UK-based startup Space Solar is turning heads with a potentially transformative idea: beaming solar power from space. The company aims to deliver uninterrupted, clean energy to Earth using wireless transmission from orbit.
The centerpiece of this endeavor is the Cassidi project, a comprehensive 18-month, $2.26 million assessment funded by the UK Space Agency and the Department of Energy Security and Net Zero. The project evaluated every component of Space Solar’s power-beaming architecture, from the in-space assembly of solar arrays to the ground-based receivers that will eventually catch and convert the energy for everyday use. The result is a massive 1,700-page technical roadmap for Cassiopeia, the company’s flagship satellite. This orbital platform, whose name stands for Constant Aperture Solid State Integrated Orbital Phased Array, reflects a milestone in space-based solar engineering.
The Cassiopeia satellite will host thousands of lightweight photovoltaic modules in geostationary orbit, where they will continuously capture sunlight and convert it into high-frequency radio waves. These energy beams will then be directed to Earth-based receivers, delivering reliable power through all weather conditions and during the night—two persistent obstacles for ground-based renewables.
Key to this vision is Space Solar’s use of pre-fabricated solar reflectors that steer the beam electronically. The technology eliminates moving parts and drastically improves reliability and efficiency, while also enabling full 360-degree targeting from orbit. The beam itself is designed to be low intensity and safe, ensuring minimal environmental impact and compatibility with existing infrastructure. These innovations are foundational to Cassiopeia’s affordability and scalability.
The Harrier demonstrator, a crucial success of the Cassidi project, helped prove that power-beaming technology is viable in real-world conditions. This small-scale test model validated critical systems and paved the way for full-scale implementation. With 22 partner organizations contributing to the research, the project confirmed not just the technological feasibility but also the economic promise of space-based solar power.
Looking ahead, Space Solar has an ambitious timeline. It aims to roll out a commercial system capable of generating megawatt-scale power within five years. By 2036, it plans to scale up to a full product range spanning from 30 MW to gigawatt-level systems.
If achieved, this would place space-based solar on par with some of the largest terrestrial power stations, offering a continuously available, globally distributable clean energy source.
The question now isn’t whether space-based solar can work; it’s how soon it can be deployed, and how dramatically it will reshape our energy future.
