This paper reports continuing work on an evolutionary revenue-generating approach to Space Solar Power. The 220 GHz atmospheric transmission window is chosen, leaving open the option of using millimeter wave or laser wavelengths. The progression from frequency to system business case is laid out, seeking the performance figures needed for a self-sustaining system and to open up Space Solar Power in 15 to 17 years from first launch. An overall transmission efficiency in excess of 30 percent is required, from DC to beamed power and back to DC or high-voltage AC, to meet a delivered free-market price target of 30 cents per KWH, or 20 percent if a price of 45 cents per KWH. Climate data show that rain obscuration is a non-issue for many of the renewable-power sites that comprise the market. The technology of direct solar conversion to DC and to beamed power would satisfy the needed efficiencies but requires advances in nano-scale fabrication with dielectrics.

This paper continues work on an evolutionary, revenue-generating approach to Space Solar Power. In previous work, a 3-stage, self-sustaining program was proposed, that enables growth to full Space Solar power in 20 to 30 years. The approach is to first use a constellation of spacecraft in sun-synchronous orbits as a microwave power grid connecting renewable energy plants situated around the world. This step generates revenue primarily from the large temporal and geographic variations in cost and supply of electric power. It enables location of new renewable power plants in remote locations, and minimizes reserve needs for baseload qualification. In a second phase, replacements for the first generation satellites would incorporate converters from solar power to microwave beams, followed by placement of large ultralight collectors in high orbits to beam sunlight directly to the converters. Recent developments have improved options in the near millimeter wave regime. In this paper, the Phase 1 architecture is altered to investigate the minimum power level at which the system will pay for itself in 30 years. Cost estimates are related to the published literature and shown to be conservative. Parameter choices are systematically related to the Net Present Value.

This paper studies the technological, economic and public policy issues and opportunities in developing a renewable energy economy based on devices of less than 5KW , suitable for retail marketing. The research question is whether such systems can be popularized in the retail marketplace to the extent that families and non-governmental organizations will adopt them on a scale that substantially augments global renewable power generation. The reduction in efficiency of a MRES is discussed with regards to other more prevalent energy technologies and the numerous benefits that warrant further developments are presented. Five concepts using wind, solar, and biomass energy are considered, and of these, the symbiotic solar algae system is explored in detail. Its design, cost and impact are considered. Policy initiatives suggested.