,500 square feet. Some of this space will be unusable due to chimneys, vents, and other obstructions. There’s not a lot of space left to work with.

Once your system is in place, it will likely be impossible to add on to that system if you need to increase your energy production. If your family grows or you add an extension to your home, it could be challenging to add extra panels to adapt to increased energy consumption.

Key Points To Consider

If you think rooftop solar is the best option for you, be sure to consider some commonly overlooked questions:

How old is your roof?

A roof and a solar system have a similar lifespan, so it makes sense to install them at the same time. Roofs less than 5 years old will likely be fit for solar panels. Any older than that and you at least want to consider whether it’s a good idea to replace it at the same time you install the panels.

If your roof is really old, there may be damage, leaks or structural integrity issues to worry about. It will need to be in good shape to support the weight of the solar array. Try to anticipate roof repairs before installing your system. It’ll be a huge pain in the butt to repair your roof after the panels are installed.

Does your HOA have constraints on where you can mount your panels?

Depending on the solar access laws in your state, a homeowners association (HOA) can prevent you from installing solar panels. Before you purchase your solar system, check in with your HOA to see if they have any guidelines regarding solar. You can negotiate any problems with them while you get the permitting in order.

How expensive is your electricity?

Even though solar panels are an excellent investment, it requires a big financial commitment upfront and it can take time to get a return on that investment depending on your energy consumption. If your energy consumption is small, your savings will be too. A lot of those savings can depend on your state and whether or not you live in a remote area that has expensive electricity. So even though we are big supporters of solar, it’s not for everyone – it really depends on your core goals.

To discover your key goals and find the perfect solar system for your specific needs, download our Getting Started With Solar Guide.

Install of the Month – May 2018

Install of the Month – May 2018

Defying Expectations with Tom M.

It feels great to prove your doubters wrong. Just ask our May Install of the Month recipient, Tom M.! He installed his DIY system for two and a half times less than what other solar companies wanted to charge him. Now, he’s free from the power company’s ever-increasing rates.

This month’s Install of the Month goes to Tom M and his large grid-tied installation in Albuquerque, NM.

When Tom started to tell people he wanted to go solar, they looked at him sideways. Albequerque has a long permitting process and strict electrical requirements. And he would face push-back from his Homeowner’s Association. But he knew the long-term rewards were worth the effort.

Tom didn’t plan on going the DIY route at first. He contacted a few local companies for quotes. But they tried to nickel-and-dime him on installation charges and wouldn’t customize the system to his liking. He soon got to the point where he knew that he would rather do it himself.

Tom contacted Wil at Wholesale Solar, who is also a New Mexico resident and familiar with local regulations. 9 days after he got his equipment, Tom had installed his own solar PV system.

When it came time for inspection, his HOA had to admit Tom’s work well exceeded their expectations. And the electrical inspector? They said it was the largest self-installed system they’d ever seen, and they’d never seen one done so professionally.

Interview with Tom

What was your primary reason for adding solar to your home?

Saving money because of constantly increasing rates from the local electric company.

Did you have any previous DIY experience?

I am a self taught DIY’r. I have a great workshop and lots of experience in home repair and other projects.

What was the most difficult part of the installation?

The most difficult part was getting the proper permits through the city. The building permit was just a payment, but the electrical permit required passing a city electrical test, following NEC 2014 rules, to allow work on my personal residence. I was also required to get a reroof permit due to the type of installation that I performed. The HOA also only provided a conditional approval since they didn’t feel it was possible for a self install to meet their requirements. However, it exceeded their standards and received compliments from all the neighbors.

How many helpers did you have?

Family helped by handing tools up to me on the roof, otherwise no additional assistance.

Did you hire a contractor?

I did not hire a contractor for any part of the installation

Were there any unforeseen additional parts or tools you needed?

I needed engraved placards for outside labeling of the equipment. Due to removal of 9 pallets of concrete tile and lifting 34 panels up, a forklift was a helpful tool in getting equipment and parts up and down from the roof.

How long was the full installation process?

Total installation time was 9 days. The permitting process was over a period of 3 months. This time included removing concrete tile then re-roofing with asphalt shingles to protect the house under the panels. Due to the HOA requirements that no more than one foot of conduit be exposed, I put all penetrations under the panels to protect them. I also installed chicken wire around all 4 sides of both arrays to keep the birds out. Concrete tile was then replaced up to the edge of the arrays to make it look like the roof was tile. The arrays are embedded at a level no higher than the concrete tiles.

How did it feel to get your solar project finished?

A true sense of accomplishment, and a great feeling when the electrical inspector stated that he had not seen a self install system that large and one that had been done so professionally.

Who else did you consider before choosing Wholesale Solar?

CST Solar and Positive Energy in my city. But when they started charging for every little item and when they refused to install the way I wanted, I got fed up with them and decided to install myself. Their cost was two and a half times as much as what I spent.

What was your total solar install costs? (Ball Park)

$24,000

How much did you save on your taxes

$8,000

Components in Tom’s custom system:

Tom's Solar Breakdown:

  • Cost of Contractor: None
  • Cost of Electrician: None
  • Total Hours to install: 9 hours
  • Design Output of kWh per year: 19,200 kWh
  • Federal Tax Incentive: Qualifies for $8,000 U.S. Federal Tax Credit
  • Utility rates per kWh: Varies: different rate plan options and TOU rates in place
  • Average Monthly Utility cost: Varies: different rate plan options and TOU rates in place

The Full Story in Tom's Words:

We wanted to be the first in our neighborhood to have solar…

We started thinking about solar when we bought a nice 50 acre piece of property in eastern Arizona in 1998. The closest power was 9 miles away and cost prohibitive, so solar became the answer. Well, as with all things in life, the only constant is change. Having children, and a change in career that moved us overseas put the whole project on the back burner.

Over the years, the power companies continue to increase their costs, and our increasing need for more and more power has made us reevaluate things. 

Fast-forward to 2016, and life has started to settle down. Over the years, the power companies continue to increase their costs, and our increasing need for more and more power has made us reevaluate things. We still have the property in Arizona, but we are focused on daily life in our home in Albuquerque, NM.

One day while shopping in Home Depot, there was a sales representative from a local solar company. Out of curiosity I asked them to come out to the house for an evaluation and quote. I knew that we were going to be one of the larger residential systems that they would design to install.

COMPLICATIONS… AND A SURPRISE EXTRA $20,000 

We ran into complications. There were limitations from the power company, the city mandated that our system could be no larger than a 10kW grid-tied system and our the Home Owners Association said that the panels would have to be parallel mounted to the roof and be within 4 inches of the existing roof. Also we should have less than one foot of conduit exposed on the roof, and that there should be limited additional equipment installed on the outside of our house.

After taking some measurements, they came back to us with a quote of $32,000 to have a fully installed and completed system. We were also informed that Nusenda Credit Union was the only financial institution in our area that would provide loans for solar. It is refreshing to think that they see the potential and return on investment when this cutting edge technology is done properly. However, we did not need this service because we chose instead to pay cash. Our return on investment would be immediate for us.

We signed a contract from the solar company, and then came the change orders and additions. Because we were splitting the arrays between two buildings, they wanted to charge almost $5,000 for trenching and putting conduit in the ground. Additionally, the 75 foot run between buildings would cost almost $500 dollars for the two 10 gauge DC wires to be connected to the system. We were told that they would be unable to tie into the existing power panel, as it would need to be upgraded to a 200 Amp service. Our service at the time was 100 Amps. Finally, they said that they would need to outsource any roof issues to a roofing company.

The system that they designed for us would be 14 panels that would be pointed due south on the workshop, and 20 panels that would face due west on the house. The workshop was one string, and the house would have two strings of 10 each. In the garage, we installed two SMA grid tie inverters. By having 3.8k for the workshop, and 6k for the house, we would be below the 10k maximum imposed by the power company.

We originally had wanted a system that was enough for our total needs. When we showed them a one line drawing of how we wanted the system, they said they couldn’t do it that way because it would take too much effort to install and be cost prohibitive. I was sensing that we didn’t fit into their cookie cutter design and that they may not have installers that were skilled for this type of work. As the customer, we wanted it our way and were willing to pay the cost differential. After consulting with their designers, managers and technicians for 6 months of design, they gave us a new estimate for almost $52,000. Imagine the look on our faces when we saw the new cost and the return of investment changing to about 15 to 17 years. We politely asked them to leave after deciding it was time to pull the plug due to the cost and inability to work to our specifications.

After consulting with their designers, managers and technicians for 6 months of design, they gave us a new estimate for almost $52,000. Imagine the look on our faces when we saw the new cost and the return of investment changing to about 15 to 17 years.

At dinner that evening, we discussed the events of the previous months, and decided that I was handy enough, and should consider doing the install myself. The next day I began the long process of obtaining permits, and making drawings and designs. We looked for suppliers of equipment, and found Wholesale Solar. We had an idea of what we wanted, and with the expert assistance from Wil Burlin, we started the process on our own. It took two years to find a contractor that would agree upgrade the power panel to the house. Due to construction changes, a new underground feeder, meter can, main disconnect would need to be installed. While we were at it, we had them move the service panel into the garage so that we could have better access and would not have to go outside at night in the rain to check a breaker.

At dinner that evening, we discussed the events of the previous months, and decided that I was handy enough, and should consider doing the install myself.

