Power from space and the hydrogen economy

Recent discoveries of methane hydrates under the Arctic permafrost and on continental shelves have revealed an immense energy resource. This has two major implications for the Solar Power Satellite (SPS). First, the SPS will not be built unless it can produce electricity at a price competitive with that generated using methane from hydrates (perhaps with sequestration of carbon dioxide). Second, steam reformation of methane is much cheaper than water electrolysis as a source of hydrogen, so there is little role for the SPS (or any other electric power technology) in the proposed hydrogen economy. On the other hand, an economy based on methane-electric hybrid vehicles offers advantages quite comparable to the hydrogen economy, without its technical problems and immense capital requirements. The methane economy also offers a transitional path to increasing direct use of electricity in transportation, a development that could create a major market for the SPS.