How efficient is solar energy compard to other energies?

Question

How efficient is solar energy compard to other energies?

Answer 1

Solar and wind have to be better than fossil fuels!!

Answer 2

There is no way in h**l that we could ever use all the energy of the sun. There will always be trillions of gigawatts that any device we put in place will not capture.

Now if you are looking for percentage of incident radiation on the area of the collector, we get about 10% +/- 6%.

If you are going for percentage of rated capacity, on a 24 hour basis we get about 34% of rated capacity at best.

A gasoline or diesel engine can get close to 35% of the energy equivalent of the fuel, but may be able to deliver close to 70% of its rated maximum capacity on a sustained basis.

A nuclear rector may put out 100% of its rated capacity, but will derive only a small fraction of the amount of energy this amount of fuel could theoretically deliver, based on use in a fusion reactor.    

Gas turbines may deliver 30 to 50% of the power the fuel should have, but a full 100% of rated capacity.

Thermal steam engines may give close to 50% of energy in the fuel and often exceed rated capacity.

Now, efficiency means different things, and we have great difficulty making fair comparisons, difficulty deciding what matters.

Answer 3

I'd like to echo Don's point.

Photovoltaic solar panels are not very "efficient" in that they only collect about 10% to 15% of the solar energy that hits them.  But since that supply of energy is both limitless (assuming no space constraints) and free, it really doesn't matter too much how "efficient" they are.  

The reason we care about energy efficiency is when there is some cost to the fuel.

Answer 4

Solar energy is probably the most efficient alternative energy source because the sun will always be available to provide light.

You can read about the benefits of solar energy here:

http://www.greenstudentu.com/Solar_Energ...