Assess space-based solar power for European-scale power system decarbonization

Meeting net-zero targets is challenging, as terrestrial renewables face intermittency and regional constraints. Here, we assess space-based solar power, a near-constant source, using a high-resolution, Europe-wide capacity-expansion and dispatch model. We assess two advanced designs: (1) a near-baseload, low-TRL (technology readiness level) heliostat design and (2) a partially intermittent, higher-TRL planar design, using NASA’s 2050 forecast. We find that the heliostat design can cut total system costs by 7%–15%, offset up to 80% of wind and solar, and reduce battery usage by over 70%, although hydrogen remains vital for seasonal balancing. The planar design, by contrast, is uneconomical at its forecast costs. Sensitivity analyses reveal relative cost thresholds for both designs, at which space-based solar shifts from cost-prohibitive to complementary and ultimately to a dominant baseload source for net-zero transitions. These results provide robust techno-economic benchmarks, highlighting new net-zero pathways and guiding policymakers and industry toward large-scale, low-intermittency renewables.