SRC-027

SPS-ALPHA: The First Practical Solar Power Satellite via Arbitrarily Large Phased Array

Published claims resting on this source

• CLM-0188 (low confidence) A 2012 NASA-funded concept study shows its own cost estimate falling from about $3.26 per kWh for a small near-term system down to about 9 cents per kWh for a much bigger system built with assumed future technology improvements - and the author states plainly that this headline low figure is only an early-stage estimate ("TRL 3"), not a validated cost.
• CLM-1218 SPS-ALPHA's design catches sunlight with a few thousand units of large, thin plastic-film mirrors. The mirrors are grouped into several hundred assemblies, and each assembly points on its own, like the mirrors around a solar tower plant, but the frame they sit on stays still, so the design needs no big moving joint.
• CLM-1219 (low confidence) SPS-ALPHA's mirrors concentrate sunlight about three times on the array. The report estimates that five times would save almost 15,000 tons, if the array could stand the extra heat.
• CLM-1220 The receiving site sends a guide signal up to the satellite, and the satellite's many small transmitters use it to line up their beams on that site. The design uses 2.45 GHz microwaves.
• CLM-1321 The 2012 design study for SPS-ALPHA put the weight of its 2 gigawatt satellite at about 35,000 tonnes, about half of it in the transmitter.

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