What are the main constraints on space-based solar power?

The main constraints on space-based solar power fall into several categories. Launch economics is the dominant constraint: delivering the mass of a functional solar power satellite to geostationary orbit is extremely expensive with current technology. Orbital assembly is the second major constraint: a full SBSP satellite would be too large to launch in one piece and requires assembly in orbit using robotic systems that do not yet exist at the required scale. Wireless power transmission at the required aperture and efficiency has been demonstrated only at small scale. Rectenna infrastructure requires large land areas that must be secured, regulated, and connected to the grid. Safety and regulatory frameworks for high-power microwave beaming do not yet exist at a level that would support commercial licensing. Space debris risk increases for large orbital structures. Finally, financing a multi-decade, multi-billion-dollar infrastructure project with a technology that has not been demonstrated at commercial scale presents significant capital formation challenges. These constraints interact: progress on launch costs reduces but does not eliminate the other barriers.