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Is a solar electric system right for your home?
Have you heard the buzz about the incentives for installing solar power systems, but weren’t sure how this technology could work for you? One of the most common ways is to use solar energy to generate electricity for your home with a photovoltaic (PV) system. The following tips and resources on PV systems, compiled with information from the US Department of Energy (DOE), can get you started.
WHY CHOOSE A SOLAR ELECTRIC SYSTEM?
It reduces environmental harm. By converting sunlight directly into electricity without any air pollution, solar PV electricity systems reduce your consumption of fossil fuels, which contributes to smog and climate change.
It increases energy independence and reliability. All solar PV systems are powered by sunlight, so the energy they provide comes directly into your home through your solar PV system. A solar PV system can produce all or a portion of your electricity, and may or may not be connected to the utility grid.
It can save you money in the long run. The savings and potential credits on your electricity bills will be immediate. However, since the initial investment can be significant, the payback time to recover the cost of the solar PV system equipment can take years. To learn more, see our section on “savings” below.
It’s built to last. Solar PV systems were originally developed to power satellites in space and were built to be highly durable, even in severe weather. According to the DOE, typical systems may last 30 years with minimal, but routine, periodic maintenance. Many systems also come with warranties.
WHAT YOU NEED TO GET STARTED
Direct sunlight. Solar PV systems function best where the sun’s energy is strongest, such as in the southwestern U.S., but the sunlight across the country is considered ample. No matter where you live, systems can be optimized to capture the most sunlight possible, provided there aren’t any major obstructions. Ideally, solar PV materials should face south, but those that face east and west may also suffice.
Adequate space. According to the DOE, most residential systems require between 50 and 1,000 square feet of roof space, depending on how much electricity you plan to generate; typically, the more electricity that’s to be generated, the more solar PV materials you’ll need. But the efficiency of the PV module also matters; if you use very efficient (and typically more expensive) materials, you can get by with less space. You may also be able to reduce the size of your system by taking steps to make your household more energy-efficient; visit our Household energy page for tips on saving energy. It’s also possible to install solar PV panels on the ground or on structures that double as window awnings for example. Other types of solar PV materials include shingles, but these are more expensive and not yet widely available.
Your local system supplier can help you to make these evaluations by performing a solar site analysis, or guide you in carrying out your own.
THE TWO MAIN TYPES OF SYSTEMS
Grid-connected. A typical grid-connected solar PV system is hooked up to your local utility provider; that way you can receive back-up power from the grid when your system doesn’t produce enough for your needs. You can also use a battery to store excess power in case the grid goes down. When your system produces excess power, that electricity can be fed back into the grid, and your utility may be required to buy it from you. To learn more, see our section on “savings” below.
Off the grid. A solar PV system can also be set up as a stand-alone system, independent of a utility grid. The electricity is provided by solar power alone and stored in a battery for later use when your system is not producing any. Such systems typically make sense in remote locations, but can also be used by people who live near the grid who wish to be entirely dependent on solar-powered electricity.
THE BOTTOM LINE: COSTS AND SAVINGS
Costs. While the cost of solar PV systems continues to fall and incentives are on the rise, the systems still require a relatively large investment. The cost depends primarily on the size of the system (which, in turn, depends on how much electricity you want to generate) and typically ranges from about $16,000 to $40,000 before rebates, according to the DOE. You may be able to reduce your cost by taking steps to make your household more energy-efficient, which would allow you to make do with a smaller system. Visit our Household energy page for tips on saving energy.
Your roof should also be in good condition; if you have to replace your roof after installing the solar PV materials, you face the added expense of removing and replacing them.
Savings. The federal and state governments offer homeowners several incentives that can significantly offset the cost of a solar PV system. Many states provide rebates, tax incentives, low-interest loans and/or net metering—which requires your utility to purchase excess electricity generated by your solar PV system. To learn more about these incentives, visit the Database for State Incentives for Renewable Energy. There are also federal tax incentives being offered through the end of 2006; the Energy Policy Act of 2005 allows a tax credit of up to $2,000 if the system goes into service between Jan. 1, 2006 and December 31, 2007. You can learn more about these incentives through the Solar Energy Industries Association.
You can also get a better idea of the cost and savings of a system tailored for your home using The Solar Estimator, an online calculator offered by the DOE and the solar industry.
DO IT YOURSELF OR HIRE A PRO?
While some people install solar PV systems on their own, the systems are fairly complicated and the DOE recommends hiring a reputable professional contractor to avoid complications or injury. An installer will provide you with an analysis of your site and make recommendations on how a solar PV system could work best for your home. It often makes sense to get more than one assessment for comparison purposes. To find a solar installer in your area, visit the Solar Yellow Pages, a free guide offered by the DOE and the solar industry. For additional assurance, you can also search the list of installers certified by the North American Board of Certified Energy Practitioners.
Note that each state and community has its own set of codes and regulations that need to be followed in putting in a solar system. These regulations may affect the type of system you can install and who installs it. For more information, contact your regional or state energy office or visit the DOE’s local codes and requirements page.
ENVIRONMENTAL HEALTH AND SAFETY CONSIDERATIONS
Manufacturing. The main risk posed by the solar PV industry is to the safety of workers who manufacture the PV materials, a process that can involve hazardous solvents, potentially toxic or explosive gases, and the possibility of inhaling dust. The most common solar PV materials also use cadmium , a recognized carcinogen, which workers may be exposed to if they aren’t properly protected. Fossil fuel energy is also used to manufacture and transport the solar PV materials, but, according to the DOE, the benefits of using solar energy far outweigh the costs.
Use. There is little cause for concern for the homeowner. The cadmium in PV panels is in a stable form and encased in the panel, according to the DOE’s National Renewable Energy Laboratory (NREL).
Disposal. Because solar PV systems are both a new and long-lasting technology, disposal isn’t a major issue yet. Eventually, however, proper disposal and recycling systems will need to be put into place.
RELATED LINKS
Grist: Q & A On installing solar power 6/07
Grist: Q & A On solar funding 6/07
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