FAQ

Click on a question to see the answer down the page.

Q:Why is solar energy important?
Q:How do solar cells work?
Q:How efficient are current solar cells?
Q:Are there any federal incentives?
Q:Are there any state incentives?
Q:What happens when it snows. Will my solar panels still work?
Q:How many solar panels would I need to completely power my house or apartment?
Q:Does it make sense to install a solar system if we are moving in a couple of years?
Q:When it is cloudy or foggy, will my solar electric system still work?
Q:Can you put solar on a flat roof?
Q:Is the weight too much for my roof?
Q:How long does it take to install a solar electric system?
Q:Do I need to clean the panels periodically?

Q: Why is solar energy important?

A: Solar energy is the ultimate renewable energy. Clean, plentiful and thanks to today’s technologies, easy to harvest. Every single day enough solar energy strikes the planet to meet the world’s energy needs for four to five years. In an era where global warming and CO2 buildup are of critical concern, solar energy can become an incredibly valuable solution for helping to protect our planet.

Q: How do solar cells work?

A: A solar cell, sometimes called a photovoltaic cell, is a device that converts light energy into electrical energy. A single solar cell creates a very small amount of energy (about .6 volts DC) so they are usually grouped together in an integrated electrical panel called a solar panel. Sunlight is a somewhat diffuse form of energy and only a portion of the light captured by a solar cell is converted into electricity.

Q: How efficient are current solar cells?

A: The current generation of solar cells convert only 12 to 15 per cent of the sun’s light into electricity. However in recent years there have been significant advances in their design. Some new cells on the market now are around 20% efficient and some laboratory prototypes are reaching as high as 30 per cent. Given this it is likely that their efficiency will continue to improve over time.

Q: Are there any federal incentives?

A: Beginning in 2005 congress provided strong support for solar by passing new tax credits, the biggest set of incentives on solar energy since the Carter administration. These energy incentives came from the Energy Policy Act (H.R. 6, Sec. 1335). They establish a 30% tax credit up to $2,000 for the purchase and installation of residential solar electric and solar water heating. An individual can take both a 30% credit up to the $2,000 cap for a photovoltaic system and a 30% credit up to a separate $2,000 cap for a solar water heating system. A 30% tax credit up to $500 per 0.5 kilowatt (kW) is also available for fuels cells.

Q: Are there any federal incentives?

A: The majority of state governments provide some type of incentive for solar energy. The best source for getting information on incentives in your state is a national database of energy incentives and regulations being maintained by the North Carolina Solar Center and the Interstate Renewable Energy Council (IREC) funded by the U.S. Department of Energy.

Q: What happens when it snows. Will my solar panels still work?

A: Yes. Sunlight will penetrate a thin layer of snow and the snow will usually melt fairly quickly off of solar panels. If you have had a heavy snow you can help it along by using a squeegee on a pole to scrape off the surface layer of snow.

Q: How many solar electric panels would I need to completely power my house or apartment?

A: The obvious answer of course is it depends on how much energy you use. Another big factor is whether or not you are trying to supplement your energy supply with a grid-tied system or if you are off the grid and trying to cover all of your energy needs. Probably the easiest way to look at it is to consider a range based on the amount of roof space you have available for placing the solar panels. An installation with about 14 panels would probably provide about 40-%-50% of your energy needs. If you have a large roof area you can probably fit about 24, 125 watt solar panels and cover 75%-100% of your energy needs. If your roof is not south facing or if it is partially shaded the energy output will be somewhat lower. A reputable solar installer can help you determine what is practical for your home and the amount of power you can practically generate from the space you have.

Q: Does it make sense to install a solar system if we are moving in a couple of years?

A: Probably. Most real estate experts currently believe that given the concerns about energy costs a solar system will significantly raise a home’s value. One source, the Appraisal Journal, states that the value of your home is increased by $20 for every $1 reduction in annual operating costs resulting from installed energy efficiency measures or energy generation systems. However, this very much depends upon the local market so you should probably confirm this with an experienced local real estate agent before making this decision if you know you are planning to sell in a relatively short period of time.

Q: When it is cloudy or foggy, will my solar electric system still work?

A: Yes. The solar electric system will continue to operate under fog or cloud cover but its output will be reduced. The solar electric system’s power output is relative to the “depth” of the cloud cover and how much light gets in, but typical coastal fog only reduces power output by 50%. Winter storm clouds will cause substantially greater reduction but the system will still produce energy.

Q: Can you put solar on a flat roof?

A: Yes. Most commercial solar electric systems are installed on flat roofs. The solar panels are usually mounted on “tilt-racks” which put the panels at the optimum angle and face them in the right direction.

Q: Is the weight too much for my roof?

A: No, solar modules are very lightweight. The combined weight of the rails and solar modules is only 3 lbs per square foot.

Q: How long does it take to install a solar electric system?

A: Solar electric systems usually take between two to five days to install, depending on the size and complexity of your solar electric system. However, in our experience the actual calendar time is usually longer because there are often delays waiting for the local energy company to install the electrical meter (in a grid-tied system) or waiting for local electrical inspectors.

Q: Do I need to clean the panels periodically?

A: In most areas of the country, there is sufficient rain to clean the panels. However, if you are in a dusty area (very near a busy dirt road, very urban area, etc.) you may see a performance gain from cleaning the panels monthly. If necessary, a hose stream is usually sufficient for cleaning. Do not walk on or over the panels to clean them. Do not use metal, hard, or abrasive methods for cleaning. Do not spray water on the panels when they are very hot.