Solar power is a booming industry right now as we all strive to run our lives with minimum carbon footprint. Solar is a relatively easy way to get clean electricity but of course we are limited to the hours then Sun is above the horizon. Solar panels in space have been muted before but the costs and technology to transmit power to Earth is prohibitive. An alternative approach has been explored by a team of engineers who have been looking at the possibility of deploying giant reflectors into space.
They are a familiar site on houses these days, panels of crystalline-silicon that convert light into electricity. Solar panels have to be positioned carefully to maximise incoming sunlight and thus maximise electricity generation. If a way could be found to increase the amount of time a solar panel was in sunlight then of course they would be more useful to us. In 1993, a 20metre Russian space mirror known as Znamya-2 was unfurled to demonstrate that sunlight could be reflected down to Earth.
The concept to use reflectors in space to prolong the time that solar panels are illuminated is a far simpler and cheaper solution to some sort of solar power station in space. Arguably one of the key times in the day when power is needed is at night so being able to extend the hours of sunlight seems like a great concept. It’s not a new idea though as Hermann Oberth suggested it back in 1929 when he visualised giant reflectors in space, reflecting light down to areas that need it.
A paper recently published explores the reality of the concept and shows how the vision of Oberth may now be achievable. It should be noted that the idea is designed to target sunlight onto solar farms rather than individual homes. The technology is now available and materials suitable to be able to create, launch and deploy large solar reflectors into space. Once deployed, an orbiting reflector could be angled to direct sunlight onto a solar farm as it passes over, extending the ‘day’ and increasing electricity generation.
The reflectors which are proposed to be hexagonal with sides 250 metres long would likely be deployed into orbits at an altitude of about 900km. This would illuminate an area approximately 10km across and extend generation time by around 20 minutes either side of dusk and dawn.
Concerns that these would destroy the night are likely to be unfounded due to the planned approach to target solar farms away from inhabited areas. The reflectors would not be visible ot the naked eye unless you happened to be standing near a solar farm at the time it was beign illuminated and astronomical observations protected by angling the reflectors when not in use.
It is likely to be some years before such a project became reality but it is nice to see engineers and scientists looking at ways to enhance the generatin of clean energy in a way that promotes protection of our planets natural resources but also limits negative impacts on human activity.