 

CHOOSING DIY 

Now to the good part…. We contacted Wil again, and he still had our original specifications. With a few changes, we finalized the order. Within 3 weeks, we received our shipment. During those three weeks, we ordered all the additional items we would need for our custom install, and I also started the permit process. For several weeks we would be receiving packages containing heavy duty switches, wire, breakers, conduit, ground lugs, labels, roof flashings, and waterproof boxes, from UPS, FedEx and USPS. It was like Christmas in April.

Also during the time that we were waiting for delivery, we worked on prepping the roof. We didn’t want the panels to be installed on top of our tile roof, so we removed the roof tiles. We found that the underlayment had water damage. If the local solar company contractors would have installed their system on top of the tile, we wouldn’t have known how much damage we had underneath.. Once the tiles were removed, we placed new underlayment, and installed a good 30-year shingle with all the proper flashings for a weatherproof roof. We also had our local roofer come out and reseal all the skylights, roof penetrations and other problem areas.

Next, we installed the Flashfoot 2 mounts and weather tight conduit flashings. We cannot say thank you enough for the Flashfoots as they were simple to install, and provided a weather tight and sound foundation for the rail system. Then we installed of the rails, and made sure they were all level and true. This is probably the most important step! Make sure they are straight, level and tight, as it will make the rest of the process go extremely quick. It is amazing how much a simple string line can do to help make everything square, true, level and straight. Hint… Don’t skimp on the roof mounts, penetrations or the amount of sealant. Spend the time and money on it now so that you don’t have to take it off later.

When submitted, my design approval with the power company was flawless, and only took about 4 days. 

When submitted, my design approval with the power company was flawless, and only took about 4 days. The approval process with the city was a little more in-depth, and it took me four trips to the city’s planning office to get the drawings approved. We paid for the building permit, but we were not informed that we needed an electrical permit. Because we were doing a self-install, they could not provide us with a permit unless I took, and passed, the city electrical test which would allow me work on my own home. I passed, so we were then almost legal. Reroofing, due to the damaged underlayment, caused the need for a reroof permit. It seemed like the city was reaching deeper and deeper into our pockets. After paying $700, we finally had the permits we needed to start the actual work.

Installation of the panels came next, and it went very fast. We actually had 14 panels on the workshop in less than an hour and then 16 of 20 on the house in about the same amount of time. Connections were easy and the final connections to THHN wire were in junction boxes already located in the attics. Panels were connected to the equipment in the garage through wires in ¾ inch conduits. Inverters, switches, production meter, fire department disconnect, a Generator disconnect relay, and to make it look good, we used no flex conduits. It took a bit longer, but all electrical (even in the attics) was run through ¾ inch EMT conduit that was bent to give it that professional and industrial look. EMT conduit also allows for easier pulling of wire on long runs versus flex conduit that the contractors wanted to use. This all took a bit longer, but in the end made it look and function much better.

For the runs from the workshop to the house, we dug a trench, 6 inches wide 16 inches deep and put multiple runs of one-inch schedule 80 PVC conduits. We would then backfill the trench, and then lay 6 inches of concrete sidewalk over the trenched area

The electric wall in the garage also had extensive work and upgrades. The drywall was removed, and some conduits were hidden in the wall with a few junction boxes for access. Plywood was hung on the wall, and it was textured and painted. Equipment was then hung on the exterior of the plywood. How many times you’ve tried to hang something on drywall only to have it sag or fall off. By using the plywood, you cannot tell any difference from the other garage walls, but you are able to mount anything anywhere and know that it is secure.

The inverters, switches and conduits all looked great. We added more than the normal number of disconnects so that we can have an AC disconnect both inside and outside. We also added a DC disconnect for each string, before each inverter so that we can perform maintenance on part of the system without shutting the entire system down.

GETTING IT APPROVED

Once everything was complete, we called for an inspection of the three permits (City electrical, city reroof, and building. The reroof and building permits were passed, but the electrical inspector was going to fail the install because the paint had not been removed from behind the ground lugs in the disconnect switches, even though the grounding screws had good contact. Unfortunately, the inspector couldn’t come back that day. But he did say that if we sent him a photo of the modifications before 3:00PM, that he would approve it and put it into the city’s computer. We ended up receiving a full approval. 

Next, we called the power company. They came out about 5 days later to install the production meter and to turn the system on. We didn’t even have to be home for this. When we came home, we found the system was working, and that it had immediately started producing power. Better yet, our meter was running backwards.

Because we use SMA inverters, we have programmed them to connect to the Sunny Portal application on our phones where we can monitor the power from anywhere that we have an Internet connection. It sends daily reports to our phone at the end of each day. Our average power usage in April is 65kWh per day, and we expect more in July and August.

In the beginning of this installation, and the many approvals and inspections, our Home Owners Association only gave use a conditional approval for installation. It seems like they wanted control of our project, and since it was a major project, they gave only a conditional approval because they didn’t know if we could actually do the install to their standards. We didn’t want to hurt their feelings by telling them that our standards are higher than theirs. We do understand their concern that not everyone is skilled enough to complete this monumental task. 

Another stipulation they had is that you can only have tile or metal roofing material in our neighborhood, and since we put shingles on the house, it wouldn’t pass their standards. To get around that, we protected our roof with the shingles, installed the solar system on top of that, and then replaced the tile right up to the edge of the panels. This way the panels are recessed in-between the tiles and no one can see the shingles. We also get some very strong winds during the year, and believe that the lower profile of the panels compared with the rise of the tiles will put less stress on the panels.

We have not heard of any protests from the HOA, but have heard praises from from our neighbors.

The shingles will last for a longer time because the panels are protecting them, just as the panels are protecting the production and ground wires and roof penetrations. We have not heard of any protests from the HOA, but have heard praises from from our neighbors.

EASIER THAN YOU MIGHT THINK

To regress a bit, we talked with many others that have solar systems, and many complain that they have birds making nests under the panels. Think of that, a dry, protected, and warm place to build a nest to raise youngin’s? We would think the same. However, not wanting to encourage the birds, we spent a little extra on bird proofing them by installing chicken wire to the panels, then down to the roof and under the tiles. Once the roofing tiles were replaced, the chicken wire almost disappeared, and now we have no worries about birds. All power and ground wires are protected under the panels and all the electrical controls are in a nice protected garage. The only thing you see on the outside of our home is the production meter and a single fire department disconnect. Due to city regulations, engraved placards are required to be placed on the equipment. Through PV Labels on line, they were easy to work with, and they completed custom labels that should outlast the life of the system.

Although this was a family project, I performed most all of the work. My wife, and daughters would occasionally help by helping to move and stack the panels, handing up tools, light up parts in the dark, keeping me fed, or filling up my water cup to keep me hydrated. I’m glad we did it in April, and not in July. It was warm, but July would have been a lot more uncomfortable. I also made use of a used forklift that we had purchased last year for other projects. I was grateful to have it while lifting the panels and lowering the excess roof tiles. Without the forklift, I would have seriously thought about hiring a younger helper to help me move the 9 pallets of tiles from the roofs to the ground.

In summary, this all sounds like an unthinkable self install project. However, it looks great, and it was easier than you might think. The system from Wholesale Solar works great. Our total cost was about $25,000 along with some sweat equity. After federal rebates of $7500, the total price out of our pocket is about $17,500.

After federal rebates of $7500, the total price out of our pocket is about $17,500.

If we had financed this project, the return on investment would have worked out to about 4 years. But instead we are free and clear from payments. The total time invested was about two weeks for permits, and 9 actual days of installation.

Would I do it again? Absolutely. Do I recommend this to others? Absolutely.

The best thing about all of this is the freedom from increasing electrical costs. Would I do it again? Absolutely. Do I recommend this to others? Absolutely. It is a part of the house that just works for us and for our environment in a positive way. I guess the only thing that I have left to do is to spray the dust off of the panels from time to time.

Going Off-Grid? Please Don’t Make the Same Battery Mistake I Did.

Going Off-Grid? Please Don’t Make the Same Battery Mistake I Did.

By RICKY RAFFAINI, Tech Support Rep at Wholesale Solar​

I have always been interested in renewable energy, but when I moved into my grandma’s old cabin in Mendocino, CA, it was the last thing on my mind.

Yes, with the cabin came a small off-grid solar setup, but I was more concerned with abstract concepts like “peace” and “beauty.”

So at first, I was happy with the single 12-volt battery I had. It forced me to live a simple life without a bunch of electronics—always a good thing.

With the limited power available I was able to use my laptop, a few lights, a small speaker, and a phone charger. There was no cell service, so my phone never died, and I used kerosene lamps to read most nights.

It turned out to be one of the best experiences of my life.

But eventually, I was ready to upgrade my battery bank—mostly for the experience.

However, I had no idea where to start.

My first thought was, “This can’t be that hard.”

I quickly realized it was more complicated than I thought.

One of the first things I learned: it is so important to have an understanding of how lead acid batteries work before messing around with a battery bank’s wiring.

So I asked around for information, found some basic solar books (mostly outdated books from the local library), and used my phone to research batteries when I was closer to town and had cell service.

I ended up purchasing a couple of cheap marine or “deep cycle” batteries from the local hardware store on the recommendation of a new employee.

I realize now he probably didn’t know the difference between car batteries and the marine batteries they carried… but neither did I at the time, so fair enough. (A car battery’s power is measured in cranking amps, because the battery is designed to offer bursts of energy to start a vehicle—rather than slow discharge needed to run appliances.)

Luckily my limited research helped me decide on the marine batteries, which are designed to have a longer reserve capacity than car batteries.

All that meant in my case, however, was that it took me longer to destroy them.

