Technology

Space Based Solar Power

Wireless Solar Power Transfer From Space Possible, Proves Caltech’s Prototype Technology

Anu Bhambhani
  • Caltech says its MAPLE project has enabled transmission of solar energy from space to the earth
  • Transmitted energy was detected by a receiver at its Pasadena campus at expected time and frequency
  • Caltech claims this is the 1st time wireless energy transfer from space has actually been demonstrated

The California Institute of Technology (Caltech) says a space solar power prototype in orbit since January 2023 has now beamed back detectable power to earth wirelessly for the 1st time proving the potential of the technology that it claims can 'democratize access to energy'.

"No energy transmission infrastructure will be needed on the ground to receive this power. That means we can send energy to remote regions and areas devastated by war or natural disaster," said Caltech's Bren Professor of Electrical Engineering and Medical Engineering, and Co-Director of its Space Solar Power Project (SSPP) Ali Hajimiri.

SSPP developed the Microwave Array for Power-transfer Low-Orbit Experiment (MAPLE) as a prototype to carry out the actual experiment to collect sunlight, transform it into electricity, convert it into microwaves that can be transmitted over long distance to the earth via a small window.

Caltech says the transmitted energy was detected by a receiver on the roof of the Gordon and Betty Moore Laboratory of Engineering on its Pasadena campus at the expected time and frequency.

While the experiment is not final meaning large-scale SSPP units will be subjected to harsh space environment and wide temperature swings and solar radiation, the successful demonstration gives hope that it is possible to reach a time when space based solar power can be beamed to the earth providing an unlimited supply of clean energy irrespective of weather conditions or day and night constraints.

"To the best of our knowledge, no one has ever demonstrated wireless energy transfer in space even with expensive rigid structures. We are doing it with flexible lightweight structures and with our own integrated circuits. This is a first," stated Hajimiri.

The research project has been under development since 2011 and in 2021, Caltech officially announced it was going for a test launch of the prototype in early-2023 after Donald Bren whose brainchild the idea is, donated $100 million to the SSPP (see Caltech To Test Solar Power Generation In Space).

"Solar panels already are used in space to power the International Space Station, for example, but to launch and deploy large enough arrays to provide power to Earth, SSPP has to design and create solar power energy transfer systems that are ultra-lightweight, cheap, and flexible," added Professor of Applied Physics and Materials Science; Director of the Liquid Sunlight Alliance; and one of the principal investigators of the project, Howard Hughes.