6 Limitations of the study include: • This is a first-order assessment of notional systems: Cost and GHG emissions estimates are not exhaustive, and outputs are heavily influenced by assumptions about a technology with no historical data points built and operated in an unknown future. • The reference designs assessed are not representative of all proposed SBSP architectures: For example, systems in lower orbits have been proposed but are not assessed in this study. For a detailed methodology, broken out by each step of the analysis and including results, please see Appendix B. 2.1 Cost Estimations To estimate costs, we: 1) defined SBSP systems based on six key functions, 2) divided the SBSP system lifecycle into five concept of operations (ConOps) phases, generating cost estimates for each phase, and 3) used ConOps costs to determine the LCOE for comparison to other renewable energy technologies. 2.1.1 Functional Decomposition of SBSP Systems Generating electricity using SBSP systems involves six functions: collect solar energy in space, convert (in space) energy to microwave or optical energy, transmit that energy to Earth, receive the transmitted energy at one or more ground stations, convert (ground) that energy to electricity, and deliver electricity to the grid for consumption or to batteries for storage. This study assesses two representative SBSP designs: 1) the RD1 (Innovative Heliostat Swarm) concept, which uses a concentrator to improve its capacity factor, and 2) the RD2 (Mature Planar Array) concept, a less complex system that collects solar energy on one side and emits this energy as microwaves on the other. Figure 5 describes each reference design in terms of the six key functions; more detailed information on each concept is presented in Appendix A. 2.1.2 Concept of Operations The ConOps for each reference design is broken into five lifecycle phases: develop, assemble, operate, maintain, and dispose. Including disposal or decommissioning of a system is a best practice when assessing its full lifecycle. Figures 6a and 6b provide a visual summary of each ConOps phase. We estimate the cost of each SBSP reference designs by ConOps phase. Appendix A contains a detailed breakdown of each phase and all relevant parameters. Appendix B shows the mapping of ConOps phases to each functional step.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==