Nanotechnology and Renewable Energy
By realneel on Aug 09, 2006
Efficiency of Solar cells vary from 2% to 35%. As the efficiency increases, cost increases non linearly. It is interesting to note that the amount of energy consumed by the United States in one year is roughly equal to the amount of solar energy received by the earth in one hour! To generate 3TW a year (the current US power usage) using a 3% efficient solar technology would require solar cells to cover an area that is roughly equal to the size of Texas!. The cost per kilowatt will be much higher too.
Disclaimer: I did not take notes during the talk, so my numbers may be slightly off. But I guess you get the big picture