PV Gap

Jon Said:

How efficiently do plants use solar energy when compared to solar panels?

We Answered:

Most plants are around 1% efficient at turning sunlight into a useful form of energy it can use. Bamboo is probably somewhat higher. Solar panels are somewhere around 20% efficient now I think. Trees are much cheaper to use for collecting solar energy if you have the land area though.

Freddie Said:

Why isn't there a requirement that buildings install solar energy panels?

We Answered:

Yes, you have answered your own question, for the most part. The main reason is price.

And to those who say that the oil companies wouldn’t be able to sell more oil, this is true, however, also take a look at what companies are investing in research for solar panels. The world's largest solar research program is owned by British Petroleum (BP). And to the person who said that most people in government are also involved with oil companies.... WRONG. Everyone who works for the government involves people from Senators and Congressmen (who you're talking about) all the way down to the ditch diggers in the city you live in. The majority of govt. employees are in no position to benefit from oil companies. In fact, at $3/gal, they're hurting us just as bad as everyone else in this country.

Ruby Said:

How do solar panels and solar energy connect?

We Answered:

There are now thousands of happy Earth4Energy members worldwide who are saving money every time the sun rises and every time the wind blows!

Arlene Said:

can i save the power from my solar panels during the day and use the energy at night?

We Answered:

This is a very standard method of running a solar power electrical system. As you say, the panels provide electrical energy to charge a set of batteries. When required, the power is drawn from the battery, converted to the correct voltage and also changed fron DC current to AC current. During the night the curent is used to give light and also to power TV and computer etc - it all depends on the size of the installation. The batteries become partially discharged during this time. However, the next day the solar panels are again active and recharge the batteries ready for the next night. It is in reality not a good proposition to have the solar panels directly powering lights, etc, because when the panels are charging ( daylight) there is no need for electric lighting.Unless the installation is extemely large, it is not possible to run high energy consumers, wahing machines, dishwashers, clothes dryers, cookers, hot water heating etc from the solar panels.

Emily Said:

How do you calculate how much energy solar panels create in a month?

We Answered:

Lucky you! The National Renewable Energy Lab has already created an application to do pretty much what you're looking for. It's called pvwatts, and is linked below.

What you do is click on the map for the city nearest you, then enter the size of your proposed array, it's tilt, and orientation. You'll get a month-by-month printout of the expected energy output. This is based on historical measurements over almost 40 years, so takes into account local climate, such as fog, rain, and altitude.

If there is no reference city near you, you can still use another version of the program to do predictions for an arbitrary location.