Knowing what I do now, I’m a little embarrassed to say that I was nowhere near ready to install a battery bank—no matter how small this setup was. Here’s where I went wrong.

The failure happened because I didn’t know the difference between a series connection and a parallel connection.

Diagram showing series wiring versus parellel wiring
Series Circuit Wiring Vs. Parallel Circuit Wiring

In a series circuit, the current through each of the components is the same, and the voltage across the circuit is the sum of the voltages across each component.

Christmas lights are a good example of series wiring. If one light stops working, it blocks the power to the rest of the lights that come after in that circuit.

In a parallel circuit, the voltage across each of the components is the same, and the total current is the sum of the currents through each component.

When hooked up in parallel, each light will have its own path to the power source. If one light goes out, the rest will stay on since they are hooked up independently.

In short, series wiring increases the voltage but the amps stay the same. And parallel wiring increases the amperage but the volts stay the same.

And when I got the two new batteries in place, I had no idea what to do.

Now remember, I was working with just one 12 volt battery before, and now I have two 12 volt batteries, which created 24 volts when wired in series.

It’s also important to remember that my inverter (the heart of the system) operates on a 12 volt battery bank. So I’m limited to 12 volts for my battery system.

But wait, you say. You now have a 24 volt battery bank and a 12 volt inverter, that can’t work. Well, yes and no.

The way I wired it, which was in series, was of course wrong. And that’s because I was running a 12 volt inverter with a 24 volt battery bank.

What I should have done was wired the batteries in parallel at 12 volts, allowing my 12 volt inverter to play nice with my battery bank.

Diagram showing the original, wrong, and right way Ricky should have wired his batteries
Ricky's Mistake: Wiring Two 12v Batteries in a Series with a 12v Inverter.

On the flip side, I could have bought a new inverter that was 24 volt rated and would have been fine running with two 12 volt batteries in series (totaling 24 volts), but that would have cost me a lot more to upgrade, when all I had to do was wire my batteries correctly.

I’m still not sure if I caused any damage to my solar equipment. I would be surprised if you told me I didn’t.

My grandma warned me that maybe I shouldn’t attempt to upgrade my system, but of course I didn’t listen. Luckily, she seems to be a firm believer in learning through experience… So the time and money spent were not a total loss in her eyes. (Or maybe she was just trying to make me feel better about destroying her stuff…).

After this experience, I decided to pursue some real education in solar installation.

And I won’t lie—my inspiration came from wanting to make things right at the cabin. (Not to mention wanting to prove to myself that I could figure it out.)

My solar disaster was 100% my fault. And although my grandma has never expressed frustration over the “battery-turned-paperweight incident,” I am sure she would appreciate a more thought out and educated approach to make things right again.

That brings me to Wholesale Solar. I have always had an interest in finding a career path in some sort of industry that supported sustainable living, with solar at the top of that list.

I’ve worked in biodynamic farms in the mountains of Mendocino. I’ve also given water conservation a go with a sustainable plumbing company building rainwater collection systems and gray water gardens in Sonoma.

And as a part of that job I noticed that at every beautiful job site there was a solar array.

I was actively taking classes and pursuing my career, but I’m happy (and lucky) to say I fell into the Wholesale Solar team by chance.

I started working here in July of 2016, and eventually found my way into the technical support department. Which is funny—because I often help folks going through the same kind of failed experiment I did.

Solar takes a lot of time, patience, and effort to install and maintain. That’s something I learned the hard way, and something I hope to teach our customers.

I have so much respect for our customers after battling a tricky installation myself, and I am so grateful to finally be in a position to not only help my grandma, but also many other off-the-grid enthusiasts trying to live in an independent paradise.

Click to download our guide to getting started with solar power
5 Questions You Should Ask Before Installing Ground-Mount Solar

5 Questions You Should Ask Before Installing Ground-Mount Solar

courtney
COURTNEY JOHNSTON, Purchasing Manager at Wholesale Solar​

If you’ve read about the state & local incentives to go solar and maybe even looked into our free solar cost calculators, you’re likely convinced – going solar is a terrific investment. But once you’ve made the decision to purchase a solar system, that’s when the real questions begin.

If you’re a homeowner that has some acreage to spare, a ground-mounted solar array can be a terrific option for you. Depending on your budget, space, and energy needs, a ground-mounted system has a lot of benefits.

For starters, the system is easier to access and has no interaction with your roof – which means you don’t have to worry about damaging roofing materials, water leaking into your home, or moving the panels around in the case of a roof replacement.

However, before you bust out the auger, consider these five questions inspired by a conversation I had with solar professional Brady Schimpf. In addition to being the Technical Marketing Engineer at Ironridge, a company that produces mounting hardware for PV solar arrays, Schmipf has a lengthy background in solar installation.

Aside from Schmipf offering up answers to these questions about rooftop solar, he also clued me in on five key things many people misunderstand about ground-mounted solar – and shed some light on major compliance & property line issues that can cause all kinds of costly problems after installation.

Question #1:  “What are the different types of ground-mount solar systems and how do I know which one is best for my needs?”

Standard Ground Mount

When most people think of ground-mounted solar panels, they think of the image on the left (as featured in our Dec 2017 install of the month). This is what’s called a standard ground mount – where several poles are placed in the ground, and a racking system is installed on top to hold the solar panels.

The process of building this kind of system is similar to putting together a fence. You would first dig several holes that are a few feet deep, then set the poles in, and fill them with concrete. This structure would create the foundation for holding your solar panels.

A notable feature of a standard ground mount is that the panels are “fixed” – this means the tilt angle and direction is permanent. While the main benefit of this is that it’s cost-effective and easy to install the downside is that there is little to no adjustability and it’s not ideal for areas with extreme snow.

While concrete piers are always the most practical and cost-effective foundation for a standard ground mount, there are alternative foundation options including ballasted, driven piers, and helical piles. These are mainly used for large commercial or utility installations, typically when the soil is too hard or rocky to drill into.

With a ballasted solar system, it’s basically a standard ground mount with an added feature – concrete footings that are above the ground. Driven piers look like a huge pole, and as the name suggests, it gets pile-driven deep into the ground using specialized equipment.

Helical piles, also known as Earth screws, look like a giant screw. They also require special equipment for installation, similar to the driven piers. Additionally, all three alternative foundation options require working with a Professional Engineer (PE).

Pole Mount Solar Panels

Aside from standard ground mounts, you may also consider pole-mounted solar panels. When I consulted solar professional Brady Schimpf, he explained that pole mounts provide some interesting solutions that might apply to your unique situation.

For starters, pole-mounted solar panels are built in a similar way as the standard ground-mounted systems, but instead of digging several holes you would dig one big hole and set a huge pole into it. Then, the solar panels are mounted on top with a built-in tilt and swivel feature that allows you to adjust the panels manually or set up automatic trackers to improve your solar output.

While this sounds pretty appealing, Schimpf reminds consumers that what it really comes down to is the cost per watt. He stated,  

“In a residential system it’s way cheaper and equally as effective to add more arrays [solar panels] than have the ability to adjust a smaller array.”

However, there are benefits to a pole mounted system beyond energy output – the adjustable feature also allows you to lift the array above the ground to clear foliage, snow, and other obstructions. The height combined with adjustability makes a pole mount ideal for those that live in snowy climates. On the downside, pole-mounted solar panels are a lot more expensive, require a big concrete footing, and the large pipe is hard to work with.

Question #2:  “Does ground-mounted solar have to be off-grid?”

Both grid-tied and off-grid customers can use ground-mounted solar panels. The decision to use ground-mounted solar instead of rooftop solar usually has to do with space. For customers that have some acreage to spare, using ground-mounted solar can be a great option – but if you’re living on a smaller lot, or want a quicker ROI, you might want to conserve space and make use of the real estate on your roof. Ground mounted solar systems tend to be more expensive and labor intensive, but can be more efficient at capturing energy thus saving you more in the long run.

Question #3: “What are some things I should consider before installing ground-mounted solar?”

Before you purchase a ground-mounted solar system, consider the fact that it’s usually a more complicated installation process than putting solar panels on a roof. When you have a roof installation, half of the structure is already built. All you have to install is racking and the solar array. However, with a ground mounted system, you essentially have to build the structure of the roof from scratch, so the solar panels have something to sit on.

When I posed this question to Schimpf, here’s what he had to say:

“[Aside from space] one important thing to consider is your soil type. If you’re not familiar with what it is, you can get a local contractor out to do an evaluation for a reasonable fee.”

And depending on where you live, this could be an essential step. Some cities, especially those with certain soil types, strict building codes, and high earthquake risk, will require you to get your soil inspected and approved before you can move forward with your ground mount design. In that case, a soil engineer would look at the soil to determine its type and make adjustments to the foundation size and requirements of the design.

Keep in mind that all standard ground mount racking comes pre-engineered for all 50 states, but certain conditions in your area like heavy wind and snow and certain soil types may require special designs.

The key point here is that depending on where you live, you might need to meet with a local engineer to get your system approved and built to city standards.

So what are the best type of soil for ground-mounted systems?

Schimpf tells us:

“Basically anything that doesn’t have tons of large rocks and isn’t a hard-pan type material [works] well. Ground-mount works well on almost any other type of soil – it’s only an issue if you get into that [situation] with large rocks in the ground. That’s where it causes problems – but there are alternate ways around that…It’s more costly, but if that’s what you have there are options.”

Some of those options would be the more complicated foundations mentioned above – like ballasted, driven piers, or helical piles.

