[Wonder Warthog]

"The issue is not just one of just manufacture, it is also the cost of placing in orbit and maintaining the orbital array, not to mention developing means to transmit the energy to earth in a useful form that does not create its own environmental/health problems."

The study I am referring to was not for space-based solar cells, but earth-based arrays. The study (which was in a peer-reviewed journal)did a complete energy cycle analysis assuming a complete solar array production facility running only on energy produced from solar cells, and calculated the "breeder cycle efficiency" which was positive. This was back in the mid-1980's, so the numbers would be significantly better today, given the more energy-efficient production processes not available back then.

Earth-based solar arrays are certainly practical--more expensive than nuclear, to be sure, but there are no technological barriers to building them. Compared to the amount of desert land in the United States, the fraction of such land necessary to provide the entire energy needs of the US (NOT just electrical power) is small.

[ancient_geezer]

Now what would such an array buy us, in regard to any Global climate change induced by human activity? As an answer to effecting changes in global climate, if we assume that it could remove all human induced CO₂ contributions to the atmosphere the net effect would be a change on the order of 0.2% of the related energy budget of the earth that can be even remotely attributed to the atmosphere's CO₂ content.

What impact, if any, does a big heatsink in the desert(e.g. solar energy array) have on climate patterns? What impact does the conversion of electical energy transfered to the atmospher in the form of atmospheric heat, have upon the climate, in lieu of fossil fuel burning which tend to lock up heat in the formation of CO2 & water vapor.

What would the net change to the earths heat balance, and its consequent effect on climate in going to a solar only solution?