A Concept GEO-SPS & Airship Multi-Megawatt Power Relay System

R. Dickinson (2005), JBIS, 58, 298-301

Refcode: 2005.58.298

Abstract:
An SPS power relay system for delivering multi-megawatts of grid electric power from GEO via a stratospheric airship platform is presented. A solar powered laser is proposed to beam power to InGaN band-gap matched PV located in a station- kept platform, where the received DC power is converted to 2.45 GHz microwave beams for relay to the surface using a phased array. To complete the power transmission link, spatially diverse, 260-m diameter rectennas provide the interfaces to the electric utility power grid. Unique requirements include that it is to be an all-weather electric delivery system, to be purposely designed to preclude its use as a power beam weapon at the Earth’s surface, and to be delivered to orbit in a single launch vehicle. Estimates are presented for the airship design assumptions, expected performance parameters and the various power conversion and power transfer efficiencies and the cost of the parts of the system, along with the suggested alternate revenue sources for making the high altitude platform more cost effective. Unfortunately, the cost to orbit dominates. The sunlight-to-grid power collection, conversion and transfer efficiency of order 8.2% is double that of ground based PV systems given their day-night, atmosphere and weather handicaps.