Question #4: “Do I have to get my property line surveyed before installing ground-mounted solar?”

One of the smartest things you can do before installing a ground-mounted solar array is to get your property line surveyed. According to Schimpf, issues with property lines come up a lot – usually after you’ve spent thousands to install a ground-mounted solar system. He recalled one scenario where a consumer built their solar system too close to the property line and the whole system had to be taken down and moved a foot backward.

“It’s very important to go through that process and understand property line setback requirements because if you install without a permit and you put [the system] too close to the property line, that can be a huge problem if you try to sell your home or get a permit to do other work on your property. Down the road, this can come back as a big issue.”

Property line setback requirements will vary quite a bit depending on what state or county you live in. For example, this document from San Diego County names the property line setback for ground-mounted solar arrays at a minimum of 3 feet. However, this document from the Department of Energy Resources in Massachusetts recommends counties in the state enforce 20-50 foot property line setback requirements (located on page 8).

To save yourself a ton of money and a massive headache, be sure to contact your local authority having jurisdiction (AHJ), which will be either your city or county depending on who issues building permits. To get a permit, you’ll have to go through all kinds of documented processes, including submitting a site plan. If you need assistance navigating the bureaucracy, be sure to download our free permitting guide.

Question #5: “Are ground-mounted solar panels safe & legal in my neighborhood?”

As long as you install your solar system after obtaining a building permit and purchase code-compliant materials, it’s entirely safe and legal. PV solar panels are compatible with most types of land use and permitting is typically handled on a local level.

According to Schimpf, when you install a ground-mounted solar array, there is not as much concern about fire as there is when you install on top of a roof, but UL 2703 code compliancy is still important. UL 2703 is a building code that requires PV solar racking materials, bonding, clamps, etc. to undergo rigorous testing that ensures they have the appropriate structural capacity, can withstand both high surges of electricity and don’t accelerate house fires.

And while the fire hazard element is more critical for rooftop solar panels, you still want to look out for UL 2703 compliant parts and avoid mixing and matching parts from different suppliers, as these parts may not have been tested together on a system level. Additionally, Schimpf recommends you protect the wires coming down from your solar array; they should be enclosed by a channel or raceway so that they’re not left open and exposed causing potential hazards.

Click to download our guide to getting started with solar power
Customers’ Biggest Questions About Rooftop Solar Panels Answered

Customers’ Biggest Questions About Rooftop Solar Panels Answered

courtney
COURTNEY JOHNSTON, Purchasing Manager at Wholesale Solar​

According to data from Consumer Reports, more residential homeowners are opting for solar power than ever before. From 2010-2015 the number of residential solar PV installations increased dramatically.

I surveyed three consumers who recently made the switch from PG&E power to sun energy, and they all said the same thing – their biggest concern during the purchasing process was their roof.

Many residential customers don’t have space for a ground-mounted solar power system. However, if your biggest concern is saving money and getting a quicker return on your investment, rooftop solar panels are likely the best fit anyway.

A rooftop installation is always more cost-effective because it takes advantage of an existing structure. With a roof mount, you don’t have to go out and buy pipes and concrete or pay for the extra labor it takes to install the system.

And although a rooftop solar system seems simpler at first glance, there are still a few important questions you might want to consider. In fact, here are the answers to five of the most common questions about rooftop solar power for home use.

Question #1: “Is my roof a good candidate for solar panels?”

Most residential customers considering the switch to solar power want to know whether their roof is even fit for solar in the first place. The truth is, solar panels can be installed on almost any type of roof – you just have to find the right mounting system for the job.

To get more information on mounting systems for rooftop solar, I spoke with solar industry expert Brady Schimpf, who is the Technical Marketing Engineer at Ironridge. According to Schimpf, “there [are] mounting systems for just about everything…but some are much more difficult, expensive, and labor intensive than others.” The first thing to consider before a roof installation is the material that the roof is composed of. The most common roofing material, composition shingle, is one of the easiest to install solar panels onto aside from a metal roof.

In general, solar panels are best installed on a sturdy roof that is made of composition shingle or metal, and things tend to be a bit more difficult on tile roofs – especially those that are so delicate that technicians can’t walk on them, like Spanish tile.

One technique an installer can use with a tile roof is to remove a section of tile and install shingles where the solar panels are going. This makes the solar system appear flush with the roof due to the raised height of the remaining tiles, and you won’t be able to see the shingle roofing underneath the solar panels.

Each type of roof will likely require a different style of mounting hardware, so if you plan on doing your own installation be sure to discuss those details with a solar consultant. For example, a low slope roof (a.k.a. flat roof most commonly seen on commercial buildings) can be tricky to install on, and typically requires hiring a roofing company to install flashings.

On the other hand, something like a metal roof can be much more straightforward. On certain types of metal roofs, a solar array can be clamped down without penetration, making it 100% leak-free. You might also check out this video about solar panel mounting options or this one below, which details how to mount solar panels to a roof step-by-step.

In addition to materials, customers should also consider the pitch angle of the roof, the size and shape of the roof, how much shading is present, the direction the roof is facing, and of course the age of the roof. All of these elements can affect how much solar energy your system is able to produce. If the system is installed correctly and optimized, it could potentially cover the cost of a new roof in energy savings in as little as 5 years.

Question #2: “Do I need a new roof to install solar?”

If your roof is in need of any major repairs, you will want to take care of them before you install your rooftop solar system. Solar energy systems have a lifespan of 25 to 35 years and taking a solar system down to replace a roof can be complicated and costly.

But generally speaking, this is only an issue for shingle roofs, which have the shortest lifespan. A shingle roof installed in the last 5 years is probably good to go for solar. For a roof that is older than that, consult a roofer to find out whether you need to replace the roof or perform major maintenance before installing solar panels.

Question #3: “Do rooftop solar panels damage the roof?”

One huge myth about rooftop solar installations is that it will damage the roof. On the contrary, a rooftop solar system can extend the life of a roof by protecting it from the elements.

Rooftop solar arrays are mounted slightly higher than the roof so air can circulate under the panels to prevent overheating. That being said, confirm that the technicians installing your rooftop solar system have experience with your particular roofing material and investigate whether the solar installation will void your original roofing warranty. Also, make sure you regularly clean debris like leaves and pine needles out from under the panels.

According to Schimpf, “Something a lot of new installers or DIY builders struggle with is damaging the shingles,” and the real issue with putting holes in your roof is the potential for water damage. As described by Schimpf, who has a long background in solar installation, technicians will install flashing underneath the shingles, and if they don’t take their time and lift the shingles carefully, it can damage the roofing materials making your home susceptible to water damage. Thankfully, much of those worries about water damage can be alleviated by some innovations in mounting hardware made in the last 5 years.

Schimpf described an elevated seal system produced by Ironridge that uses strategically placed metal flashing instead of rubber or sealant to divert water around the hole. This means homeowners would be reliant on an elevated piece of metal, which will likely outlast the home itself, over a rubber or sealant that has an unknown lifespan.

Question #4: ” Can I install a rooftop solar system by myself or do I need to hire an expert?”

Depending on your skill set, you can install a solar array on your own or partner with a contractor. Some Wholesale Solar customers handle a majority of the project on their own but hire contractors for some of the work. For example, you might want to pay a roofing company to install the flashings and then you can bolt on the rails and solar panels yourself. Any local roofing company can install flashings, and the company that installed your original roof will be able to verify that it won’t affect the original warranty.

Of course, doing everything yourself can cut down on the cost of your system and is perfect for a customer that wants to be highly involved with every step of the process. According to Schimpf, any DIY installer should try to find a mounting system that “goes together simply, has a low part count and is easy to put together.” Considering you’ll be working on an inclined surface, the less little parts you have lying around, the better. Schimpf compared the process to the “Ikea Cabinet Scenario,” where “you’ve got 60 different screws and fasteners, you’re trying to put it all together, and once the cabinet is assembled you realize you’ve got it all backward.”

Schimpf also noted an essential piece of information regarding fire code compliance. He recommended finding a mounting system that is UL2703 listed, which means it has been through rigorous testing to make sure it can handle large surges of energy, has the proper structural capacity, and won’t interact with the solar array to accelerate house fires. For more information on this and other key details regarding DIY installation, you can check out beginner to advanced webinars from Ironridge.

Question #5: “Where might I encounter hidden costs that decrease my ROI?”

When a customer asks how solar panels will affect their roof, they’re ultimately questioning whether they’re going to be faced with extra costs or headaches down the line. And this much is true – taking down and storing solar panels while replacing a roof can be costly.

One important point to make is that most solar systems have the same lifespan as the average roof, so as long as your roof is in good condition when the solar system is installed, you won’t have to take the solar panels down until it’s time to upgrade both the roof and your solar system.

So what does an expert on mounting hardware state as his biggest concern for rooftop installers?

“Keeping your roof membrane intact, keeping water out of your house… and taking the most time to make sure it’s done right.”

Some additional tips offered up by Schimpf involve commonly overlooked elements regarding mounting a junction box or rooftop conduit box. Customers should take the same precautions around water damage as is done with the solar array, otherwise, you’re really only completing half the job.

Additionally, be meticulous with your wiring. There will be cables that come down from every panel, and they need to be kept secure. If they’re drooping and blowing on the roof in the wind, the rough roofing material can wear through the insulation of the wire causing safety hazards. Also, as explained in this article by Mark Durrenberger from New England Clean Energy, unsecured wiring can provide a nesting location for small animals and collects debris more easily.

