An Evolutionary Model for Space Solar Power

Abstract

Abstract. The primary difficulties with the dream of Space Solar Power (SSP) for earth, are the extreme launch costs of solar power satellites to Geosynchronous Earth Orbit (GEO), and the absence of an evolutionary path to SSP. This makes the cost-tofirst-power unacceptably high. We present a 3-stage approach to SSP, and lay out the problems and opportunities. The key idea is to use space assets initially for global transmission and distribution, rather than generation, establish the infrastructure, and then add space-based power generation to a revenue-generating power grid. In the first stage, a Space Power Grid is established with satellites 1,200 km above Earth, distributing earth-generated beamed microwaves to other satellites and ground receivers. This boosts the earth-based alternative power industry (wind and solar-thermal) by providing transmission between any points on earth, and accommodating fluctuations in demand and supply. It also satisfies strategic needs for emergency power delivery. In Stage 2, direct power conversion technology will augment the existing space power grid with space-generated solar power. In Stage 3, large ultralight GEO reflectors will beam light to the direct-conversion collectors, and multiply the power through the grid. The need to put expensive, heavy solar arrays in high orbit is avoided, along with the objections to atmospheric transmission of visible light. The system would gain significantly from the development of low-mass, high-efficiency conversion equipment for direct conversion of broadband solar energy to beamed microwaves.

The Space Power Grid: Synergy between space, energy and security policies

“…The Space Power Grid (SPG) approach [6,7,8] seeks to break through this problem with an evolutionary, scalable approach to SSP within 25 to 30 years from project start, with a viable business plan and minimal costs to taxpayers. This paper deals with the interplay of technology, economics, global relations and national public policy involved in making this concept come to fruition.…”