[HN Gopher] A Different Kind of Solar Power Attracts Attention
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A Different Kind of Solar Power Attracts Attention
Author : prostoalex
Score : 27 points
Date : 2022-05-02 16:00 UTC (3 days ago)
(HTM) web link (www.wsj.com)
(TXT) w3m dump (www.wsj.com)
| ncmncm wrote:
| Concentrated solar costs 3x as much as PV if you want to make
| electricity.
|
| But sometimes what you need is heat, and concentrated solar does
| it fine. For some reason not elucidated, nobody seems to be using
| it for industrial process heat, e.g. making cement.
| olivermarks wrote:
| http://www.brightsourceenergy.com/coalinga#.YnRFv-nMLUJ
| ncmncm wrote:
| Great, using solar to help put fossil carbon into the
| atmosphere.
| olivermarks wrote:
| That experiment ended in 2014 I think
| haspoken wrote:
| https://archive.ph/GR2Ni
| pintxo wrote:
| > Another innovation suggests that artificial intelligence could
| make CSP more competitive. Heliogen Inc., a CSP company backed by
| Bill Gates, uses computer vision to track the sun and continually
| adjust the mirrors in a CSP plant to maximize the concentration
| of sunlight.
|
| Is this a journalist not getting it? Why would we need computer
| vision to track the position of the sun?
|
| > That takes some of the complexity out of building a CSP system,
| which lowers construction costs. In current systems, mirrors have
| to be painstakingly installed in the best possible position. Even
| then, the ground can shift and stop concentrating the sunlight as
| effectively, according to Bill Gross, Heliogen's CEO and founder.
|
| Ok, maybe it's more about the continuous optimization of the
| mirror positioning.
| lscharen wrote:
| Given the existence of passive solar trackers that work
| mechanically, it's really hard to see how a complicated active
| tracking system could possible outcompete for a PV system.
|
| However, the company in the article is involved in concentrated
| solar power, so perhaps the situation is different enough to
| warrant such a system. I can _sort of_ see how there could be a
| feedback loop where changing ambient temperatures and radiative
| heat from the tower might effect the reflective array in
| complicated ways that would make it hard to maintain a very
| tight focus point. And, if tightening the focus point of the
| array can double or triple the incident W/m^2, maybe that gets
| past some sort of pass/no-pass temperature threshold that
| allows for higher overall energy conversion....
| [deleted]
| tlb wrote:
| It's hard to adjust one mirror at a time, because 1000 other
| mirrors are reflecting at the same spot. And you can't put a
| camera on the target to look back at the mirrors, because it
| would get melted. And some errors are harmless, like aiming too
| high, but aiming too low can melt the tower.
|
| And you have to do all the aiming with cheap linear actuators
| that aren't very stiff, so wind affects everything.
|
| I dunno about AI, but it is a problem that programmers have
| struggled with so it might be worth a try.
| manholio wrote:
| > And you can't put a camera on the target to look back at
| the mirrors, because it would get melted.
|
| So just put it behind a heavy metalized filter that reflects
| over 99% of the incoming energy? And suspend the whole
| assembly about 1 meter in front of the target on a metalic
| post so it can cool down in the air. Or rather, a number of
| such assemblies so you can maximize incident energy over the
| entire target.
|
| Optimizing that does not sound like a deep learning problem,
| just a classic computer vision algorithm.
| londons_explore wrote:
| Or just put the camera somewhere else. Then point one
| mirror at a time at the camera (therefore, it only seex 1x
| sunlight) to do angle calibration, and then aim that mirror
| back at the proper target and calibrate the next.
| tlb wrote:
| Maybe. Just remember that an extra 1% of efficiency is
| worth 1% of the billion-dollar project cost, so there's
| pressure not to have sensors blocking even a tiny part of
| the view.
| zardo wrote:
| If actuators to keep the mirrors oriented correctly really do
| blow the budget then this sounds like a dead end.
| tlb wrote:
| It's not black & white. You want to use the cheapest
| actuators you can get away with. If clever software lets
| you use less precise actuators, it's a big win.
| buescher wrote:
| You could have position feedback on the mirrors and
| periodically calibrate the transfer function of mirror
| position to focus point at night.
| always2slow wrote:
| I bet the mirror will heat up during the day and your night
| calibration will be off.
| 29athrowaway wrote:
| It would be better to concentrate all of the light into a space
| mirror facing the Kremlin.
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