The wiring behind your panels can be secured using metal clips that keep everything tight and neat– just make sure the materials are made for solar use, like these metal clips from Ironridge. A cheap bag of zip ties won’t be able to withstand the elements in the long term.

So whether you’re ready to hop on the roof and install your own solar array or want to hire an expert, there are many design elements to consider. Some of the main takeaways are safety, the longevity of the parts used, and code compliance. If you’re ready to explore your options for residential solar, download our free getting started with solar guide.

 

Click to download our guide to getting started with solar power
Do Solar Panels Increase Home Value?

Do Solar Panels Increase Home Value?

By JOHN GRENVIK, Design & Sales Technician at Wholesale Solar​

A recent study by the Lawrence Berkeley National Laboratory concludes that solar panels increase home value by $14,329 on average. Homes equipped with solar power systems sell for 3.74% more than comparable non-solar properties.

One of the strongest arguments for solar energy is that it’s an investment that pays for itself. Any upfront costs are paid back in the reduction (or elimination) of energy bills, and solar customers can reasonably expect to see a return of at least 2-3 times their initial investment over the life of the system.

But those numbers assume you live in the same house for the full duration of the warranty – which often isn’t the case. And one of the reservations holding a lot of people back switching to solar is the fear that they might not live in their house long enough for the significant up-front investment to pay off.

If you own your home, this research should assuage those fears. Outfitting your home with a grid-tied solar energy system drives up property values and offers an enticing selling point for real estate agents to market a listing.

Even if you don’t live in your home long enough to break even on energy costs, the premium that home buyers are willing to pay to move into your solar-ready home will be more than enough to cover the investment.

Solar ROI Calculator

To figure out how much you could save by going solar, check out our guide to calculating the ROI of your solar electric system in our resource center.

Solar Homes Sell For $14,329 More On Average

The study evaluated the sale price of 22,822 homes across 6 states to determine what effect solar power systems have on home resale value. The study compares the sale price of 3,951 PV Homes (homes equipped with photovoltaic systems – a.k.a., solar-powered homes) to 18,871 Non-PV Homes.

The research finds that, on average, solar panels increase home value by $14,329 – or 3.74% more than their non-PV counterparts.

Since the average system costs $10,000-$18,000 in materials, homeowners can reasonably expect to recoup the cost of the hardware when they choose to sell their home. That’s on top of the expected savings from reduced energy bills and tax incentives, which can already pay for the system 2-3 times over the life of the warranty.

As a bonus incentive, some states don’t count PV systems toward the value of your home when calculating property taxes. Adding a $15,000 kitchen will raise your property taxes, but a $15,000 PV system might be exempt. This comes down to local regulations, though, and certainly isn’t true everywhere in the U.S.

Digging Deeper Into the Data

Of course, real estate is a complex market, with countless factors influencing the valuation of a property. National averages will never tell the whole story. So let’s take a closer look at the data and see if we can uncover some more specific information.

Diminishing Returns on Larger PV Systems

One conclusion the authors of the study draw is the existence of a “green cachet” for homes equipped with PV systems. Solar-equipped homes sell at a significant premium, regardless of the wattage output of the system. The sale price of homes with more powerful PV systems did not increase proportionally to the installation cost of the system.

This suggests that homebuyers are prepared to pay more for the distinction of owning a “solar home,” regardless of the efficiency of the system, or its ability to fully cover their expected energy usage. They will pay marginally more for larger systems, but not in proportion to what the system is actually worth.

For sellers, that means it might make sense to install a modest grid tie system that relies on stored solar energy most of the year, but pulls from the electric grid during heavier usage periods, like when the A/C runs on full blast during the dog days of summer.

This may afford you the flexibility of marketing your listing as a solar home, while keeping installation costs down and turning a profit on the system when the sale goes through.

Of course, taking on an extra project like this adds time, labor costs and risk to the sale process. It may not be worth the investment, especially because…

Solar Homes May Take Longer to Sell

The study also found that, on average, solar-equipped homes take slightly longer to sell than their counterparts. Solar homes spend an extra 8 days on the market before they sell, as demonstrated by the chart below.

Solar homes spend slightly longer on the market before they sell. Source (p. 29)

Note that there is quite a bit of fluctuation in the data on a state by state basis. This could be attributed to a couple factors:

Small sample size in some states

The data from CA is much more robust than other states in this study, which may explain why its numbers come closest to the national average.

Incentives vary by state

Some states offer stronger incentives for buying a solar home, while others offer nothing at all. Solar homes may languish on the market for much longer when there is no incentive for owning a solar-enabled home. For example, some states offer a break on property taxes if you own a solar home. It might be more enticing to buy a solar home in those areas.

We strongly recommend exploring our guide to State Solar Incentives if you’re in the market to understand how the dynamics might change based on your location.

Local perception of solar

Solar power has been more broadly adopted in places like CA and FL, where sunshine is plentiful and there are strong tax benefits for going solar. Other states lag behind in adoption and education on the topic.

In areas with lower electricity costs and poor benefits for solar adoption, the awareness of solar as an viable energy source tends to be quite low. Buyers may hesitate to buy a solar-powered home because they aren’t convinced the system is reliable. They also may not understand the long-term benefits, making solar homes a harder sell.

Solar education in lower adoption states can be a major stumbling block. In many cases, buyers don’t understand the difference between grid-tie and off-grid systems. They tend to assume all solar energy systems are off-grid, which rely on panels to generate 100% of their energy and run entirely on a battery storage system. The fear is that they’ll be stuck without power if the solar array goes out and they don’t know how to fix it.

In reality, most systems are grid-tied. They generate their own energy, but still hook into the public utility grid. The solar panels don’t need to generate 100% of your home’s electricity — the grid can pick up the slack in periods of heavy usage. And if the power goes out, it’s on public utility workers to fix the issue and get things back up and running as soon as possible.

In areas where solar energy is less popular, a little education may be necessary to convince buyers that a PV system is a reliable way to power their home.

Learn more about the difference between off-grid and grid tied systems with our Getting Started Guide.

Newer Systems Are Worth More

Okay, this one should be common sense – but just to be thorough, it’s worth pointing out that the data backs this up.

Newer PV systems are made from more efficient materials, have more years left on their warranty, and are less likely to be due for replacement parts (like a new inverter, which you can expect to replace about halfway through the life of a system). As PV systems age, their value depreciates, and they tend to be worth less when you put your home on the market.

Pretty simple – newer installations are a greater boon to property values, as you would reasonably expect.

Leased vs. Owned Systems

Finally, the premium only applies to homes with host-owned PV systems. If you agreed to a solar lease or PPA (Power Purchasing Agreement) with the developer who installed the system, you likely won’t see much—if any—of the higher sale price returned to you as profits. In these cases, buyers will request the previous owner pays off their lease or PPA agreement, which offsets the additional value built into the final sale price of the home.

The extra cash from the sale only goes into your pocket if you have purchased your PV system outright. That’s one of the reasons we strongly recommend buying your system instead of leasing it.

Related Article: Should You Buy, Lease or Loan Your Solar System?

A Few Caveats

As with all research studies, it’s important to pay close attention to the methodology used to make sure we’re drawing the proper conclusions. Here are some important pieces of information about how this study was conducted:

  • The data spans home sales from 2002-2013.

The LBNL study only evaluates homes sold between 2002 and 2013. But more recent advancements in solar technology have made installations quite a bit cheaper since then, which may have an impact on their appraisal value in more recent home sales.

The most recent report on the cost of PV systems from the NREL (National Renewable Energy Laboratory) shows that in 2017, the cost to install a residential PV system in the U.S. is less than half of what it was in 2010. In fact, solar prices seem to have leveled off right around 2013 – the last year data was collected for the LBNL study.

As PV systems become more efficient to install, that may translate to a smaller impact on home resale values in the future. But since the premium on sale prices will likely shrink at the same rate as the installation costs, we still expect sellers to recoup the hardware cost of their system when they go to sell their home.

  • The research was conducted in 6 states: California, Oregon, Florida, Maryland, North Carolina, and Pennsylvania.

According to this ranking of the solar-friendliness of all 50 states, 3 of these 6 states ranked among the top 12 in the nation, and the worst was still close to average – Florida, at #28. With that in mind, the data skews heavily toward states with higher-than-average solar adoption. The impact of solar panels on home resale value will certainly be a bit lower for states lower down the list. You may see a smaller impact on property values if you live in a less solar-friendly state.

It’s hard to say for sure – the research is still limited, and we don’t yet have reliable country-wide data to draw from.

  • The study examines homes much more expensive than the national average.

The mean sale price of homes examined for this study was $431,964, which more than doubles the median home value in the US. The highest-selling home it appraised went for $899,000.

It’s hard to say whether solar readiness remains a strong purchase motivator once you get into the territory of high-end homes. We can’t think of a reason these trends wouldn’t hold true for million-dollar homes, but the LBNL doesn’t cover that market segment in their study, so it’s worthwhile to consider the dynamics may change for high-value properties.

For more modest homes, the data is much clearer. Smaller properties need smaller systems to cover their electricity usage. As you spend more on a PV system, the premium on home resale value doesn’t scale to match the investment. Smaller systems for more modest homes ($150K-$300k) actually return a much higher margin on the investment when the home hits the real estate market.

The premium buyers are willing to pay for a solar-equipped home shrinks for increasingly large PV systems. Source (p. 29)

Final Thoughts

Any way you slice it, solar is a sound investment.

If you live in your home for the duration of the warranty, you can expect a grid tie system to pay for itself 2-3 times or more in tax breaks and energy savings.

