Since 2013, the California Institute of Technology (Caltech) in Pasadena is researching a way of collecting solar energy in space and sending it to earth in the form of microwaves. Unlike on Earth, sunlight would be available around the clock to convert it into electricity in space – regardless of the time and weather conditions. As part of the Space-based Solar Power Project (SSPP), the Caltech researchers have already developed corresponding prototypes.
Solar energy from space: Prototype starts in 2023
A first satellite is to be tested in space in 2023. The prototype with solar power generators and hardware for wireless energy transmission should have a three square meter retractable sun sail, as announced by Caltech. The research team is certain that this type of energy generation – if it is carried out on a large scale – could satisfy the increasing demand for electricity on earth.
By the way, Caltech has just given the name of the initially anonymous donor who invested over 100 million US dollars in the project in 2013. This is real estate billionaire David Bren. He has been researching possible applications for solar energy generation in space for many years. He is interested in the idea that the natural power of the sun should be used for the benefit of all.
Even Air Force working on space solar energy
Incidentally, Caltech is not the only institution working on such a project. The US Air Force wants to carry out a corresponding experiment in space in 2024. In addition, a space solar energy project is already running, as reported by Space.com. In May 2020, the US Air Force launched the Pram-FX (Photovoltaic Radio-Frequency Antenna Module Flight Experiment) solar module on board its X-37B spaceplane. This does not yet send energy to earth, but researchers have already been able to take some information with them from the experiments for their own experiments.

