Eventually we will consume all readily available fossil fuels. That moment seems to be rushing toward us. Some experimenters consider solar power to be an effective alternative. If so then we’d need to capture the Sun’s energy to the amount of 11099.3 mtoe or 4.66e20 J/a as we did in 2007.

Through measurements, we have a good grasp of the amount of solar radiation impacting upon the Earth’s surface. In the US it’s about 6 kWh/m2/day while in Europe it’s about 3.5 kWh/m2/day. Assuming it is 6, then this converts to about 7.884e13 J/ha/a. But, solar arrays operate at about 2.7% efficiency so we get even less.

With an annual demand of 4.66e20 Joules, a gathering of  7.884e13 J/ha/a and an efficiency of 2.7% then we’d need 2.2e8 hectares of solar collectors to generate the energy equivalent to the amount of primary energy used in 2007. This is about equal to the area of Greenland.

Is such an area available on the Earth’s surface? Can we build and maintain such an extent of solar collector’s? Do we have the time and the will? Should we sacrifice the land and ecosystem underneath the collectors?

BC Energy Blog