Even if you decide to move before the warranty is up, you still come out ahead. The value of the system translates directly into a higher sale price when your home hits the market. And that premium is typically enough to cover the cost of the hardware, which means homeowners break even on their solar investment right from the start.

Click to download our guide to getting started with solar power
Weighing the Pros and Cons of Tesla’s Solar Roof

Weighing the Pros and Cons of Tesla’s Solar Roof

By RICKY RAFFAINI, Tech Support Rep at Wholesale Solar​

Tesla’s Solar Roof is finally making its way to consumer homes. Ever since the product reveal nearly two years ago, people regularly ask us whether the Solar Roof is a sensible way to go solar.

We decided to weigh the pros and cons of Tesla’s latest offering to see whether it lives up to the hype.

Production of the Tesla Solar Roof has been limited, and prices are still sky high to capitalize on new release hype. We love the design, but we need to see a steep price drop – and proof the product is reliable – before we recommend it as a sound investment for the average residential consumer.

The Basics

What makes the Solar Roof unique? In a conventional setup, solar panels are housed in a dedicated module, which is then attached to a roof or installed elsewhere on your property. In contrast, Tesla’s Solar Roof is a rooftop with solar panels embedded directly into the shingles.

The solar array isn’t a separate unit installed on top of your roof – rather, it is your roof.

Tesla Solar Roof vs. a conventional solar array
Left: a solar array installed by a Wholesale Solar customer. Right: Tesla’s Solar Roof.

Each shingle is a discrete solar panel. A percentage of the panels are solar-enabled, while the rest are “decoy panels.” The non-enabled panels look exactly the same, to maintain a uniform aesthetic. Customers can determine what percentage of panels they need to enable to meet their energy needs.

Are You on the List?

Tesla loves to build hype around their products long before they hit the market, and the Solar Roof is no different. After announcing the concept in October 2016, Tesla CEO Elon Musk tested the first trial installation in his home in Q2 of 2017. (Isn’t it nice to be the boss?)

The publicity generated intense interest from consumers, who rushed to sign up on the waitlist for residential installations. It took less than three weeks after sign-ups opened for Tesla to sell out their stock through the end of 2018.

Now, we’re getting our first look at a completed installation looks like in a residential setting. YouTube channel E For Electric tracked down Tri Huynh, one of the earliest adopters of the Tesla Solar Roof, to speak with him about the installation process.

Huynh applied to install a Solar Roof for his home as soon as the announcement was made. He said it took well over a year for Tesla to contact him to conduct a site survey. After screening his eligibility, Tesla warned it would be another year for production to finish before they could proceed with the installation.

Huynh didn’t mind the wait. His home already needed a new roof, and as an early adopter of new technology, he was willing to hold out until the Solar Roof hit the market. He put down the $1000 deposit to hold his place in line.

Tesla finally met with Huynh for a site survey early this year. Two solar techs spent a day evaluating his property, even flying a drone above his house to take aerial pictures. Shortly after that, Tesla deployed a team of 20 workers to perform the install. It took about two weeks to complete, although rain added delays to the process.

The size of the workforce and install time both seem excessive to us. But the Solar Roof is a new product, and Tesla wants to get it right. We expect that process to be streamlined as they work out the kinks.

Evaluating the Pros and Cons of the Tesla Solar Roof

Tesla is a company with a certain mystique about them – people get super excited about every announcement they make. So it comes as no surprise that people constantly ask us what we think about the new Solar Roof.

We wanted to take a deep dive into what we know about the Solar Roof to help you determine whether it’s a viable option for your needs.

First, a quick summary of the pros and cons:

Pros

  • WOW FACTOR. It’s gorgeous – no blocky solar panels jutting out from your roof.
  • DURABILITY. Solar Roof panels received the highest possible hail, wind and fire resistance ratings.
  • WARRANTY. The 30-year warranty goes beyond the industry standard. There’s also a lifetime tile warranty to cover physical damage.
  • TALK OF THE TOWN. Who doesn’t love to be the first to get their hands on new tech?

Cons

  • EXPENSIVE. The Solar Roof costs about 4 times as much as a DIY solar installation, even if you hire a contractor to help. Though the former gives you a new roof, you still pay a steep premium for the Tesla brand.
  • THE WAITING GAME. The first residential customers spent over a year on the waitlist before their Solar Roof was installed.
  • UNRELIABLE. More discrete parts means more chances for hardware to fail. Past iterations of the solar shingle design were notoriously high-maintenance.
  • POOR ROI. You pay a premium for Tesla-branded roofing products, which eats into your investment.

Let’s take a deeper look.

Pros

Slick Design

First and foremost, the Solar Roof looks amazing.

It’s designed to be indistinguishable from a roof built out of traditional materials. Looking at pictures of the Solar Roof, I wouldn’t have guessed there were solar panels built into this rooftop unless you pointed it out.

Tesla will offer 4 different tile designs to match the style of your home. The panels come in textured, smooth glass, Tuscan and slate designs, which rival the appeal of their asphalt counterparts.

Tesla's Solar Roof tile designs
The tile designs for Tesla's Solar Roof, from top to bottom: textured, smooth glass, Tuscan, and slate.

Durability

Tesla claims the Solar Roof tiles are three times stronger than traditional roof tiles. This claim is backed by standards tests conducted by ANSI, ASTM and UL, which conduct standards tests for (respectively) hail, wind and fire resistance. Tesla’s tiles received the highest possible marks in all three categories.

The Envy Factor

This is the hardest to quantify, but it can also be the strongest motivator for people willing to make a huge investment into an exciting new product like this.

Before the price drops and the product becomes more widely available, it’s an awesome feeling to be part of the exclusive club that has access to cutting-edge technology before anyone else. Think of the first time you saw someone flying a drone – or driving a Tesla car on the street, for that matter. It evokes a natural sense of awe and curiosity.

The Solar Roof is no different. Huynh said that his neighbors regularly stopped by to chat during the installation, and most couldn’t resist lingering to ask questions about the newest Tesla product.

People are naturally drawn to innovation, and early adopters get a rush from riding the first wave of a new technology. As another early residential Solar Roof customer put it, “I feel like we’re living in the future!”

(Mostly) Generous Warranty

The Solar Roof is covered under a 30-year warranty for power and weatherization. The power warranty covers the output capability of the solar arrays. The weather warranty protects against failure as a result of water damage or other weather effects.

30 years eclipses the standard coverage for most solar arrays on the market, which typically offer a 25-year warranty. The extra 5 years may be a selling point to counteract the hesitation early adopters have when they invest into an unknown product. With no established track record, there’s no guarantee the product life won’t be shortened by a major design flaw down the road. The 30-year warranty may help alleviate those fears.

Tesla also offers a lifetime tile warranty, which covers physical damage to the glass in the tiles. If one of the glass panels ever breaks, even after the 30-year period, it will be covered under the lifetime warranty.

However, this doesn’t quite tell the whole story. Most traditional solar panels come with a 25-year power warranty and a 10-year workmanship warranty. If your array breaks down due to product defects, you’re covered for 10 years.

It’s not clear whether Tesla’s warranty covers the same ground:

Our tile warranty covers the glass in the tiles. The power warranty covers the output capability of the solar tiles. Weatherization means that there will be no water leaks or other weather intrusions during the warranty period that result from our installation.

-Warranty info from the Solar Roof product page

There’s no mention of a workmanship warranty, except as it relates to weather intrusions. So if your system fails due to faulty wiring, bad connectors or a broken junction box, you might end up paying for it out of pocket.

Tesla’s warranty is longer than the industry standard, but the extent of coverage may leave something to be desired.

Cons

There’s no doubt the Solar Roof is an innovative product. There’s nothing on the market that competes with it right now. That said, there are a handful of prohibitive factors that would stop us from recommending it to a majority of hopeful buyers.

Steep Up-Front Cost

Let’s get The Big One out of the way: for the Solar Roof to be financially viable, it needs to replace your existing roof. And even then, building a traditional roof with a dedicated solar array is a more efficient investment.

When Consumer Reports ran the numbers on the cost to install a Solar Roof, they estimated a typical installation might set you back $73,500 for a 3,000-square-foot roof.

Compare that to our discrete solar modules. A package for the same sized home might run one-third to one-quarter of that cost to install on your rooftop, depending on the energy output.

Even if you paid for a brand-new roof and then built a solar array on top of it, you’d come out spending much less. EnergySage estimated a 33% price premium on the Solar Roof compared to building a traditional asphalt roof + solar array.

As you can see, the majority of the installation cost of the Solar Roof comes doesn’t come from adding a solar array. It comes from building an entirely new roof, which is a much steeper investment. And Tesla hopes to upsell you on roofing costs based on their strong brand capital.

Low Return on Investment

But let’s say the stars align. You’re in the market for a brand new roof, and you’re looking to go solar as well.

Even under these ideal circumstances, the Consumer Reports analysis couldn’t conclusively state it would be a good investment.

For a two-story home in Texas, where the A/C might run 300 days a year, the $73,400 in tax credits and energy savings falls short of the $86,100 cost to install the Solar Roof. In that scenario, the homeowner would find themselves $12,700 in the hole. Even with substantial energy savings, they would actually lose money over the life of the warranty.

Things look a bit brighter for a small ranch-style home in sunny California, where energy costs are sky high. Consumer Reports estimated a $56,800 Solar Roof might earn the owner $41,800 in net savings over the life of the system.

