The biggest problem with power satellites is the cost to lift parts to GEO. It's possible to do this for a dollar a kg considering only the energy. Unfortunately, rockets are inefficient and expensive. The expense is multiplied by the low payload fraction. High payload fractions are only possible with exhaust velocity substantially higher than any chemical fuels will provide. The best currently known combination is hydrogen and air while there is air to burn with hydrogen and above that, laser heated hydrogen. The start up problem is to push ~3 GW of laser into GEO without the help of a laser. This masses about 15,000 tons. It would require 1000 Skylon flights (or 300 Falcon Heavy flights). On power beamed from earth and electric thrusters, the LPS would be flown out to GEO. There it could lift as much as 500,000 tons per year at a cost of $100/kg or less. This is enough to build 100 GW per year of new power satellites. The economic model indicates 500% ROI in ten years. The Skylon is expected to be available by 2021, the laser could be in place two years later, first power satellites by 2023 or 2024. There is a writeup here: http://theenergycollective.com/keith-henson/362181/dollar-gallon-gasoline But I am not the person to make the project into a proposal easy to understand by the contest judges and community. If someone would like to do that, let me know. Keith Henson message: keithhenson email: hkeithhenson@gmail.com website: http://en.wikipedia.org/wiki/L5_Society