Evaluate Your Energy Use
The first step to designing your new renewable energy system is evaluating your current power use.
- Start by locating your Kilowatt Hour (kWh) Usage for twelve consecutive months. You can see if your utility company has this information available online, give them a call, or look at past utility bills.
- Find the average kWh Usage by adding up the kWh for each month and divide that by 12. Make a note of which months you use the most energy.
- Write this number down. You'll use it in Step Three.
Your average kWh per month will help determine what the size of your solar electric system will be.
If cost is not an issue, or if you are already saving energy with a sustainable green lifestyle, you can skip the information below and move to Step 2: Decide What Kind of System You Need.
Lower Your Current Energy UseFurther evaluation of your current energy use may reveal exactly where you can be more energy and cost efficient, ultimately making the best use of your solar PV system. See our pie chart and power consumption table for typical household percentages and hourly watts of individual appliances, lights and other electrical equipment. See how to calculate daily energy use with our Load Evaluation Worksheet and the refrigerator example on the right.
A helpful and simple way to see exactly where you can cut costs and reduce usage is with an inexpensive but sophisticated home energy monitor device like the Neurio. It uses a small meter installed on your home's energy panel to transmit data to your wifi network, and combined with the included Neurio app you can get detailed energy use data wherever you are.
Your utility or local government programs may be a great resource for your energy saving plan (and cost saving incentives). They may have free or low cost programs for evaluating your energy use and where your home may be loosing energy through ducting, walls and windows, etc. Some of these programs may have websites than can help you keep track of your energy consumption on an ongoing basis as well.
You may want to take advantage of 'Smart Home' computer programs or companies. Some programs are set up to alert you when an appliance or zone of your home is using more electricity than it should. These energy management technologies can be as simple as using a cost effective and simple app like Neurio that allows you to monitor your appliances from anywhere, to highly sophisticated (though often expensive) whole house control and automation.
Reduce Phantom Loads
Phantom loads refer to when appliances continue to draw electricity when they are "off" or in the "standby" position. They can draw electricity 24 hours a day, and some appliances draw close to full power just to be on standby. Common examples include:
- Glow bars in gas ovens
- Electronic phones
- Anything with a small "box" on the power cord
Energy Efficient Lighting
Besides changing all of your bulbs, there are other things you can do. Use daylight for reading, working and living. Low wattage task lighting can replace high-energy general overheads. Lighter colors on the walls reflect more light, and solar tubes or skylights can be an added improvement to darker areas.
New higher efficiency standards for light bulbs were put into law through the Energy Independence and Security Act of 2007 (EISA) and became effective nationwide January 1, 2012. Most bulbs are required to be 25% more efficient by using less energy in watts to produce the same amount of light, measured in lumens.
New Energy Star labeling will show lumens, estimated yearly cost, expected life, color, and watts. Look at the lumens for the brightness you want, and watts for the amount of energy that is used. This will ultimately make it easier to choose between types of bulbs.
The traditional 100-watt incandescent bulb is being replaced by a 72-watt incandescent halogen bulb, which emits about 1,600 to 1,700 lumens. Compact fluorescent bulbs that emit the same lumens only use 23 watts. While the more efficient incandescent bulbs are less expensive, the energy savings of compact fluorescent or LED bulbs more than pay for initial higher costs.
Compact fluorescent bulbs will typically save $3/year per replaced bulb (when used 4-6 hours per day). CFL bulbs can last up to 10 times longer than conventional incandescent bulbs.
LED (light-emitting diode) bulbs provide an optimal light color that is equal to or better than incandescent. LED bulbs are more durable and will not break as easily as incandescent or CFL bulbs. LED is initially more expensive than CFL but can last up to 5 times longer than CFL.
Both CFLs and LEDs use about 75 percent less energy than incandescent bulbs, without sacrificing any light. They also generate very little heat. Look for Energy Star rated bulbs for the best warranties and longest lasting lights. For instance, in about a year, lower quality LEDs can become dim and uneven, flicker, shift in color, or continue to use power when turned off, among other issues.
How to Cut Heating Costs
1. Insulation - One of the most cost-effective ways to make your home more energy efficient and comfortable is to add insulation. An under insulated attic may be the largest source of energy loss as heat rises up and through the ceiling, into and out of the attic. Walls are the second place heat looks to escape, especially in older homes where insulation could be worn or settled, or simply not insulated. Insulated window blinds or curtains can also help contain heat at night. Remember even double pane windows have very little insulative value. Click here for more information about how to use insulation with passive solar.
2. Seal air leaks. Sealing air leaks to keep the cold air out by adding storm windows or caulking gaps around the outside of windows will stop the draft from entering your insulated home.
3. Use setback thermostats. These can be installed and programmed to lower household temperatures according to your needs. You can also manually setback your thermostat. By lowering room temperatures by five degrees for an eight to twelve hour period, you can save five percent on your heating bill.
4. Use passive solar techniques. Passive Solar techniques capture the sun's energy to warm your home and avoid capture of the same energy when it is necessary to keep the house cool. House design that takes into account the changing angle of the sun, from winter to summer, can dramatically lower your energy costs.
Lower Water Heating Costs
Water heating is a major energy expense in a home. It usually accounts for 13% of your utility bill. There are six ways to reduce your water heating energy consumption:
1. Insulate the water heater. You can save money by wrapping your gas or electric hot water heater in an insulative jacket. Wraps are readily available at hardware stores and can be installed by the homeowner.
2. Lower water heater thermostat. Lower the thermostat to 110 degrees F, to optimize efficiency. And if you have an electric water heater, a timer can be installed to regulate heating cycles.
3. Insulate pipes. Too much heat is lost from the pipes coming directly from the hot water heater, and even more is lost in unheated crawl spaces. Pipe insulation greatly reduces heat loss in these areas. Users will spend less time waiting for hot water at the tap, and it will lead to less waste. On demand hot water circulation is an exciting innovation in this area and can maximize efficiency.
4. Install aerators at the faucets. These reduce hot and cold water flow while maintaining the original water pressure.
5. Install low flow showerheads. These help reduce water use by up to 50 percent.
6. Use less hot water. The 15 percent of energy that used to heat water in an average home can be lowered considerably by using a simple formula of insulating and conserving. By maximizing household efficiency, you will save.