Solar power farms to be enhanced with space reflectors

Researchers from the University of Glasgow have proposed an innovative approach to enhancing solar power generation that could significantly contribute to achieving net-zero emissions. Their study suggests that deploying kilometre-sized reflectors into space could increase the energy output of future solar farms by directing extra sunlight toward them at dawn and dusk.

This concept was detailed in a preprint paper in Acta Astronautica, where the team explained their use of advanced computer simulations to explore the optimal use of space-based solar reflectors for additional power generation. According to their findings, placing twenty ultra-thin reflectors in orbit approximately 1,000 kilometres above Earth could extend sunlight exposure to solar farms by an average of two hours daily. This extension could be particularly beneficial after sunset, a peak period for electricity demand, and efficiency could be further enhanced by either increasing the number of reflectors or their dimensions.

The reflectors would be positioned near the Earth's terminator line, the divide between day and night, arranged in a formation known as a Walker constellation. This setup, common in satellite communications for ensuring continuous coverage, would allow for the strategic placement and angling of reflectors to optimally capture and redirect sunlight to solar farms during early morning and late evening hours.

Through the development of a specialized algorithm, the team determined the most effective configuration for these reflectors to maximize the reflected sunlight. Their projections indicate that these twenty reflectors could contribute an additional 728 megawatt-hours (MWh) of electricity each day, equating to the output of a substantial new solar farm but without the need for ground-based construction costs.

Dr Onur Çelik, from the University of Glasgow’s James Watt School of Engineering commented: “Solar power has the potential to be one of the key accelerators in our race to reach net-zero, helping us to mitigate the global impacts of climate change by reducing our reliance on fossil fuels.

“The price of solar panels has dropped quickly in recent years, increasing the pace of their adoption and paving the way for the creation of large-scale solar power farms around the world.

“One of the major limitations of solar power, of course, is that it can only be generated during daylight hours. Putting orbiting solar reflectors in place around the Earth would help to maximise the effectiveness of solar farms in the years to come. Strategically placing new solar farms in locations which receive the most additional sunlight from the reflectors could make them even more effective.”

The paper is an output effort of SOLSPACE, a University of Glasgow-led research project funded in part by the European Research Council.

Professor Colin McInnes, SOLSPACE’s Principal Investigator, added: “The idea of orbiting solar reflectors isn’t new – in fact, it predates even the space age, as the idea of illuminating cities with light from space was first discussed in the late 1920s.

“However, space reflectors have only been demonstrated once back in the early 90s, when a 20-metre aluminium-foil reflector was released from the Russian Mir space station to reflect sunlight back to Earth.

“The SOLSPACE project is working to devise, develop and demonstrate ideas for orbital reflector technology that could work on a much more ambitious scale to deliver global clean energy services.

“Tackling the challenges of climate change requires big ideas. While this is undoubtedly a big idea, it builds on technologies that are already well-understood and computer models like ours show how they could be scaled up. In addition, the falling cost of launching payloads to space opens up entirely new possibilities for the future.”