Space

UK government examining potential for orbital solar power plants by 2050

UK government examining potent...
Artist's concept of an orbital solar power station that could provide unlimited, constant, zero-carbon power
Artist's concept of an orbital solar power station that could provide unlimited, constant, zero-carbon power
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Artist's concept of an orbital solar power station that could provide unlimited, constant, zero-carbon power
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Artist's concept of an orbital solar power station that could provide unlimited, constant, zero-carbon power

The British government has commissioned a new study looking at the potential to build an orbital solar power station by 2050. Led by Frazer-Nash Consultancy, the new study looks into the feasibility of space-based solar power (SBSP) systems that use giant solar arrays to generate electricity and beam it to Earth in the form of microwaves.

As a major power source, solar panels have a number of disadvantages that have more to do with where they are than what they are. The most obvious drawback is that the Sun sets with aggravating regularity and without it, solar panels are just panels. Also, the Sun moves through the sky, so solar panels either have to settle for a very variable output or they have to include a tracking mechanism that allows them to follow the Sun to maintain the optimum angle.

Then there's the problem of weather. Not only can cloudy days effectively shut down a solar power plant, the fact that sunlight has to filter through the Earth's atmosphere means that it's attenuated, cutting down on the power output.

None of this has anything to do with the inherent technology of solar panels. It has more to do with the fact that the ones used to generate electricity on Earth are sitting on the Earth's surface. However, if a solar power plant could be set up in orbit, these disadvantages vanish. The Sun never sets, arrays can always be set at the ideal angle 24 hours a day, and there's no atmosphere to block or attenuate the light.

The question is, how to get that energy back to Earth? One answer is to send it in the form of a microwave beam, which is picked up by fields covered with dipole antennas and turned back into electricity before being fed into the grid.

The idea isn't new. It was first suggested by the science fiction writer Isaac Asimov in 1941 in his short story Reason, and a design for a power transmitter was patented by Peter Glaser in 1973. In 1976, Physicist Gerard K. O'Neil made building such solar power plants the main industry for his proposed orbital space colonies.

The trouble is that building such gigantic solar plants in geosynchronous orbit would be enormously expensive, so the idea keeps being relegated to some far off future date.

Now, encouraged by the prospect of lower launch costs through new commercial space companies, the British government is reviving the idea of orbiting solar power plants as a zero-emission alternative energy source and has commissioned a new study by Frazer-Nash Consultancy to see if the concept is both feasible and economically viable.

According to the UK Space Agency, the new research will look at both the engineering and economics of such plants with special attention on how to assemble such satellites in orbit on a huge scale.

"Decarbonizing our economy is vital," says Martin Soltau, Space Business Manager at Frazer-Nash. "We need to explore new technologies to provide clean, affordable, secure and dependable energy for the nation. SBSP has the potential to contribute substantially to UK energy generation, and offers many benefits if it can be made practical and affordable.

"Frazer-Nash is studying the leading international solar power satellite designs, and we will be drawing up the engineering plan to deploy an operational SBSP system by 2050. We are forming an expert panel, comprised of leading SBSP experts and space and energy organizations, to gain a range of industry views.

"We will compare SBSP alongside other forms of renewable energy, to see how it would contribute as part of a future mix of clean energy technologies.

"We have also partnered with Oxford Economics, who have significant experience in the space sector and who will provide additional insight to the economic assessment of the system, and the benefit to the UK economy."

Source: UK Government

12 comments
paul314
Current solar panels (plus structure) come in about 10kg per installed kilowatt. Cost of putting something in geosynchronous orbit is currently well in excess of $10,000/kg. So that would be $100M per megawatt before worrying about assembly, pointing, transmission/reception, radiation hardening or even the cost of the panels. It's possible that weight could be reduced by a factor of 100 with thin films and magic, but a similar investment in batteries and other storage would seem likely to pay off sooner.

To reduce launch costs, you could put multiple arrays in lower orbits for what would likely be a smaller total system cost and greater global benefit, but astronomers would likely not be best pleased.
Eddy
I can see this going down really well with the NO 5G NO Microwave ovens brigade.
Matt
Worst idea ever! Extrapolate this idea until all countries have these units up and running. The earth can barely cope with the solar energy falling on it directly. We don't need to redirect more heat that would have otherwise missed. We would end up with low temp/high entropy heat that we would be unable to reject, like a power station with no cooling tower.
Why don't we get a giant space magnifying glass and kill ourselves like ants?
martinwinlow
@paul314 - https://theconversation.com/how-spacex-lowered-costs-and-reduced-barriers-to-space-112586 ... says it's nearer US$3k/kg (and that was a year ago). You wouldn't need a lot of the hardware associated with conventional ground-based modules (no gravity) and besides, there's no reason why - in time - the modules could not be manufactured in space, too.

My first thought was how to avoid conflicts with the microwave beam which would have to be pretty seriously powerful but I don't know enough about the tech. What would happen if an aircraft accidentally flew through it?

@Matt - I can't help feeling that the current use of fossil fuels is having a *massively* more serious negative effect on our atmosphere - along with all the pollution, to boot.
piperTom
A microwave beam with commercial power is also a weapon. I'm guessing the next Falklands war will be very different. If the Argentinians are comfortable with this idea, I won't complain.
paul314
@martinwinlow -- that $3k number, from all I could find, is for low earth orbit. Geosynchronous orbit costs a few multiples of that as long as we don't have space elevators. (And from a mass point of view manufacturing in space costs even more, because you have to bring up the manufacturing equipment as well as the material itself. You might have a win if you were using thin-film techniques, because you wouldn't have to make a finished device that could withstand the stress of liftoff.)
buzzclick
Nicola Tesla conceived delivering electricity wirelessly way before Asimov, just so you know. As for setting up a system of solar panels in space to deliver the amounts needed terrestrially, this sci-fi concept is out of this world. Instead of looking skyward for energy, one needs to look inward, where Tesla believed unlimited energy exists, and lightning is proof of that. The answer is right in front of us, not some pie-in-the-sky fantasy.
michael_dowling
paul314: Completely agree. Even SpaceX's promise to reduce launch costs by 90% with reusable boosters will still mean eye-wateringly expensive to put such a system into space. It would be FAR less expensive to construct solar farms in the Sahara with long distance power transmission to Europe.
Signguy
With millions invested and billions made for investors; this is a huge "industry" that maintains its power and profit through manipulating Congress and defeating legislation through millions in advertising against the people who want solar to be "free" from their control.
robert80
The comments below do a pretty good job of demonstrating why in a sane Universe somebody reviewing a grant proposal or corporate startup would simply be laughed out of the office or rejected out of hand. There is absolutely zero overlap in the cost-benefit spectrum between the factor of (maybe, possibly) 4 or 5 in mean insolation in orbit vs at points on the surface of the earth and the cost of putting things into orbit. One could build and install 100s of times as much surface collection capacity as one could ever afford to put into orbit, for at most a factor of hell, let's be generous to the point of science fiction, 10 gain relative to those ground collectors, WITHOUT worrying about the technical challenges of large area cells necessarily exposed to the solar wind, atmospheric drag, CMEs, and space junk in orbit. Then there is the simple fact that a GW-scale generator in orbit and transmitting to a kilometer square ground antenna (at some less than 100% efficiency) is receiving a kilowatt per square meter, making it a weapon of mass destruction even BEFORE focusing it down to where it delivers a megawatt per square meter to a circle some 20 meters in radius.

Simply stupid.