China Built a 246-Foot Tower To Test an Emerging Solar Power System (interestingengineering.com) 64
An anonymous reader quotes a report from Interesting Engineering: [T]he world is now one step closer to seeing operational space-based solar energy as scientists from China's Xidian University completed testing and inspection on a ground array built to collect space-based solar power. They conducted a successful test of the "world's first full-link and full-system solar power plant" on June 5, according to a press statement from the university. The space-based solar power plant is a 246-feet-tall (75 meters) steel tower built on Xidian University's southern campus.
In theory, the Xidian University power plant will connect to orbital satellites that will harvest solar power 24/7 due to their geostationary orbits, before beaming that energy down to Earth via high-frequency microwave beams. The power plant will feature five different subsystems aimed at developing space-based solar power arrays. Space-based solar power has great potential as it can collect energy continuously while sidestepping common problems such as bad weather and waiting for daybreak. However, hurdles do remain, such as assessing the effects of a high-frequency energy beam on communications, air traffic, and the well-being of nearby residents.
Xidian University's new ground station is part of a space-based solar power proposal called OMEGA, which stands for Orb-Shape Membrane Energy Gathering Array. The project was first proposed in 2014 by Duan Baoyan from the Xidian University School of Electromechanical Engineering and his colleagues. [...] China's OMEGA project, meanwhile, has successfully transmitted energy wirelessly as microwaves over a distance of approximately 180 feet (55 meters). This capability puts the project three years ahead of its original schedule, the university says in its press release. Still, Baoyan concedes that a lot of work is still required, and fully operational space-based solar power could still be years away.
In theory, the Xidian University power plant will connect to orbital satellites that will harvest solar power 24/7 due to their geostationary orbits, before beaming that energy down to Earth via high-frequency microwave beams. The power plant will feature five different subsystems aimed at developing space-based solar power arrays. Space-based solar power has great potential as it can collect energy continuously while sidestepping common problems such as bad weather and waiting for daybreak. However, hurdles do remain, such as assessing the effects of a high-frequency energy beam on communications, air traffic, and the well-being of nearby residents.
Xidian University's new ground station is part of a space-based solar power proposal called OMEGA, which stands for Orb-Shape Membrane Energy Gathering Array. The project was first proposed in 2014 by Duan Baoyan from the Xidian University School of Electromechanical Engineering and his colleagues. [...] China's OMEGA project, meanwhile, has successfully transmitted energy wirelessly as microwaves over a distance of approximately 180 feet (55 meters). This capability puts the project three years ahead of its original schedule, the university says in its press release. Still, Baoyan concedes that a lot of work is still required, and fully operational space-based solar power could still be years away.
First thought: (Score:4, Interesting)
Could it be used as a weapon too? Archimede's style?
Re:First thought: (Score:4, Interesting)
Could it be used as a weapon too? Archimede's style?
Sort of. Depends on how concentrated the microwave beam is.
Sigh... Wireless power.
Assuming that this thing can harvest useable amounts of electricity at a range of hundreds of miles - at present, they've done 55 meters, the inefficiencies are incredible. As well, probably should say goodby to a healthy hunk of electromagnetic spectrum the idea of beaming down enough energy to collect a GigaWatt of electricity will take many many GigaWatts, to approach that. Unless the beam is spread out over a large area - like kilometers, you definitely would not want to be in it's path.
Suffice to say, at a 50 percent efficiency - a couple GW will have to reach the ground.
Imagine if you will, something happening to knock the satellite off course a teeny bit. If the beam is concentrated, it won't be pretty.
Now imagine the strategic implications.
Rockets with bags of sand or little ball bearings could bring down a country's power system. This is even more vulnerable than a country building as few and as big nuclear reactor generating systems.
Even if it did work, humanity isn't peaceful enough to run such a thing. This gets written off to the endless parade of grant seeking, not to practicalities.
Re: (Score:2)
Meanwhile, back on Earth... 1GW solar farms are being constructed in non-desert areas:
eg. https://balkangreenenergynews.... [balkangree...gynews.com]
Re: (Score:2)
Meanwhile, back on Earth... 1GW solar farms are being constructed in non-desert areas:
eg. https://balkangreenenergynews.... [balkangree...gynews.com]
I'm not certain if you are trying to disagree with me or what. A Gigawatt of power being generated in a location is an okay idea. I prefer more localized setups for strategic reasons though - but that's a different subject. But transmitting power through space is a whole different animal.
