The European Space Agency (ESA) has launched a pair of complementary studies to help develop space-based solar power stations that would “beam” energy down to Earth. Collecting energy from the Sun in space, where it is plentiful and available continuously, would overcome two traditional limitations of solar power — that of susceptibility to weather and the time of day.
Part of the ESA’s wider “SOLARIS” initiative to investigate space-based solar power, which was formally approved late last year, the studies will be led by the consulting firm Arthur D Little and Thales Alenia Space Italy and are expected to be completed before the year is out. SOLARIS as a broader programme will help Europe to decide by 2025 whether or not to launch a full programme to develop commercial-scale solar power plants in orbit.
SOLARIS lead and physicist Dr Sanjay Vijendran said: “These contracts are for the first European concept studies of space-based solar power in more than 20 years, so today marks an important step.
“We are really starting from a blank sheet of paper to get an up-to-date design for what working solar power satellites could look like, sourcing promising ideas from everywhere we can and leveraging the latest advancements in space and terrestrial technologies.”
In particular, the studies will be tackling the issue of exactly how to beam down solar power from orbit — starting from a “blank sheet” approach to the challenge.
Dr Vijendran added: “The studies will look at as wide a range of options as possible, including investigating all the different ways to move the energy — safely and efficiently — down to Earth.”
Such approaches, he explained, might include radio frequency transmission, lasers, or even simply reflecting sunlight down for collection at solar farms on the surface of the Earth.
Dr Vijendran continued: “We are happy that we have major energy players like the French electricity utility ENGIE and the Italian utility ENEL included as members of the study consortiums.”
This, he added, reflects “the potential value the energy sector is already seeing in this capability for the future.
“It’s important that we engage the energy sector right from the start of this development and listen to their needs.”
In this way, he said, we will “know from the beginning that we are building something that end users will want and use.”
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In what is an usual situation for two such early phase projects, both are being implemented by the ESA as if they were flight projects — that is, giving them a rapid pace and strict milestones.
The hope is to use the results of the studies to inform follow-ups into the potential to develop a small scale demonstration mission.
Leopold Summerer is the head of the ESA’s Advanced Concepts and Studies Office. He said: “These activities demonstrate the importance of ESA’s Preparation element in supporting ambitious ideas to become a reality.”
“Preparation-funded activities help ESA assess the interest from European industry in novel topics and lay the groundwork for future research and technology development to make them happen.”
Dr Vijendran added: “There are a lot of fundamental reasons why space-based solar power is looking a lot more feasible and desirable than ever before.
“These include the reduced cost of launch to orbit with the advent of reusable launchers, the reduced cost of satellite hardware through mass production — seen with new constellations such as Starlink and OneWeb — and trends towards very modular solar power satellite designs.
“In addition, space robotics and in-space assembly and servicing technologies have really come a long way in the last two decades, which will be essential for the construction and maintenance of solar power stations.
“Finally, the sheer challenge of transitioning to Net Zero within the next 25 years with existing technologies — and the consequences of not doing so — demands exploration of alternative solutions that could help make sure we achieve our goal.”
Europe is far from alone in exploring the potential of harvesting energy from space. Early this year, researchers at the California Institute of Technology launched a “Space Solar Power Demonstrator” satellite into orbit to test key technologies, including the microwave transmission of solar energy up in space.
Meanwhile, Japan and China are looking to launch demonstrator missions in 2025 and 2028, respectively — with the latter have already constructed a ground-based wireless power transmission test facility to explore the underlying science.
The UK Government, meanwhile, is in discussions with Saudi Arabia to help supply the planned smart city of Neom — north of the Red Sea and East of the Gulf of Aqaba — with carbon-free electricity from space.
