Look! Up in the sky! Proof of concept for satellites beaming energy to Earth!
- Reference: 1668065587
- News link: https://www.theregister.co.uk/2022/11/10/esa_space_based_solar_power/
- Source link:
The ESA's space-based solar power (SBSP) initiative created a preparatory program called SOLARIS to test [1]beaming solar power from satellites to Earth via microwaves. SOLARIS was the agency's effort to investigate what technologies are needed to realize the idea, and the feasibility of using them.
The ESA spent 2022 working on various aspects of [2]SOLARIS , including publishing a pair of cost/benefit analyses and holding an [3]industry day with presentations from the space agency and its commercial partners, including Airbus.
[4]
The ESA found SBSP feasible as a complementary power source to terrestrial renewables. And in September, Airbus demonstrated that it could [5]use microwaves to transmit power at a distance of 36 meters (118 feet), which it used to light up a miniature city. It's not exactly Alderaan, but it's a start.
[6]
[7]
Airbus's demonstration may be precisely what's needed to tip the scales in favor of more money for SBSP, if ministers aren't already convinced.
"Now that we have successfully tested the key bricks of a future space-based solar power system on a small scale for the first time, we are ready to take Power Beaming to the next level", said Airbus research project leader Yoann Thueux.
[8]
While those results are encouraging, SOLARIS can't do more without more funding from the ESA's Council of Ministers, which will soon stage its [9]annual meeting at which it hears requests for cash.
Using orbital solar panels to beam energy to Earth using microwaves isn't a new concept, either in fiction or reality. NASA has explored the idea, as have Japan's space agency, the US Navy, UK Space Energy Initiative, universities and private companies.
So far, China appears to be [10]leading the world in SBSP , having already tested the capabilities of a ground-based receiver using balloons floating at altitudes of up to 300 meters, and plans for higher altitude tests.
Space-based fantasy, or something more?
There are a lot of reasons why SBSP is exciting: It could help the world meet net zero goals, is able to deliver power 24 hours a day, captures solar energy far more efficiently since it's at a much higher altitude, and could minimize the amount of space needed to harvest energy in comparison to standard terrestrial solar arrays.
But the ESA admits space-based solar power satellites are not currently feasible. Previous ESA studies and similar efforts from other agencies "have found no principal technical showstoppers but prohibitive challenges to make the concept economically viable due to high launch costs and engineering challenges."
[11]
Take solar-collecting satellites, for example. In order to make them efficient enough to be worth the hassle, a single satellite would need to be somewhere in the neighborhood of a kilometer or more across. It would be visible in the sky like a small moon – too big to be a space station. That would give the satellite the ability to beam around 2GW of power down to Earth – the same amount generated by a terrestrial nuclear power plant.
But get this: In order to grab that amount of power, the receiver on the ground may have to be [12]ten times that size . For a comparison, the 2GW Pavagada solar park in India occupies [13]approximately 53 square kilometers.
However, unlike arrays of terrestrial solar panels, the SBSP microwave receiver would allow light and rainwater to pass through. That means the land underneath could still potentially be available for agricultural use.
Ground-based concerns aside, it's unlikely such satellites could be practically built with today's tech. Noting that it took dozens of launches to build the International Space Station, the ESA said it "would likely require an order of magnitude more launches to assemble a solar power satellite that weighs in at many thousands of tonnes."
Rather than looking at that as a sign that SBSP is a waste of research funding, the ESA said that the necessary research would be a boon for the larger space industry.
"Photovoltaic and power conversion efficiency, on-orbit manufacturing, assembly, and servicing, and deployable antenna developments" would all be developmental side-effects, the ESA said.
For those worried these efforts could deliver wildfire-starting space lasers, it isn't. Microwaves, the ESA notes, operate at a non-ionizing frequency that won't cause cellular damage. Beyond that, models of microwaves designed for SBSP use have a maximum power density of approximately 250 watts per square meter at the center of the beam, while a person standing near Earth's equator at high noon would be blasted with four times that.
Still, that's just one more thing the ESA said will be part of the many considerations and "further tests" needed to get the agency to the point where it sees SBSP as something that could meaningfully contribute to Europe's clean energy goals. "Only if, and when, these conclusions are reached would a proposal potentially be made to progress to an SBSP development project," the ESA said.