Funny part is we're just picking up the solar power right on earth a few kilometers downwind of this satellite infrastructure system with it's incredible losses and dangers and vulnerabilities.
Re: (Score:2)
Re: (Score:3, Funny)
Even if it did work, humanity isn't peaceful enough to run such a thing. This gets written off to the endless parade of grant seeking, not to practicalities.
The idea is a longshot, but because it's China, they will actually try this out. They don't have to wait for people like you to issue a permit.
Re: First thought: (Score:2)
Re: (Score:3)
Even if it did work, humanity isn't peaceful enough to run such a thing. This gets written off to the endless parade of grant seeking, not to practicalities.
The idea is a longshot, but because it's China, they will actually try this out. They don't have to wait for people like you to issue a permit.
NASA proposed something like this in 2012 https://interestingengineering... [interestin...eering.com]
And we see why humans are so vulnerable to the big grift. I don't need to issue permits for crypto or other amazing devices either. People line up to get their money taken.
Re: First thought: (Score:2)
Is the overall efficiency even established? I was looking for a general number but couldn't find it. I agree this seems enormously inefficient. I'm assuming the microwave generation is via solar cells powering microwave generators. Being generous the panels themselves are 30% efficient, and then there's losses in the conversion to microwaves, then transmission losses, then collection losses on the ground, then losses converting the microwaves to usable electricity.
I'm certainly no expert here - are the lo
Re: (Score:2)
Is the overall efficiency even established? I was looking for a general number but couldn't find it.
If a person is transmitting a megawatt to something like a multi element yagi-uda antenna or a dish, mere microwatts show up at receiving station many kilometers away. It's not Apples to Apples comparison, but RF transmission and reception involve huge losses between transmitter to receiver. So yeah. Transmission of electromagnetic power happens every day, and has happened around here since our sun first ignited.
It's a good thing the losses are huge. Just imagine the Sun to earth situation if they were n
Re: (Score:1)
RF transmission losses are mostly one of focus. The size of the dish/array to focus the radio waves people use yagi antennas for is large, and unnecessary for what people like radio waves for. Doing this at microwaves will help that (although I agree the numbers still look crazy for antenna sizes you could build on earth and launch in a spacecraft), and the atmosphere opacity skyrockets as you move up to higher frequencies/sub-mm.
The atmosphere is pretty transparent at the peak of the Sun's energy distribut
Re:First thought: (Score:5, Interesting)
I'm no microwave expert, but I've read concept papers on this before. The approach that those papers favored was a huge receiving array: wires spread over square miles. For example, suspended over crops. The idea was that (a) the beam is far less concentrated, so not dangerous at all, and (b) aiming was less of an issue. IIRC, the theoretical efficiency of transmission was expected to be very high, in the 80% to 90% range.
Trying to target a powerful beam from geocynchronous orbit onto a small towers seems...suboptimal.
Re: (Score:2)
I'm no microwave expert, but I've read concept papers on this before. The approach that those papers favored was a huge receiving array: wires spread over square miles. For example, suspended over crops. The idea was that (a) the beam is far less concentrated, so not dangerous at all, and (b) aiming was less of an issue. IIRC, the theoretical efficiency of transmission was expected to be very high, in the 80% to 90% range.
I wonder what they are thinking 80 to 90 percent of? That number seems impossible to me, that even 80 percent of the beamed microwaves would ever reach earth.
>
Trying to target a powerful beam from geocynchronous orbit onto a small towers seems...suboptimal.
And how! Even using dish antennas, the radiated energy will be spread out pretty widely by the time it reaches earth. This is simple radio transmitter and receiver physics, nothing special except that instead of intelligence transmission and reception being the goal, power is the end product.
So over a short range, perhaps in the near field, and w
Re: (Score:2)
Could it be used as a weapon too? Archimede's style?
Of course!
Re: (Score:2)
There's defense like a good offense
Re: (Score:3)
Yes, absolutely. And you don't need any big towers for such a system that cannot easily be used as such a weapon. You build a big field of rectennas and your satellites can aim but not focus, so they literally can't be used to cook anyone/anything. You don't need a big tower, you need a whole shitload of antennas. This system looks like it's designed to catch power from one satellite in a focused point, which means they're envisioning a system which could be used as a weapon...
