Scientists discuss installing solar farms in space
An ambitious project to harness the power of the sun from space to supply power on Earth is being proposed by scientists.
The European Space Agency (ESA) – which includes the UK – is discussing plans to create a solar farm in orbit at a two-day conference in Paris.
How would it work?
The project aims to collect sunlight over a wide area in space, convert it to microwave energy (similar to high-frequency radio waves found in a microwave oven), and then transmit it down to Earth.
The beams would be captured by a large number of antennas on Earth, and the energy would be converted into electricity.
According to research commissioned by the government from consultants Frazer-Nash, an “operational system could be developed by 2040” and it could deliver “a substantial percentage of the UK’s energy needs by the early 2040s”.
The principle of SBSP has already been demonstrated on a small scale. In September, Airbus beamed microwaves between two points over a distance of 36 metres, producing green hydrogen and bringing a model city to life.
The UK also has its own separate proposals which the UK Space Agency and the UK government are aiming to make the idea a reality. Funding worth £6m has been made available to develop SBSP technologies aimed at contributing to the UK’s net zero ambition.
Could it work?
The advantages of Space Based Solar Power (SBSP) are huge because microwaves can penetrate clouds in Earth’s atmosphere and sunlight in space is also available constantly – not just during the day – and the light is more intense.
However, there are challenges. Jean-Dominique Coste from the team at Airbus said: “If satellites were to collect the sunlight, they would need to measure about 2 kilometres across to achieve the same power level as a nuclear power plant.”
As well as this, the ESA admits large amounts of energy could be lost during the conversion and “beaming” process, although scientists still think it would be economically viable even if only 10% reached Earth.
Meanwhile, experts will need to alleviate health concerns from beaming microwaves into the atmosphere – an effect that’s not been fully explored – by carrying out tests to ensure there are no risks to plants and animals.