In other words, don't start looking skyward for the makings of an Earth-orbiting Dyson swarm just yet. ®
Get our [14]Tech Resources
[1] https://www.esa.int/ESA_Multimedia/Images/2022/11/Wireless_power_from_space
[2] https://www.esa.int/Enabling_Support/Space_Engineering_Technology/SOLARIS/SOLARIS2
[3] https://www.esa.int/Enabling_Support/Space_Engineering_Technology/SOLARIS/SOLARIS_Industry_Day
[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2Y2zZ2SlyfZv-NnKyK3h-pQAAAI8&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[5] https://www.airbus.com/en/newsroom/news/2022-09-solar-power-beams-a-step-towards-cleaner-energy
[6] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44Y2zZ2SlyfZv-NnKyK3h-pQAAAI8&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[7] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33Y2zZ2SlyfZv-NnKyK3h-pQAAAI8&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[8] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44Y2zZ2SlyfZv-NnKyK3h-pQAAAI8&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[9] https://www.esa.int/About_Us/Law_at_ESA/Ministerial_Council_Meetings2#:~:text=The%20Council%20is%20ESA's%20governing,the%20Council%20every%20four%20years.
[10] https://www.theregister.com/2021/08/17/china_orbiting_solar_panel_tech_tests/
[11] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33Y2zZ2SlyfZv-NnKyK3h-pQAAAI8&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[12] https://www.esa.int/Enabling_Support/Space_Engineering_Technology/SOLARIS/SBSP_overview
[13] https://www.power-technology.com/projects/pavagada-solar-park-karnataka/
[14] https://whitepapers.theregister.com/
Re: You also get the problem ....
Nice idea, but I'm guessing that beaming energy from a geostationary orbit would require an order of magnitude in tightening the beam so as to not to have a 200km-wide reception area.
If said satellite is is low Earth orbit, it's likely a lot easier to hit a (relatively) small region on the ground.
But you're right, it is also very much more at risk of getting shredded by space junk.
Re: You also get the problem ....
If said satellite is is low Earth orbit, it's likely a lot easier to hit a (relatively) small region on the ground.
It would be if it wasn’t zipping past at 17,000 mph.
Re: You also get the problem ....
The original planning for SSPS by Philip Glaser and Gerard K O’Neil in the 1970’s proposed building the satellites from materials mined on the moon and launched to geostationary Earth orbit by electromagnetic rail launcher. The argument was that it would be more economical and less disruptive than launching massive rockets from Earth. The concept still has merit.
Mad dogs and Englishmen
Go out in the mid-day sun...
I wonder how many of those 250W/m^2 are absorbed by human skin? It might not light fires, but are we seeing a new economy-sized area denial weapon?
Re: Mad dogs and Englishmen
The article clearly states that, standing at the equator, you get blasted by four times that amount of energy.
There doesn't seem to be much economy denial going on there right now.
Re: Mad dogs and Englishmen
...because the equator is famous for hosting the worlds most developed economies?
Re: Mad dogs and Englishmen
The article clearly states that, standing at the equator, you get blasted by four times that amount of energy.
Kinda. So insolation is around 1000W/m^2, so you'd be 'blasted' by 1250W/m^2 in total. Curious exactly what frequency they're using though because water vapour is notorious for absorbing microwaves. Plus the potential for interfering with, or damaging anything else using those frequencies. Still has potential for doing fun things, like stimulating clouds, jamming or enhancing microwave-using stuff.
There's also the cost/benefit, ie utiliising the power would need an enhanced solar farm in the beam spot which would basically end up 25% more efficient than a regular panel.
It's a good thing the South African government isn't building this. It would cost about the same as a Dyson sphere and provide the same amount of power as 2xAA cells. Compare Kusile power station.
Every government is useless. Everybody accepts this. Why people vote for more of it is beyond me.
Douglas Adams got it right
Otherwise the wrong lizard might get in.
Microwaves, the ESA notes, operate at a non-ionizing frequency that won't cause cellular damage
The dead cat in my microwave oven tends to disagree. Seriously though, 2GW spread over 10 square kilometers is in the same order as regular solar radiation on European soil, on a sunny winter day. Or did I miscalculate something here? I'm slightly underwhelmed by the fact that this microwave beam wouldn't even heat my porridge.
The fact that it would be additional to the photovoltaics. They could easily mount the microwave receivers above photovoltaic panels, doubling the power.
They could easily mount the microwave receivers above photovoltaic panels, doubling the power.
