The September 2009 issue of National Geographic has a comprehensive series of articles on the state of solar power. Here’s the online version of one of the articles. What is the potential of solar power?
“The total power needs of the humans on Earth is approximately 16 terawatts,” he said. (A terawatt is a trillion watts.) “In the year 2020 it is expected to grow to 20 terawatts. The sunshine on the solid part of the Earth is 120,000 terawatts. From this perspective, energy from the sun is virtually unlimited.”
In the late 1960's I personally noticed that almost every roof in Israel had a solar collector. Most of them were just for hot water, but the overall energy savings for the only country in the Middle East without oil was significant.
Maybe its time that the U.S.A. attempts to catch up to a tiny nation in the middle east for solar collection.