That’s not bad, but it’s still a far cry from a traditional PV system, which can pay for itself 2-3 times over during the life of the warranty.

The premium you pay for Tesla-branded roofing materials eats into most, if not all, of the money you save from reduced energy bills. The end result is that it takes ideal circumstances just to break even on the investment.

One of the main selling points for solar is its viability as a long-term investment. It’s not uncommon to see a 200-300% return on investment out of a traditional solar array.

Since the install cost is substantially lower, the average payoff period is much shorter. Investing in a traditional solar array can net you a healthy profit in the long run.

With the Solar Roof, Tesla aims to upsell a product you don’t need (a new roof), eating away at the value of your investment into solar energy.

In terms of the time value of money, it’s crazy to invest $70,000 for 30 years to see little to no return. There are better ways to put your money to work for you.

Availability

Even if you do need a new roof, we’re operating under the assumption that the installation will even be available to you. As it stands, you’ll need the leeway to plan the installation far in advance, as people have already been on the waitlist for the Solar Roof for over a year.

If you’ve already decided you need to replace an old roof, you may not have time to wait to get started. The need to replace leaks or structural damage is likely too urgent for you to hold out on the waitlist.

Similar problems arise with the construction of a new home. If you’re working with a contractor, your build is probably on a strict timeline. Holding out for the go-ahead from Tesla might not work with permitting, your contractor’s schedule or your own target move dates. After all, you can’t move into a house with no roof because you’re waiting for Tesla to call you back.

As production of the Solar Roof ramps up, we expect the waitlist to clear, at which point these problems will disappear. For now, Tesla needs to clear through their backlog of eager customers, which may throw a wrench in your plans.

Untested Technology

We touched on this a bit in the warranty section. New technology always comes with unanticipated problems and surprises. The first version of a product never works as well as its successors. It always takes a few iterations of new technology to come out with a stable and reliable product.

The 30-year warranty does a bit to assuage these fears – if something breaks, you’ll be covered. But that doesn’t change the fact that it’s still a hassle when things break. Failures mean calls with support, appointments with technicians, and warranty paperwork to fill out. It may not cost you money, but it still adds stress and takes time out of your life.

Tesla designs great products, but every new product has some kinks to work out. A solution from a more established product line is bound to work more consistently and require less upkeep on your end.

Extra Maintenance

In addition to the stability of first-generation technology, we have concerns that the design of the Solar Roof itself could lead to extra maintenance.

Each shingle is a self-contained solar panel. That means that there are hundreds of individual panels that make up your solar array. And more parts equals more opportunities for an individual part of the system to break down.

The best-case scenario is that each part functions independently, allowing it to be replaced without affecting how the rest of your Solar Roof functions. At worst, if the parts are inter-connected, one panel going out may put a damper on the energy generation capabilities of the entire array.

There’s a precedent for these concerns. The Solar Roof is a new take on existing technology known as Building Integrated PV (BIPV). There’s a reason BIPV products fell off the market: the product was unreliable, difficult to install, and more expensive than traditional solar panels. As Green Tech Media noted, “BIPV frequently amounts to paying a premium for less of a return. That math has already killed a long line of companies.”

Until the Tesla’s new product eclipses the performance of its predecessor, we see no reason why the Solar Roof won’t suffer from the same problems that doomed BIPV.

Contractor Woes

Since the Solar Roof is a new product, it will be challenging to find a contractor capable of performing the install. Tesla is notoriously picky with who they vet to perform their labor. Even if the Solar Roof is available in your region, there’s still the additional hurdle of securing a qualified installer.

There’s another major complication with the installation process. The people who install the roof are different than the people who do the electrical work. Roofers typically aren’t electricians, and vice versa. Installing the Solar Roof will require the coordination of multiple specialized contractors.

In the past, we’ve had customers tell us they ditched Tesla over frustrations with the long waiting period and lack of available contractors to perform the install. Not only are traditional solar panels a more sound investment, navigating the installation process is more manageable than tracking down a team of Tesla-certified installers.

The Final Verdict: Should You Buy a Tesla Solar Roof?

The Tesla Solar Roof is a gorgeous product with a prohibitively high cost to install. Right now, it’s largely a premium solution for early adopters who don’t mind paying more to access cutting-edge technology in high demand. Anyone who invests in the Solar Roof should also be willing to contend with more frequent maintenance than a traditional solar array might require.

Lastly, you should be willing to wait for production to catch up to demand. Just know that you’ll be running on Tesla’s schedule, and they’re a lot better about generating hype around new products than meeting production deadlines.

Consider the Tesla Solar Roof if:

  • You have the financial means to make a substantial investment into a new roof
  • You like to get your hands on cutting-edge technology and don’t mind joining the waitlist
  • You don’t mind performing more regular maintenance on your solar panels
  • You live in a populated region with access to Tesla-certified installers

Go with a traditional solar array if:

  • You want to maximize your return on investment
  • You want the most efficient product for your money
  • Your purchase is time-sensitive
  • You’re willing to sacrifice aesthetics in exchange for functionality
  • You want a stable, market-tested product
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What’s the Best Off-Grid Solar Inverter?

What’s the Best Off-Grid Solar Inverter?

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By JOSH ROELOFS, Products Manager at Wholesale Solar

If you’ve spent any time researching solar energy, by now you’ve heard of an inverter.

The inverter is like your solar system’s brain. It manages your power flow, controlling two kinds of power.

DC—or direct current—power is the kind stored in batteries. It’s also the kind produced by solar panels.

But you can’t use DC power (directly) to power anything in your home. That’s where your inverter comes in.

Everything in your home uses AC—or alternating current—power. And an inverter takes DC power from your panels (or from batteries) and turns it into AC so it can be used for your fridge, lights, TV, and other household appliances.

Simple, right?

How IS an off-grid inverter different from a grid-tied inverter?

A grid-tied inverter takes DC power from solar panels, turns it into AC, and sends it into the grid for credit.

Grid-tied inverters are simpler and easier to wire since there are usually only two main components—the inverter itself and your solar panels. (Some grid-tied systems are starting to incorporate energy storage, but most don’t have any batteries at all.)

But an off-grid inverter needs a battery bank to function.

Here’s how it works: your solar panels feed DC power into the batteries. Then your inverter takes that power and “inverts” it, creating AC power for your home. This works essentially like a miniature power grid.

(In case you’re curious, no, your inverter won’t deplete your batteries provided your system is set up and designed right. The battery bank gets recharged by your solar panels and a charge controller, and by a backup generator in the winter months.)

As you might imagine, off-grid systems are more complicated, thanks to additional components like the charge controller, battery monitor, and additional AC and DC circuit breakers. All of these things tend to make off-grid systems more difficult to wire and install.

It can also be a challenge to buy off-grid equipment because there are a lot of associated accessories: remote controls, battery monitor, breakers and enclosures, surge suppressors, and so on.

Picking the right parts can be confusing enough—but there’s no more critical decision than buying the right inverter.

How to choose an off-grid inverter

Think About Size

The first thing to think about is how much power you need.

Fortunately, sizing off-grid inverters is straightforward if you know what appliances you’re going to use.

Add up the wattage of all your lights and appliances to calculate the number of watts you’d need if everything was used all at once. (No, you’re not likely going to use everything, but this is an easy way to be safe.)

Don’t forget to consider the voltage—although most appliances run on 120Vac, some appliances, such as well pumps, require 240Vac.

What’s the most popular size we sell? 4kW followed by 8kW. Different models and brands are available in various sizes and most of them can be stacked together for higher power output.

Consider Pure Sine Wave Instead of Modified Sine Wave

You may hear some manufactures talk about pure sine wave inverters. You don’t need to understand exactly how these work—it’s enough to know that the power that’s put out by a pure sine wave inverter is “cleaner” than what you’d get from a modified sine wave inverter.

Pure sine wave inverters deliver higher quality power output, similar to (or better than) our power grid. Modified sine wave inverters are cheaper, but they deliver lower-quality power output.

For this reason, modified sine wave inverters can cause issues with certain appliances. Motors, pumps and compressors run hotter and wear out more quickly. Certain sensitive appliances like computers can be damaged, or they may not work at all. These inverters also typically cause background noise on a stereo, and reduced video and audio quality for certain TVs.

That’s why we don’t recommend modified sine wave inverters for most applications; most of our off-grid customers are use pure sine wave inverters to avoid these potential issues.

Need a quick way to tell the difference? Look at your inverter’s total harmonic distortion (THD) rating. THD is an indicator of power quality output and will be listed on the spec sheet of any decent inverter.

Look at the Technical Specs

Here are some other technical specs to consider:

  • Efficiency. This is a measure of how much power from the batteries your inverter delivers to your home when it’s operating in perfect conditions. A good peak efficiency rating is around 94% to 96%.
  • Self-consumption, or no-load current draw. How much power will your inverter consume just sitting there? Obviously you want this to be as low as possible.
  • Surge capacity. How much short-term overload can the inverter handle before it “trips?” Some appliances, like pumps or fridges, need as much as 2x–3x their running power to start up.
  • Battery charger output. Many off-grid inverters include a battery charger, which is used to recharge your batteries during the winter months with a backup generator. The battery charger will have a rating, usually measured in amps. Most decent off-grid inverters will have a battery charger in the range of 50-100 amps DC.
  • Temperature range. Inverters are sensitive to extreme heat. Pay careful attention to the temperature range if you plan on installing your system in your garage or anywhere it could be exposed to temperature extremes.
  • Warranty. Warranties start at 1 year and typically range from 3-5 years, with a few manufacturers offering a 10 year warranty extension option.