Nope. That would shadow the solar PV panels. You'd need to make a panel that's sensitive across the normal solar spectrum and the microwave band, otherwise you could end up just reducing the effectiveness of a plain'ol panel.
With solar panels of that size in space wouldn't they just act as a solar sail?
If they do then it would make station keeping an interesting problem.
Re: Solar sail
Light pressure is tiny and only makes a big difference to really thin films. You are looking for a massively huge difference here. That 1km satellite looking like a small moon gives an altitude of about 100km. At 100km the vacuum of space is so thick that air resistance would drop a lead brick before it completed a single orbit. A more realistic altitude would be 300-500km. A huge surface area satellite would still need a large collection of ion thrusters to remain in orbit. Their required mass, the mass of the propellant and the support structure would swamp light pressure and we haven't even got to cooling yet. The supplied figures assume magic >80% efficient conversion of sun light to microwaves. Even with that magic the waste heat would be huge and the heat sink to stop the satellite melting would add another layer of mass.
Has anyone seen real numbers for SOLARIS? I followed some of the links and all I found were hand-wavy power-point slides. No proposed satellite orbit+altitude, no figure for overall conversion efficiency. The old proposals were GEO satellites that had to beam power tens of thousands of km but could hit a single receiver all day and night. This sound more like a SSO constellation. The satellites remain in sun light all the time but can only hit targets near dawn/dusk. Similar economics to Starlink: profitable when the satellites pass over rich Americans with monopoly priced broad band but the satellites spend much of their time over regions sparsely populated by poor people.
Problem
The problem would be the loud moaning of the Karens, they think that 5G causes cancer, so what will they say to orbiting microwave ovens beaming death rays at them?
Redemption for Tesla?
No - the bloke
More importantly than providing power, how much would it cost for my dreary English seaside town to have a whip-around, knock one of these together and turn our bit of the coast into the costa-del-England?
"That means the land underneath could still potentially be available for agricultural use."...
https://www.wired.com/story/growing-crops-under-solar-panels-now-theres-a-bright-idea/
Um
The major source of global warming is actually the sun's energy. Without it our greenhouse gases would have nothing to work on.
I know, let's beam down MORE solar energy!
Funny how nobody has made the calculation to see how much of it also gets retained in the greenhouse.
To be fair, nuclear also suffers the same problem; we just beam it out from a reactor core instead.
But I do wonder how much greenhouse shit gets belched out by the satellite's manufacture and by the rocket that blasts it up there, and whether it will really recoup all that over its operational lifetime.
I would have preferred an elephant-in-the-room icon, but there you go.
On the plus side..
Sounds like we could save some money on our home energy bill by just plating up our food, sticking it on the Window sill and waiting while it's microwaved.
Re: On the plus side..
I confidently predict a fashion for matte black dishes. Even the present solar grunt is enough to fry an egg placed on black tarmac.
Add a glass lid, and you create a tiny greenhouse microclimate for good measure.
Look, don't laugh, I have seen guys wrap a fish in kitchen foil and cook it on the exhaust manifold of their car. And more realistically, solar barbecues complete with parabolic plastic mirror are a thing. In fact I'll give away a free mirror with each casserole dish. There is a market out there for sure.
This may be a silly question but if you put a multiple square kilometres of solar panels in geostationary orbit, where do their shadows fall and, if on the earth's surface, how much does that reduce local surface temperature?
How many satellites are they proposing - 100s to make it economic one assumes? What about spending that massive investment on solar panels and putting them on every house roof for free and gaining the same benefit?
The problem with wind and solar is that you can't rely on its output so you need to spend far more than just the cost of the turbines/panels buying batteries which makes solar economically unviable.
If the panels are in space there is no weather and no night-time. I assume the beamed energy will be able to penetrate clouds of course.
If you can bypass the lack of reliability by putting reflectors in space, that solves the problem.
Whether this is cheaper than building batteries or waiting until something actually viable comes along, I don't know.
You also get the problem ....
.... of your huge orbiting solar panel becoming a target for every little piece of junk that is floating around up there. You're certainly not going to be able to dodge incoming junk the way the ISS (and other satellites) can.
Probably the only way to avoid that issue (or at least greatly reduce it) would be to use GEO. And that just increases the fuel cost for getting it up there.
Of course what you really want to do is visit a NEO asteroid, and (somehow) shift it into Earth orbit. Then you just need to solve mining/smelting/manufacturing/construction in space and Robert's your Mothers brother!
I think I should patent the idea!