PV Gap

Karen Said:

how can solar energy be used as alternate source of energy ?

We Answered:

http://www.darvill.clara.net/altenerg/so…

This is a favorite source of future energy for many people, comforted by the thought that it is unlimited. But, quite the contrary is true. The Sun will exist for a long time, but at any given place on the Earth's surface the amount of sunlight received is limited--only so much is received. And at night, or with overcast skies, or in high latitudes where winter days are short and for months there may be no daylight at all, the sunlight received is very limited at times. Direct conversion of sunlight to electricity by solar cells is a promising field, but the amount of electricity that can be generated by that method is not great compared with demand. The conversion efficiency is low, about 12 percent with present technology.

Solar energy in quantity requires huge installations. It has been estimated that an area of 60 square miles in relatively clear central Oregon would have to be covered with solar cells in order to meet the present electric needs of that State. About 10% of the cells have to be replaced each year. But the big problem is how to store significant amounts of electricity when the Sun is not available to produce it. That problem remains unsolved. The statement that "solar energy will not make next century's electricity" is probably right. And the end product is electricity--a very limited replacement for oil.

Juanita Said:

How can schools conserve energy?

We Answered:

Opening windows instead of air conditioners.
Replace traditional incandescent bulbs with compact fluorescent light bulbs.
Don't use lights at all. How about relying on natural sunlight for light?
Recycle paper. Print tests on the back of used paper.
Plant more trees. This reduces the carbon dioxide in the air.