back to article China starts testing tech to harvest solar energy from orbiting panels

A Chinese ground-based facility for converting solar energy bounced to Earth is scheduled for completion by the end of 2021 and has already conducted energy transfer tests up to 300-meter altitudes, a key project member told state-run media China Science Daily. The project member, Zhong Yuanchang, is a professor at Chongqing …

  1. ianp5

    I hope this is energy that would've been absorbed by the earth anyway. If it's not then it's adding to global warming!

    1. Pascal Monett Silver badge

      By definition that is not the case. The solar satellite will be hundreds of miles above the planet, so it is soaking up energy that has missed us completely.

      However, I do believe that it is better to have a solar satellite than a raft of coal-based power stations that spew continuously into the atmosphere.

      What I am curious about is how well they are going to control the retransmission of power. I really would like this tech to work, but I'd also rather not be fried walking the dog.

      1. Anonymous Coward
        Anonymous Coward

        Hot dog?

        :)

    2. Christoph

      No. The energy just radiates back into space.

      It's like the difference between heating a house and insulating a house. If you heat a house you have to pump in energy all the time - when you stop it cools down. Pumping in energy from Solar Power Satellites doesn't do long term heating.

      If you insulate a house it stays warm without any extra energy input. Climate change is driven by CO2 and Methane trapping heat and stopping it radiating to space, not by individual energy inputs.

      The power input from the sun is vastly greater than all the power generated by humans, and that is what is trapped and causes climate change. Extra heating from satellite power is far too small to notice.

      1. veti Silver badge

        "Too small to notice" is exactly what our forebears used to say about all kinds of pollution when thinking at a planetary level.

        Turns out, these things are cumulative.

        The sun hits us with about 175,000 TW of power. China currently has something over 2 TW of generating capacity, and there is every likelihood that figure will double within about 30 years. If we assume that the processes of energy transport and conversion at the receiving end are likely to be less than perfectly efficient, then if China went over wholly to this tech, we could be looking at as much as 10-20 TW being added from China alone.

        Okay, it beats generating the power from coal and gas. But it's not nothing.

        1. DS999 Silver badge

          The world produced 14420 Mtoe (million tons of oil equivalent) in 2020 - and that's the amount of energy in what was produced, not what was actually extracted after inefficiencies. At 11.63 TWh per Mtoe that ends up about 19 terawatts continuous - or slightly more than .01% of the total amount of sunlight falling upon the Earth.

          If this endeavor was successful on such a grand scale as to replace all other forms of energy production (hard to see how it could be better than solar panels on top of your roof, for instance) we could afford the power to make and orbit mirrors to reflect off enough to compensate for the additional power we were sending down - reducing the solar insolation at the poles or various locations of open ocean far from land where it won't negatively affect human or animal life. We could even go above that to compensate for global warming, and/or power schemes to remove carbon from the atmosphere.

          There's zero reason to worry that if something like this was so successful it would make global warming worse. Instead, having so much power at our disposal and a demonstrated ability to build massive orbital structures would practically guarantee we could eventually reverse global warming.

  2. Adelio Silver badge

    Hope

    Although I am ever hopeful after I put my cynical hat on i doubt the UK will do more than "investigate" solar power from orbit. All talk, little action seems to be the UK's mantra.

    When you think that Russsian income is not that much different to the UK and we appear to spend almost nothing in these new technologies.....

    It would be nice if politians could get of their ar*ses and actually do something. But then after the fiasco of Brexit with this super deal that Bojo failed to negotiate and has been trying to squirm himself out of everr since....

    1. BristolBachelor Gold badge

      Re: Hope

      There's a simple solution. Borrow £5m. Invest £4m in starting up, marketing, brochures, website, etc. "Invest" £1m in donations to conservatives. Sit back and watch the investments/ contracts come rolling in

    2. Irongut Silver badge

      Re: Hope

      Not to worry, they'll put Baroness Dildo in charge and she'll spend loadsamoney on a app to tell you when the power satellite is overhead. Of course it won't work but that's because there will be no money left for an actual satellite or a rocket launch to put it into orbit. But at least all Boris' chums will get paid so that's ok then.

      More tea vicar?

  3. Denarius Silver badge

    problem

    So geosynchrous orbit gets more crowded. There will still be multiple 80 minute blackouts a year as the orbiting stations are eclipsed. One wonders if the old concept of a few very large, possibly inhabited geosynchrous stations serving large areas and connecting to each other might make for a less crowded sky, as well as hardware that can be upgraded as technology changes. Add comms to orbiting power stations means single platform, multiuse with no station power issues, mostly.

    However, more energy will be sent to Earth. Not a lot compared to total solar budget, but the panic merchants need something to fear

  4. BloggsyMaloan

    >Solar power collected in space has the advantage of being unaffected by weather

    Is transmission of energy back to Earth also unaffected by weather?