You can normally find information on all these features on the product spec sheets. Check with your solar tech for help comparing and picking the right inverter.

Research Features

Your inverter may need special features. Look into these ones:

  • Battery charger. A charger allows your system to be charged from a backup AC generator. Most bigger inverters include this; these are called “inverter/chargers.”
  • Grid-tied capability. Some off-grid inverters have the added capability of feeding power into the grid, here are a few examples:
    • Outback FXR/VFXR
    • Outback Radian
    • Schneider XW+
    • SMA Sunny Island

    This capability is useful if the grid becomes available in the future, or if you are setting up a grid-tied system with battery backup.

  • Automatic generator start. Usually you’ll need an add-on accessory for this, although some inverters or charge controllers can take care of it.

Read Up on the Manufacturer

Knowing about the inverter manufacturer is also important. Check into their history and reputation. Off-grid inverters need to be on all day, 365 days a year, for several years at a time—so you’ll want to choose one from a manufacturer with a reputation for reliability.

In our experience, there are only a handful of companies making high quality inverters for this purpose:

Make Sure it Has UL Listings and Certifications

Off-grid inverters have a few different certifications required in the US, for safety and also to ensure code compliance.

Inverters for your home need to be UL 1741 listed. Mobile inverters for boats and RVs should carry a UL 458 certification. There are a few other requirements for different applications such as UL 1778 for uninterruptible power supplies and KKK-A-1822E standard for emergency services, such as ambulances.

There are other standards required outside of the US such as CSA 107.1 in Canada and IEEE 1547 used internationally outside of North America.

Don't Forget Price!

You also need to look at the price of the inverter system (including all required components)—as well as the features you get for that price.

Make sure to compare the price of all required components, including the remote control, circuit breakers, mounting plate, and anything else required to install the system.

Another Good Option: Using a Pre-Wired Power Center

A power center is a pre-wired off-grid inverter system that includes everything you need: an inverter, charge controller, remote control, and circuit breakers.

Most of the power centers we sell also include some additional components for monitoring and protection, including a battery monitor, and surge suppressors.

We assemble power centers with all of these components, and then wire them up and test on our workbench to make sure the system is wired correctly and working.

Buyers, especially those looking to DIY, love power centers because you can add them to a solar installation by making only a few final connections. (We even label the connection points to help make it even easier.)

So... What's the Best Off-Grid Inverter?

Your choice of inverter really depends on your size requirements and the application, but here are some of our favorites:

Our Pick For: Best Small Off-Grid Inverter

Morningstar SureSine

  • 300 watts 120Vac output
  • 12Vdc battery bank

This inverter is small. At just 300 watts of output power, it can handle lights, charging phones and tablets, and an efficient TV—and that’s about it.

But the SureSine is renowned for being extremely durable. It’s also used for industrial applications, powering remote equipment in harsh conditions all over the world.

It’s efficient, with very low self-consumption, which makes it ideal for smaller systems like a hunting cabin.

It’s also perfect for industrial remote power systems that require a small amount of 120Vac power.

Our Pick For: Best Off-Grid Inverter for Cabins & Small Homes

Magnum Energy MS-PAE

  • Two models: MS4024PAE and MS4448PAE
  • 4kW-4.4kW 120/240Vac output
  • 24-volt or 48-volt battery bank

The MS-PAE inverter series comes in two sizes: 4kW 24-volt, or 4.4kW 48-volt.

Magnum Energy inverters are fairly easy to set up and use. They have good surge capability and powerful battery chargers. They also have a nice Magnum Panel system that includes a back plate and breaker panel (to make a complete power center).

Installing these inverters on a Magnum Panel bumps up the standard warranty from three years to five.

There are accessories available, including a battery monitor, automatic generator start (AGS) and MagWeb kit for remote monitoring.
MS-PAE Magnum Power centers have been our best selling power centers for years, both for off-grid cabins and for small homes.

Multiple MS-PAE inverters can be stacked together—up to 4 inverters, or 17.6kW total—which makes this inverter also suitable for bigger off-grid homes.

The 4kW 24-volt model can work with smaller battery banks and solar arrays; that’s ideal for cabins.

Magnum inverters are available in a wide range of sizes, and they are relatively affordable and easy to set up, which makes them a great choice for off-grid cabins and homes.

Our Pick For: Best Large Off-Grid Inverter

Schneider Electric XW+

The XW+ inverter comes in two sizes: 5.5kW or 6.8kW output power. Both work with a 48-volt battery bank.

Multiple inverters can be stacked together, and groups of three can be combined for three-phase power systems.

Schneider offers several accessories including a power distribution panel, automatic generator start, and battery monitor. The Schneider XW+ system really excels with bigger, multi-inverter systems.

Schneider supports multiple clusters of inverters for large industrial and commercial applications, up to 102kW output power. They also support Lithium batteries.

All of these features, plus the ability to stack clusters of inverters, make the XW+ our choice for large off-grid power requirements.

BONUS PICK! Best Inverter for Grid-Tied Systems with Battery Backup

Outback Power Radian

The Outback Radian is an off-grid inverter that can also tie into the grid to sell your excess power.

This is the ideal option if you want the combination of battery backup and grid-tied solar, or if you’re off-grid but you think access to the grid will become available in the future.

The Radian inverter system includes advanced software, called Optics RE, for remote monitoring and control, allowing you to monitor your system, get alerts about any faults, and change settings remotely. It can also control generators for basic automatic start and stop.

Currently this is the only battery-based inverter approved for grid-tied interconnection throughout the US. It’s also the only grid-tied battery backup inverter available that complies with the newest standards in CA and HI for connecting grid-tied systems.

It’s available in two sizes, 4kW or 8kW, and multiple inverters can be stacked together for up to 80kW of power.

This is our best selling inverter for grid-tied with battery backup; most customers opt for either one or two of the 8kW inverters (either 8kW or 16kW.)

Click to download our guide to getting started with solar power
SunPower Buys SolarWorld, Reviving An American Solar Giant

SunPower Buys SolarWorld, Reviving An American Solar Giant

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By COURTNEY JOHNSTON, Purchasing Manager at Wholesale Solar​

America’s largest solar manufacturer is teaming up with a leading technological innovator in the field.

SunPower announced this morning that it will acquire SolarWorld Americas for an undisclosed sum. SunPower will take over operation of SolarWorld’s manufacturing facility in Hillsboro, OR. The deal gives the largest American solar manufacturer the backing of one of the industry’s leading technological innovators. It should help both companies stay competitive and keep prices down for consumers.

With the acquisition, SunPower hopes to avoid the tariff on solar imports imposed in February. Under the tariff, foreign manufacturers pay a 30% tax on cells and modules imported to the United States for sale.

Silicon Valley is home to SunPower headquarters. But they outsource their manufacturing to Southeast Asia and Mexico. That will change when this deal finalizes. SunPower plans to assemble their low-cost P-Series module at the newly-acquired Oregon plant. Shifting manufacturing efforts into the U.S. effectively bypasses the tariff.

This move seems to be a savvy way for SunPower to remain competitive in the American market. Most solar companies will opt to raise prices to offset increased import costs. Instead, SunPower will plug into SolarWorld’s established manufacturing and distribution infrastructure. This should soften the impact of the tariff and keep their prices affordable.

The result for consumers? A technological leader joins forces with an experienced American manufacturer. This deal helps both SunPower and SolarWorld stay competitive. We expect any pricing changes on their product lines to be negligible.

A Win-Win Deal

The deal is a major victory for SolarWorld. They’ve been around for over 40 years and have proven to be the most resilient solar brand in America. But their growth has not come without its rough patches.

SolarWorld’s German parent company, SolarWorld AG, filed for bankruptcy in 2017. Since then, SolarWorld Americas trimmed their workforce and cut back research and development.

As a result, SolarWorld has struggled to compete with the cheap import market. Last year, they joined Suniva to lobby for the tariff which was eventually enacted this February. Ironically, that same tariff drove SunPower to seek American manufacturing options.

The SunPower acquisition provides much-needed relief to help them stabilize. SunPower has pledged to invest capital to reignite SolarWorld’s R&D efforts. SunPower will also fund improvements for the Oregon manufacturing facility.

The partnership is ideal for SolarWorld. SunPower is a technological leader in the solar industry. Their premium modules are among the most efficient products on the market. The new investment capital and guidance of a market leader bodes well for SolarWorld. We’re excited to see what innovations will come to their products in the near future.

The Oregon facility SunPower inherits will also continue to produce SolarWorld-branded legacy products. That’s great news. SolarWorld’s longevity as an American manufacturer has earned them a loyal following. We want to see their full product line remain on the market.

SolarWorld’s CEO, Jürgen Stein, commented on the impact the deal will have on his company’s operations:

“We are delighted that SunPower has agreed to inject fresh capital and their industry leading P-Series technology into SolarWorld Americas operations here in Hillsboro. Our hundreds of long-time employees are excited to be part of this next chapter in SolarWorld Americas’ long history. We are thrilled about this acquisition as it means quite simply, that our company can look forward to redoubled strength as it continues to innovate and expand into the future. This outcome is ideal for SolarWorld Americas and its employees.”

Wall Street seems to agree that this is a strong move for SunPower. SPWR opened at $8.81 on Wednesday, the day news of the acquisition went public. The stock continues to rise a day later, peaking at $9.77 a share at the time of publication.

The acquisition is not final until U.S. and German trade officials approve it. SunPower expects the deal to become official by the end of June.