Re: First thought: (Score:2)
I wonder if you couldn't dual-purpose a large solar farm with rectennas (above?). You're already dedicating the land to power generation and it will have grid infrastructure.
Re: (Score:2)
There's new solar rectennas being worked on, maybe somehow they could be more than one kind of rectenna.
Re:First thought: (Score:5, Interesting)
Point a 100 MW beam at somebody's lake or reservoir and it will evaporate a lot of water quickly (about 40 L per second). 100 MW is roughly equivalent to the amount of sunlight hitting the Earth's surface in a circle with 370 m diameter (at the equator), and doubling that will cause a lot of problems pretty quickly.
Re: (Score:2)
Maybe that's specifically what china actually wants it for... making it rain.
You know, if I were trying to imagine an anti-satellite network for defending against potential weaponization of other satellites, it would look a lot like starlink... in that the numbers would be massive.
Re: (Score:2)
You know, if I were trying to imagine an anti-satellite network for defending against potential weaponization of other satellites, it would look a lot like starlink... in that the numbers would be massive.
Possibly, musk is really fkn it up though with low earth orbits that would naturally deteriorate in a few years to decades at most. What you reaallly need is a bigger cluster higher up, then you just detonate them and nobody is going to use space without playing Russian roulette for about 10 forevers.
Re: (Score:2)
If you take out some satellites destructively in the orbits you're concerned about, same.
Re: (Score:2)
If you take out some satellites destructively in the orbits you're concerned about, same.
Hell, we’re getting there already and only a few have been purposely blown up. In theory if you just disabled them without destroying them the risk of debris clouds would be lower, but who thinks of the earth when playing thermonuclear warfare?
Re: (Score:2)
This is a great idea. Let's boil the oceans along the continental US to get more rain.
Re: (Score:3)
Re: (Score:2)
The Mythbusters did a segment on Archimedes' idea. It didn't work even with modern mirrors.
Re: (Score:1)
Insane (Score:4, Insightful)
Are they insane?
hurdles do remain, such as assessing the effects of a high-frequency energy beam on communications, air traffic, and the well-being of nearby residents.
No kidding. Plus there's the cost of sending it up there, the fact that all the electronics must be space-worthy, maintenance is non-existent, geostationary orbits are very high (36000km)so focusing that beam into a neat dot will be impossible, the list of facepalms goes on and on...
How about simply building one in a local desert instead? The Gobi is immense.
Re: Insane (Score:1)
Re: (Score:3)
China is in the habit of dropping spent rocket stages that had been fueled with hypergolic fuels on villages. While they might well care about the interruption of communications and air traffic, I wouldn't count on them caring about the well-being of nearby residents.
Re: (Score:1)
Also once the hardware dies up there it's staying there for practically forever - unlike low level satellites (say, for Starlink), it's not deorbiting from atmosphere drag at all.
Re: (Score:1)
Re: (Score:3)
Right, cost is the big problem with this. Getting anything into geosynchronous orbit is crazy expensive. Which of these do you think will be less expensive?
A. Build a lot of satellites with solar panels and microwave transmitters. Put them on rockets and send them 35,000 km up. Build a huge ground station to receive the energy and convert it to electricity.
B. Install 5x more solar panels on the ground, along with enough batteries to eliminate variation in power.
Given the current relative costs of solar
Re: (Score:2)
What about ... (Score:3)
Re: (Score:2)
The microwave transmitter will have to turn off to avoid frying things passing under its path ... including aircraft incursions, bird flocks, etc. The beam will have to be fairly narrow to hit a target on earth from a 35,786 km geosynchronous altitude. The ultimate 440,000 Starlink constellation will have a satellite every 25 km or so in space each going around the earth in just 90 minutes. So most of the time, even with such a large constellation most of the satellites will not intersect a beam in spac
Re: (Score:2)
Do we even have technology to generate such amounts of microwave energy in a reasonably tight beam?
Re: (Score:1)
Before lasers, they invented masers - which are basically microwave lasers, so that's a solid yes.
