Solar power stations in space that beam ’emission-free electricity’ down to Earth could soon be a reality thanks to a UK government funded project.
Above the Earth there are no clouds and no day or night that could obstruct the sun’s ray – making a space solar station a constant zero carbon power source.
The UK government commissioned new research into the concept of space-based solar power (SBSP) stations as a way to meet the Earth’s growing energy needs.
The idea is that the stations would capture the Sun’s energy that never makes it to Earth and use laser beams to safely send the energy back to Earth.
It’s an idea first conjured by science-fiction writer Isaac Asimov in 1941 in his science fiction short story Reason where it was revealed a station a mile across was used as an ‘energy converter’ to gather sunlight and beam it across the solar system.
The team behind the study will examine three existing SBSP concepts from the US, UK and China with support from the inventors of the UK and US systems.
Above the Earth there are no clouds and no day or night that could obstruct the sun’s ray – making a space solar station a constant zero carbon power source
Funded by the UK Space Agency and the Department for Business, Energy and Industrial Strategy, the UK will explore whether this technology could offer a resilient and sustainable energy source in the future.
Today energy generation tends to be regional, but electricity generated by a space solar station could be beamed almost anywhere across the globe.
The study, led by the engineering and technology consultancy Frazer-Nash, will consider the economics of such a station – whether it could deliver more affordable energy for consumers, and the engineering feats required.
One of the biggest issues to overcome is that of getting an array of solar panels into orbit, large enough to make the project viable, at a competitive cost.
It’s an idea first conjured by science-fiction writer Isaac Asimov in 1941 in his science fiction short story Reason where it was revealed a station a mile across was used as an ‘energy converter’ to gather sunlight and beam it across the solar system
A typical system comprises a massive, kilometre scale Solar Power Satellite (SPS) in Geostationary Earth Orbit.
It has very lightweight solar panels and a system of mirrors to concentrate sunlight onto the panels, generating around 3.4 GW of electricity on the satellite.
This is converted into high frequency radio waves, with an efficiency of 85 per cent, according to a spokesperson for the research project.
A secure pilot beam is transmitted from the ground to the satellite to allow the power beam to lock onto the correct point.
The ground rectifying antenna or ‘rectenna’ converts the electromagnetic energy into direct current electricity and then through an inverter which delivers a net 2 GW of AC power into the electricity distribution grid.
Science Minister Amanda Solloway said it could provide energy to everyone, even in places like northern Europe and Canada that don’t receive year-round sunlight.
‘Space solar stations may sound like a piece of science fiction, but they could generate an entirely new source of energy for the UK, while helping us slash our emissions and smash our climate change targets.’
Historically, the cost of rocket launches and the weight that would be required for a project of this scale, made the idea of space-based solar unfeasible.
The study, led by the engineering and technology consultancy Frazer-Nash, will consider the economics of such a station – whether it could deliver more affordable energy for consumers, and the engineering feats required
The SPS weighs several thousand tonnes, and the designs aim to maximise the specific power in kW per kg, as this strongly determines the cost of manufacturing and deploying the system.
Estimates for the systems being considered in this study have independently calculated the Cost of Electricity at less than £3.79 per MWh.
This would be a competitive energy cost if it can be realised, UK Space Agency said.
The cost has come down in recent years due in part to the new age of privately-led space ventures bringing down the cost of launch in the past decade.
Funded by the UK Space Agency and the Department for Business, Energy and Industrial Strategy, the UK will explore whether this technology could offer a resilient and sustainable energy source in the future
A UK Space Agency spokesperson said there are a number of benefits including producing a clean, zero carbon source of energy.
SPACE-BASED SOLAR POWER (SBSP)
The idea of Space-Based Solar Power stations have been around since 1941.
Science fiction writer Isaac Asimov first wrote about them in the short story Reason.
This is one artists impression, produced for NASA, of what a space solar array might look like. The idea would involve capturing the rays and beaming them down to the Earth
In the story he wrote about a space station that transmits energy collected from the Sun to various planets using microwave beams.
There were a number of concept designs from the 1970s but non were deemed economically viable.
The basic concept involves a space station with a solar array to convert solar energy into electrical energy.
Then it would use a microwave transmitter or laser emitter to transmit the energy to a collector on the Earth.
The UK has joined Japan, China, Russia and the US in pursuing the idea of space based power generation.
As of 2008, Japan made the idea of space solar power a national goal.
Advantages of the technology include the fact it is always solar noon in space with a full Sun.
Collecting surfaces could also receive more intense sunlight than on Earth.
However they would be large satellites, costing a lot of money to launch – although launches have become cheaper thanks to commercial firms.
This would lead to affordable energy for homes and industry and a secure and resilient indefinite fuel supply.
Assuming it turns out to be commercially viable, the system could be developed and made operational by 2050, in time to make a substantial contribution to Net Zero carbon emissions.
Martin Soltau, Space Business Manager at Frazer-Nash said the study will require expertise in the space, energy and aerospace sectors, and a strong understanding of existing SBSP technologies, their relative merits and maturity.
‘We have also partnered with Oxford Economics, who have significant experience in the space sector, and who will provide additional strength and depth to the economic assessment element of this study,’ said Soltau.
‘We will be forming an expert panel, comprised of leading SBSP experts and space and energy organisations, to gain a range of industry views and to enhance the authority of the technology development roadmap.’
A UK SBSP system might comprise 5 satellites, producing 10GW, as part of a mix of clean energy technologies.
As the effects of climate change become more devastating, prominent research institutions and Government agencies are focusing new money and attention on radical ideas to reduce global warming.
In 2019 Britain passed an important milestone, with more electricity generated from sources like wind and solar and nuclear power that produce no carbon-dioxide emissions than from carbon-emitting fuels like natural gas and coal.
According to the World Resources Institute – a Washington-based non-profit that tracks climate change – Britain has reduced carbon dioxide generated in the country by about 40 per cent, which is more than any other major industrialised country.
Dr Graham Turnock, Chief Executive of the UK Space Agency, said the sun never set sin space so space solar power systems could supply renewable energy to anywhere on the planet day or night, rain or shine.
‘It is an idea that has existed for decades, but has always felt decades away,’ he said.
‘The UK is growing its status as a global player in space and we have bold plans to launch small satellites in the coming years. Space solar could be another string to our bow, and this study will help establish whether it is right for the UK.’
A spokesperson said there are broader societal, political, and regulatory considerations which are not part of this study and which would need to be looked at in future.
SOLAR POWER EXPLAINED: ENERGY IS CONVERTED FROM SUNLIGHT INTO ELECTRICITY
Solar panels convert energy from the sun into electrical power (stock image)
Solar power is the conversion of energy from sunlight into electricity.
Two methods for generating solar power exist.
Photovoltaics — the kind of solar panel you might see built into a calculator — are capable of directly converting light into electrical power.
In concentrated solar power systems, however, mirrors or lenses are first used to collect the sunlight that falls on a large area and focus it — creating heat that can be used to drive a steam turbine and generate electricity.
The productivity of solar panels is dependant on the sunlight they receive in a given location — a factor which is dependant on both latitude and climate.
Optimum locations for solar farms include the arid tropics and subtropics, with deserts lying at such low latitudes often being cloudless and getting around 10 hours of sunlight each day.
According to NASA, the eastern part of the Sahara — the Libyan Desert — is the sunniest place on the Earth.
Solar power accounted for 1.7 per cent of the world’s electricity production in 2017, and has been growing at a rate of 35 per cent each year.