The European Space Agency (ESA) will consider the viability of a gigantic solar farm in space at a meeting this week in Paris. If approved, a three-year study will begin on whether such a farm would be possible, cost-effective, and be able to wirelessly “beam” the energy back to Earth.
While the idea is certainly not new, it is often proposed as a concept but has never actually made it off the ground – should the study come back positive, it could be the first time officials actually try the bold plan.
The SOLARIS initiative would lay the groundwork for a possible decision to begin development of the farm in 2025, according to ESA. Such a project would aim to address the inherent limitations of solar energy on Earth, such as how energy cannot be produced during nighttime or under heavy clouds, by simply taking the solar cells above the atmosphere. It would massively increase the efficiency of the cells, with sunlight being around ten times more intense up in space (thanks atmosphere), and could be the answer needed to reach the European Net Zero pledge by 2050.
Of course, we have been using solar panels in space for decades, so this is certainly not an innovative idea; the tricky part arises in getting that energy back down to Earth.
The reference design and leading idea on how ESA would do it is via 2.45 gigahertz microwaves. The energy would be taken from the photovoltaic cells and transmitted over microwaves down to receiver stations on Earth, called ‘rectennas’, which would then convert it back to electricity and feed it to the grid.
The best part is, once the power station is up and running, the target doesn’t need to be Earth – when humans eventually make it to Moon colonization, power could be sent there too.
Going through with SOLARIS would cement Europe as a “key player – and potentially leader – in the international race towards scalable clean energy solutions”, writes ESA.
Some challenges still need addressing: right now, both the satellite and the receiver stations would need to be very, very large; and the cost of many rocket launches to build something that weighs thousands of tons in orbit would be astronomical. However, it could still be significantly cheaper than current solutions for the same level of energy output.