35 Appendix A: Representative Design Details Two design references were assessed in this study: Representative Design One (RD1) or "Innovative Heliostat Swarm" and Representative Design Two (RD2) or "Mature Planar Array." Both designs are assembled and operate in GEO. The Aerospace Corporation assessed each of the design references based on source materials. NASA updated elements of these designs with more recent technical data, as seen in the tables below, and scaled the systems to each deliver about 2 GW of power to the grid. Both systems operate in geostationary orbit. Details on the concept of operations and attendant calculations are provided in Appendix B. Innovative Heliostat Swarm is broadly derived from the Alpha Mark III concept (Mankins, SPS-Alpha Mark-III and an achievable roadmap to space solar power, 2021). This design uses reflectors and a concentrator to focus sunlight throughout each day. Mature Planar Array is broadly derived from the Japan Aerospace Exploration Agency (JAXA) Tether and Caltech SSPP design (Sasaki, A new concept of solar power satellite: Tethered-SPS, 2006), (Sasaki, Demonstration Experiment for Tethered-Solar Power Satellite, 2009), (Pellegrino, 2022). This design uses flat panels, with solar cells facing away from the Earth and radiofrequency (RF) emitters facing toward the Earth. This design has a lower capacity factor due to limited capability to reposition itself or redirect sunlight toward its solar cells. This study did not fully account for the changes in the Sun’s position over the year, or how multiple RD2 systems in orbit may increase the capacity factor of the entire architecture. Multiple systems would increase the capacity factor; however, landmass on the Earth does not allow for even distribution across the day-night cycle, because much of the equator is underwater. This study is concerned with comparing representative examples of SBSP. Others may take the model developed for this study to further develop their own, more detailed analyses. The Aerospace Corporation provided data and analysis in the form of interim reports, a methodology paper, and spreadsheet.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==