Solar power satellites: technical challenges and economic feasibility

Abstract
World energy consumption is constantly rising; therefore, it is essential to investigate different possibilities to produce power in the medium and long term. The sun is a clean source of power that is virtually inexhaustible. Photovoltaic (PV) power stations are used to harness this energy, but they are not completely reliable since they depend on weather patterns. To overcome this problem, large satellites with extensive solar panel surfaces can be placed in orbit. These satellites, known as Solar Power Satellites (SPS), would be positioned in geostationary orbit (GEO) thus constantly providing energy while avoiding meteorological conditions and erosive factors. These benefits make solar power station an appealing option for the energy of the future. Therefore, in this paper, the possibility and challenges of using solar-powered satellites are explored. The mechanisms regarding microwave transmission, photovoltaic collection, radiation impact, and propulsion are discussed. The advantages and disadvantages of solar-powered satellites are discussed regarding cost and practicality, and the current race between different countries to achieve this technology was examined. It was found that power could be collected with an efficiency of over 30% using gallium-arsenide photovoltaic cells. To minimize radiation effects, the use of a 100-micron transparent Pilkington Borosilicate Glass (commercially known as CMG cover glass) could be employed. For spacecraft propulsion, Hall thrusters provide the optimal combination between efficiency and thrust. Finally, the cost analysis indicates that to make the SPS viable, launch costs to GEO must be decreased by a factor of 10, solar panel efficiency must be increased to 40%, panel density must be minimized, and international cooperation must be achieved.