University of Wisconsin-Madison

There are 3 interesting observations one can make from the LSPS reference design. First, the conversion efficiency of a lunar solar watt into electricity in the grid on the Earth is surprisingly low. Data taken from Criswell (1996), shows that when the nature of the fixed E-W facing triangular Si solar cells are taken into account, only ~ 6% of the solar energy/cm2 is actually incident on the Si collectors. Since the Si converts the solar energy to electricity @ ~ 10%, less than 1% of the incident solar energy ends up as electricity on the Moon. When the conversion to microwaves, transmission to Earth based rectenna, and conversion back to electricity is accounted for, less than 0.3% of the solar energy incident on the Moon would actually end up as electricity in the Earth grid. Because of this inefficiency, it would take ~ 15% of the Moon's surface to produce 20,000 GWe on Earth, roughly all the area in the Mare of the Moon.