Re: (Score:2)
Wonderful (Score:2)
I may be a paranoid skeptic but I have never felt comfortable with the idea of high power microwave beams transferring power from satellites to the ground. At least not without some proven fail safe system to keep it on target.
Beam spread is going to be an issue even if the transfer is by a maser which I think would be in the 8km diameter range from a geostationary orbital position but I am not a physicist so maybe this can be tightened up a lot.
Also, which communications satellite is going to get bumped
Re: (Score:2)
I don't see any strong reason that the power satellites need to be in geostationary orbit. Surely you only need a reasonably low delta-vee between transmitter and receiver, which you could perfectly well achieve by using satellites in a much lower E-to-W (as seen from the ground) flight path, possibly low enough that the low-mass/unit area energy collectors would take some of the existing "space junk" out. Or
Trying to remember which SF story features this (Score:2)
Anyone?
Re:Trying to remember which SF story features this (Score:5, Funny)
Star Wars: A New Hope (1977).
What happened to Alderaan was a tragic industrial accident, but for your strong central government to build a space-based power system that meets the needs of society, you've got to crack some eggs.
Re: (Score:2)
SimCity 2000 had these. About the time you got them was the same time that you discovered the cheat codes and made a giant robot spider attack your city.
Re: (Score:2)
found it with google in about 15 seconds [wikipedia.org]
HTH HAND
Re: (Score:1)
75 Metres (Score:1)
Just a few more tiny steps (Score:2)
They've managed to beam power 180 feet, 60 meters basically.
So far, with the tech they have right now they couldn't beam power from the top of their tower to the ground, much less from the 22 THOUSAND MILES (36k km) of geostationary orbit.
Did "China" build it, or a university in China? (Score:5, Interesting)
It's a subtle bias, but the results are consistently pro-Beijing and anti-Western.
Solar is cheaper than nuclear UNLESS (Score:3)
Now nuclear becomes the cheaper option.
Did anyone do the math (Score:2)
The math may very well work out in space-based solar's favour, but it does need to be checked.
Re: (Score:2)
on whether adding energy to the Earth system from solar energy that would otherwise have passed by Earth in space will actually help cool the Earth's surface and atmosphere, by displacing e.g. coal power? The math may very well work out in space-based solar's favour, but it does need to be checked.
Let’s see, the earth gets 173,000,000,000,000,000 W of solar energy from the sun, and an additional 100mW is not even a billionth more. It’s about the difference not having a few clouds would make.
Re: (Score:3)
Humans consumer 18 Terrawatts from all sources. 18,000,000,000,000 W
Let's imagine about 55% of that is decided to come from this amazing new energy source, to decarbonize. So, 10,000,000,000,000 W
So now we have
10,000,000,000,000 W
/
173,000,000,000,000,000 W
So 1 part in 17,300. Starts to look a little more significant, given that the energy imbalance due to increased greenhouse gases is also only a small fraction.
Re: (Score:2)
Re:Did anyone do the math (Score:4, Interesting)
Re: (Score:2)
Nothing New (Score:2)
Gundam 00 (Score:2)
In the gundam series Gundam 00, the world had switched to solar arrays which beamed energy down to stations which was then distributed out to the masses. This seems the first step in that process.
Also in Gundam 00, the world was fractured into three economic blocs with China being the head of the Human Reform League. Their current political process of suppressing dissent and everyone conforming to one ideal seems also to be a first step in that process.
If someone could start work on the gn drives which powe
Don't think this will work; alterior motive? (Score:2)
2. To make this practical, as well as cost-effective, wouldn't you have to have a gigantic array of solar panels in orbit?
3. Aside from the above, how much of that power do you lose from the beam between orbit and the ground?
I can't see this as a viable idea. Furthermore, this being China, it's either all bullshit, or there's some alterior motive involved, like it being an array of space-based weapons of some sort. Would these be powerful enough to
Space-based solar power (Score:1)
Meh. (Score:2)
It's been done [damninteresting.com].
“There is no Master but the Master" (Score:2)
"satellites that will harvest solar power 24/7 due to their geostationary orbits, before beaming that energy down to Earth via high-frequency microwave beams. "
“There is no Master but the Master, and QT-1 is his prophet.”
Dual use technology (Score:2)
Now witness the power of this fully armed and operational power station!!