PV Gap

Robin Said:

Do solar panels produce more electricity in stronger sunlight?

We Answered:

Sunlight "strength" is not a physical property. If by stronger sunlight, you mean the shortest distance between your solar panel and the sun over the course of a day, then yes. Photovoltaic cells can have multiple junctions that allow for varying wavelengths of light to penetrate the layers of the panel and generate a direct current. When the sun is directly above you, you will be exposed to as many wavelengths as are available to make your PV cell generate current. When the sun is setting, the sky is red. That means only longer wavelengths are getting to your solar panel and it doesn't work as well if it's been designed to receive short wavelengths.

Tammy Said:

How do solar panels convert the Sun's energy into electricity?

We Answered:

To put it simply, photons from the sun strike the Photo-voltaic panel and cause electrons to start moving which creates a DC current.This DC current can then be converted to AC by way of an inverter. Here is a good
article I found:http://science.howstuffworks.com/solar-c…
It is pretty good reading if you are interested in Solar.

Marian Said:

Does anybody here have solar panels and sell the extra electricity to the power company?

We Answered:

The answer depends on a lot of things.

1) In the US, any public utility company is required to buy back your excess power. Some small companies, like Co-ops and municipal companies, are except from this requirement. However, there is no regulation about how much they have to buy it for. Some companies buy it back at the same rate they sell it. So if you sell 500kwh a month, and buy 500kwh a month, your bill would be $0 (or a small connection fee). Some pay you an "avoided cost" rate, what they buy from other power plants, at a fraction of what they sell it for. So you may buy it at $0.15 per kwh, but they'll buy any extra from you for $0.05. Some companies limit you to zeroing out your bill, some will write you a check for whatever you generate.

2) How much power you use would determine how big of a system you need. If you buy 1000kwh per month, you would need a system big enough to generate that much during the day, so you can sell the excess during the day, and buy it back at night. That way, you don't need batteries for night, you basically use the electric company to hold your extra power until you need it later. Check out how many kwh you buy a month from the electric company, it will be listed on your electric bill. Plug that number into the calculator at http://www.altestore.com/store/calculato… That will tell you how big of a system you need.

You know the expression it takes money to make money? It will cost a lot to buy a system bigger than what you need, and with few exceptions, will most likely not make you money selling power back. It's a better investment to first spend your money on conserving electricity, it costs less money to save electricity than to make it. Once you have cut your requirements, THEN look into buying a solar system.

Most people buy a system big enough to generate a percentage of what they use, therefore reducing their bill, not eliminating it, and certainly not making money on it. Many tax incentives are available to help pay for it, you can see them at http://www.dsireusa.org.

The AltE Store has got some great free videos talking about solar power, check them out at http://www.altestore.com/store/Books-Cla…