PV Gap

David Said:

What percent is solar energy compared to all the other Electrical souces?

We Answered:

All sources of alternative energy accounts for 9% of the US Electrical use.

Take a look at the flowchart on this link. It gives you an easy way to follow the money, or rather the energy.

Tamara Said:

where are all the places that solar energy go?

We Answered:

About 15 percent of the sun's energy that hits the earth is reflected back into space. Another 30 percent is used to evaporate water, which, lifted into the atmosphere, produces rainfall. Solar energy also is absorbed by plants, the land, and the oceans. The rest could be used to supply our energy needs.

Brett Said:

according to my book, plants use solar energy with the help of chlorophyll to combine CO2 and H2O to make .?

We Answered:

Basicly, photosynthesis is the process in which a plant uses the energy from the sun to combine CO2 (carbon dioxide) and H2O (water).

This process is pretty complicated, and I am not sure what level you are, but I will give it a try.

When you try to combine CO2 (component in air) and water, nothing will happen by itself. Only a specialized reaction can make glucose (sugars) out of these 2 components.

First, a plant will capture the energy from the sun in a green compound called chlorophyll. This is the stuff that gives plants their green color. It can absorb sunlight, similar to a stone that captures the heat of the sun and radiates it when the sun is gone.

The energy is then used by the plant to "fuse" water and carbon dioxide in a set of reactions called the Calvin Cycle. Basicly, it "grabs" the carbon molecule from the CO2, and fuses it with the water molecule to make the sugars. The sugars than can be used by the plant as the basis of a lot more chemical reactions.

Pretty complex, those reactions, but I hope you get a better idea now.