[HN Gopher] Beaming Clean Energy from Space
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       Beaming Clean Energy from Space
        
       Author : danboarder
       Score  : 17 points
       Date   : 2022-11-02 16:22 UTC (6 hours ago)
        
 (HTM) web link (www.caltech.edu)
 (TXT) w3m dump (www.caltech.edu)
        
       | wrycoder wrote:
       | This same tech was on the cover of a 1971 IEEE Spectrum magazine.
       | I don't see any advancement since then.
        
         | MichaelZuo wrote:
         | 100 km of atmosphere in the way of any 'beaming' makes the
         | economics unviable even with recent drops in launch prices.
         | 
         | It will likely have to be assembled in space from materials
         | mined in space to ever work out.
        
           | avmich wrote:
           | Microwaves pass through atmosphere with negligible losses.
        
             | MichaelZuo wrote:
             | The losses certainly are not negligible, they're >> 10%.
        
               | fnordpiglet wrote:
               | That's why Bruce banner was experimenting with gamma
               | rays. It's a shame what happened to him.
        
         | LargoLasskhyfv wrote:
         | Roland Emmerich's first from 1984!
         | 
         | https://en.wikipedia.org/wiki/The_Noah%27s_Ark_Principle
        
         | ZeroGravitas wrote:
         | There's been all sorts of improvements since then, reusable
         | rockets, better PV, the list goes on and on.
         | 
         | Still doesn't make any sense because alternatives, like ground
         | based solar and wind have also advanced considerably.
         | 
         | In fact, if you use the best available alternative source of
         | electricity as the benchmark, it's regressed noticeably since
         | the 1970s.
        
       | avmich wrote:
       | https://caseyhandmer.wordpress.com/2019/09/20/no-really-spac...
       | 
       | (from linked previous post)
       | 
       | "My view is that space-based solar power is impossibly expensive
       | and will never be used on Earth."
        
         | ZeroGravitas wrote:
         | > at the end of the day, power is cheap and rapidly getting
         | cheaper on Earth, while it remains expensive in space.
         | 
         | Only a couple of years max before this becomes obvious to
         | everyone so if you have any mad schemes that rely on high
         | energy prices then your window of opportunity to land some
         | funding is closing.
        
         | tectonic wrote:
         | I disagree. The currently envisioned approaches are impractical
         | due to in-orbit assembly needs, but there are other options.
        
         | superkuh wrote:
         | I agree. In radio the size of the aperture across which the
         | currents flow is inversely proportional to the size of the
         | antenna main beam. The pattern is literally the fourier
         | transform of the currents. The bigger the smaller. There's no
         | getting around needing to have a giant antenna surface (or
         | array).
         | 
         | In order to have the required extremely tiny main beams (high
         | gain), to not instantly lose most of the power to spreading
         | losses, LEO beamed power at reasonable microwave frequencies
         | requires ~5km wide aperture.
         | 
         | We cannot build 5 km things in space yet. It is not really
         | something worth discussing till we're doing that regularly.
         | Space based power isn't that much more available than ground
         | based so there's not much value added to the huge increase in
         | cost orbit requires.
        
           | avmich wrote:
           | Henry Spencer (https://en.wikipedia.org/wiki/Henry_Spencer) a
           | couple of months ago run a presentation of current state in
           | space power. Land antennas (rectennas) were in this size,
           | ~5km diameter, made mostly from chicken wire. Cheap, and you
           | can still grow vegetables or anything under it. Not much risk
           | walking under it either. Space antennas are an order of
           | magnitude smaller, ~250 meters (for gigawatt-class power
           | stations).
           | 
           | To me, this all seem to need a lot of data and some careful
           | calculations :) .
        
       | lawrenceyan wrote:
       | Modular, decentralized, adaptable, no single points of failure,
       | resilient to degradation, and cost-effective all while providing
       | superior performance?
       | 
       | This is amazing! Are there any downsides? I can't think of any
       | off the top of my head.
        
       | rgmerk wrote:
       | The only place this might make sense is at high latitudes where
       | solar power is essentially unavailable for months on end when
       | demand is highest.
       | 
       | In temperate and tropical latitudes it's unlikely to be
       | economically competitive with solar panels on the ground.
        
         | danboarder wrote:
         | 24-hour or near 24-hour power delivery would be a big advantage
         | to these space-based solar systems, compared to only mid-day
         | daylight for terrestrial solar.
        
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       (page generated 2022-11-02 23:01 UTC)