European Space Agency mulling feasibility of space-based solar power

The ESA has shared project details for an initiative designed to harvest the sun’s energy in space before wirelessly transmitting it to receiving stations on Earth.

The Solaris initiative plans to beam down energy from orbit to back up weather-dependent renewables. ESA said it is investigating the feasibility of developing the project alongside policymakers, energy suppliers and space companies. It aims to make an informed decision by the end of 2025 on how to proceed with a development program.

ESA said the uninterrupted nature and scalable potential of space-based solar power could offer a solution to current and future energy challenges.

“The threat of the climate of crisis demands that we work together to explore alternative technologies to achieve carbon neutrality – and, if implemented, space-based solar power could play an integral role in addressing this energy challenge, beginning as early as the 2030s,” said Sanjay Vijendran ESA’s Solaris lead.

Vijendran, who is set to present Solaris at the International Conference on Energy from Space in London this week, said that the physics behind the space-based solar power system is already implemented in telecommunications, where satellites beam small amounts of energy in the form of radio-frequency waves from orbit to a receiving ground station.

“The difference with space-based solar power is that the amount of energy transmitted and successfully collected would need to be far larger to make the venture viable – this presents many technological hurdles to be overcome,” said Vijendran.

The Solaris project is currently investigating a secondary concept that would use large mirrors deployed in space to reflect sunlight down through the atmosphere to existing terrestrial solar farms. The ESA said that this could serve as a forerunner to radio-frequency solar power satellites.

ESA said the reflector design “poses fewer technical challenges” than the radio-frequency concept, meaning it could be implemented earlier to test technologies that are eventually used in radio-frequency solar power constellations.

The agency’s future work will address the potential challenges of space-based solar power, which will likely include the anticipated scale of both the solar farms in space and the receiving stations on the ground.

“The challenges associated with space-based solar power are looking more surmountable than ever, thanks to low-cost reuseable launch systems, and advances in robotics, in-orbit servicing technologies and wireless power transmission,” said Vijendran.

In late 2022, UK-based engineering solution firm IECL began developing a project to generate solar power in space for terrestrial energy needs. In early 2023, the California Institute of Technology launched a small craft into orbit to test the efficacy of space-based solar power. pv magazine usa reported on its progress in June 2023.