Solar Electric

A PV system that is designed, installed, and maintained well will operate for more than 20 years. The basic PV module (interconnected, enclosed panel of PV cells) has no moving parts and can last more than 30 years. The best way to ensure and extend the life and effectiveness of your PV system is by having it installed and maintained properly.

Experience has shown that most problems occur because of poor or sloppy system installation. Failed connections, insufficient wire size, components not rated for dc application, and so on, are the main culprits. The next most common cause of problems is the failure of the electronic parts in the balance of systems (BOS): the controller, inverter, and protection components. Batteries fail quickly if they're used outside their operating specification. For most applications (uses), batteries should be fully recharged shortly after use. In many PV systems, batteries are discharged AND recharged slowly, perhaps over a period of days or weeks. Some batteries quickly fail under these conditions. Be sure the batteries specified for your system are appropriate for the application.

A 10% efficient PV system in most areas of the United States will generate about 180 kilowatt-hours per square meter. A PV system rated at 1 kilowatt will produce about 1800 kilowatt-hours a year. Most PV panels are warranted to last 20 years or more (perhaps as many as 30 years) and to degrade (lose efficiency) at a rate of less than 1% per year. Under these conditions, a PV system could generate close to 36,000 kilowatt-hours of electricity over 20 years and close to 54,000 kilowatt-hours over 30 years. This means that a PV system generates more than $10,000 worth of electricity over 30 years.

A photovoltaic (PV) system needs unobstructed access to the sun's rays for most or all of the day. Climate is not really a concern, because PV systems are relatively unaffected by severe weather. In fact, some PV modules actually work better in colder weather. Most PV modules are angled to catch the sun's rays, so any snow that collects on them usually melts quickly. There is thus enough sunlight to make solar energy systems useful and effective nearly everywhere in the United States.

Even hail won't harm most PV systems. Most homes have adequate roof space for a PV system, but you will have to size your system first to discover how much space is required. If you don't have adequate roof space, look at other options such as integrating the system into a wall or putting the system in the backyard. You could also use the system to cover a porch or patio in the backyard or mount the system on the roof or wall of a garage. Remember: an energy-efficient building requires a smaller PV system.

The size of solar system you need depends on several factors such as how much electricity or hot water or space heat you use, how much sunshine is available where you are, the size of your roof, and how much you're willing to invest.

People decide to buy solar energy systems for a variety of reasons. For example, some individuals buy solar products to preserve the Earth's finite fossil-fuel resources and to reduce air pollution. Others would rather spend their money on an energy-producing improvement to their property than send their money to a utility. Some people like the security of reducing the amount of electricity they buy from their utility, because it makes them less vulnerable to future increases in the price of electricity.

If it's designed correctly, a solar system might be able to provide power during a utility power outage, thereby adding power reliability to your home. Finally, some individuals live in areas where the cost of extending power lines to their home is more expensive than buying a solar energy system.

Unfortunately, there is no single or simple answer. But a solar rebate and other incentives can reduce the cost of a PV system. This cost depends on a number of factors, such as whether it is a stand-alone system or is integrated into the building design, the size of the system, and the particular system manufacturer, retailer, and installer. For solar water heaters and space heaters, you also have to consider the price of the fuel used to back up the system. In most cases, you would have to add the cost of natural gas or electricity to get a more accurate estimate of how much you can expect to pay for a solar energy system.

It is also difficult to say how much you will save with a solar energy system, because savings depend on how much you pay your utility for electricity or natural gas, and how much your utility will pay you for any excess power that you generate with your solar system. You can ask us how much your new system will produce on an annual basis and compare that number to your annual electricity or hot water demand to get an idea of how much you will save.

A variety of state and local incentives are available, as noted below.

To learn more about energy saving tips and renewable energy technologies, please visit U. S. Department of Energy's Energy Saver's Web site

To learn more about financial incentives in your area, please visit the Database of State Incentives for Renewable Energy (DSIRE) and contact your State's Energy Office One caveat: any time you work with a contractor, it is wise to check references.

Your U.S. Department of Energy (DOE) regional support office may also be able to provide guidance.

Net metering is a policy that allows homeowners to receive the full retail value for the electricity that their solar energy system produces. The term net metering refers to the method of accounting for the photovoltaic (PV) system's electricity production. Net metering allows homeowners with PV systems to use any excess electricity they produce to offset their electric bill. As the homeowner's PV system produces electricity, the kilowatts are first used for any electric appliances in the home. If the PV system produces more electricity than the homeowner needs, the extra kilowatts are fed into the utility grid. Currently, more than 30 states have metering programs across the United States.

Yes. Consider using a home equity loan for the purchase and installation costs of a solar photovoltaic or solar hot water system to take full advantage of federal tax deductions. Solar energy systems are viewed as a major home energy savings upgrade and there are financial tools out there that reward you for your efforts. Remember, installing a solar energy system is comparable to any other upgrade you might do to your home, such as installing a new deck or remodeling a kitchen.