Sustainability Spotlight, June 2021 - SOLSPACE: Solar Reflectors for Clean Energy
Imagine a thin reflective film held in tension by a lightweight gossamer structure, perpetually moving along the day-night terminator as it circles the Earth on a high polar orbit. From this vantage point the reflector will always be illuminated by the Sun, but looking down it will also see the terrestrial twilight band of dawn and dusk.
In principle the reflector, or a constellation of reflectors, could redirect sunlight to illuminate large-scale solar power farms just after sunset when their output fades, but evening energy demand and spot prices are high. In doing so the reflectors would improve the utility of intermittent solar energy and help deliver more clean energy into the global energy grid.
While solar reflectors have been considered in the past, the combination of the rapidly growing global demand for clean energy, falling launch costs through reusability and the prospect of in-orbit manufacturing makes this an adventurous but timely proposition.
Through the €2.5M European Research Council SOLSPACE project led by Professor Colin McInnes at the Space and Exploration Technology Group (James Watt School of Engineering), a team of researchers have begun to explore the opportunities and challenges of delivering such new global energy services.
The works spans themes devising new families of reflector orbits (Dr Onur Çelik), reflector pointing control strategies (Dr Andrea Viale), reflector design and manufacture (Dr Litesh Sulbhewar), and economic and energy systems analysis (Dr Temitayo Oderinwale). A key task for the project will be to devise strategies to minimise stray light reflection while ensuring that new energy services can be delivered globally to multiple large-scale solar power farms.
Images:
Representation of a train of mirrors reflecting sunlight to a photovoltaic farm on Earth: in-orbit view (top), ground view (bottom). The mirror size is not to scale.
Image credits: Dr Andrea Viale, used with permission. Top image includes Earth Texture Map, NASA.