    1. Blank Reg Silver badge

      yes it is, though using the right frequencies and with a powerful enough signal you can overcome some of that. But then with such a powerful beam the consequences of missing your target would be catastrophic. It's just a dumb idea and a waste of time.

      1. BristolBachelor Gold badge

        The plans I've seen have about 1kW/m² on the Earth's surface, similar to what you'd get from the sun anyway. Mispointing just means you lose the power.

        The antenas to receive this are very efficient, and only need to be a few dipoles spaced apart. You could have a nice flower meadow growing around them.

        1. Blank Reg Silver badge

          Recommended exposure limits for EMF are usually in the low 10's of W/m², so we're looking at as much as 100 times higher here.

          https://www.canada.ca/en/health-canada/services/publications/health-risks-safety/limits-human-exposure-radiofrequency-electromagnetic-energy-range-3-300.html

          Table 6 would apply when the beam is on target, table 5 when it wanders over your neighbourhood.

      2. John Brown (no body) Silver badge

        The consequences of missing the target are only catastrophic if the death ray hits anywhere other than one of your enemies.

        I'm a little surprised El Reg did allude to China building death rays in the guise of "clean, green energy" somewhere in the sub-head.

  5. WaveyDavey

    Beams

    Didn't Charles Stross rename the power transmission beams from the satellites to the ground station? Orbiting Death Rays wasn't it ?

    1. Anonymous Coward
      Anonymous Coward

      Re: Beams

      Think of it as a sort of pre-cook facility for the Zombie invasion....

  6. M. T. Ness

    An exercise only.

    It seems unlikely that such a system can be cost effective.

  7. Fruit and Nutcase Silver badge
    Linux

    Roast Vulture

    Will we see Vultures and other flying birds dropping from the sky - ready cooked?

    --> Penguins (and Turkeys) should be safe, unless there is an errant satellite

  8. batfink Silver badge

    If it was me...

    I'd also be putting the receiving station 45 minutes' drive from where I was sitting.

  9. Anonymous Coward
    Anonymous Coward

    Er, isn't this a weapon ?

    Sorry, but a way of focussing gigawatts of power into a few tens of square metres ?

    Not sure I'd entirely trust it myself ....

    1. Adrian 4 Silver badge

      Re: Er, isn't this a weapon ?

      If it can be used as a weapon, then maybe all governments will want to invest in it.

    2. Anonymous Coward
      Anonymous Coward

      Re: Er, isn't this a weapon ?

      *THIS*.

      Deathray for sure.

      It makes no financial sense to place those up in space, I think all such projects are violations of the space arms treaty disguised as "solar power" projects.

  10. Adrian 4 Silver badge

    Safe receivers

    Large solar cells and microwave transmission seems an inefficient way to do it : you've got two conversions and neither is very efficient.

    A solar oven seems a better way : many moderately sized reflectors which together focus on a single area. Failure of a few of them tom track would not be dangerous : it would only double the sunlight on the accidental target.

    The intentional target could be in the sea, boiling seawater to make steam and simultaneously desalinating while allowing a large safety border.

    The large passive reflectors would be slow to re-orientate, making it difficult to use as a weapon.

  11. SusiW
    Mushroom

    Side Lobes?

    Hmm. The thing about radio transmission (microwave, etc) is that Tx antenna/horns produce side lobes of energy out from the side of the main directed 'beam.'

    There's a term in microwave (directed energy) weapons development called "Fratricide." This is where those side lobes fry your nearby brothers(and sisters)-in-arms and damage electronic systems.

    Careful tuning of the Tx aperture/antenna can reduce this lobing, but never completely remove it.

    Just wondering how all that other expensive SpaceTech will deal with the extra interference from these, <cough!> "Totally Peaceful" Power Systems?

  12. Elledan Silver badge

    Doesn't add up.

    Consider the costs of getting all of that mass up in orbit, with essentially zero way to maintain or repair it, with the conversion losses of going from light to electricity, to microwaves, then back from microwaves to electricity. This is a project that would be hyper-expensive, prone to complete failure and with only a fraction of the ROI of building, say, a nuclear power plant, whether fission or fusion (research or commercial).

    It's a nice prestige project for China, but its practical use is roughly zero.

  13. DJ
    Coat

    Hmm...

    "Solar power collected in space has the advantage of being unaffected by weather or that pesky thing called "night"."

    This is not my area of expertise, but it seems to me that for this to work, the gizmo in the sky must be geosynchronous above the receiver gizmo.

    If that is the case, won't both objects be in the dark at night?

    Mine's the one with telescope that doesn't see as many stars at night as it used to in the pocket.

  14. John Brown (no body) Silver badge

    Crackerjack!!!

    "in the early 1970s Peter Glaser received a patent for a design to transmit power from satellites to Earth using microwaves."

    Oops, sorry, Wrong Peter. Sometimes, ingrained and instinctive reactions are hard to overcome.

  15. JimmyPage

    This must be the feudal landowning classes wet dream ...

    Imagine claiming the land under the area of reflected energy and kicking all the peasants off it ?

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