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Heliogen, backed by Gates, says it has achieved a solar breakthrough

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Re: Heliogen, backed by Gates, says it has achieved a solar breakthrough

#61

Post by pbhjpbhj »

ben509 wrote: post #42

Another interesting problem this might solve is birds. Yes, domestic cats kill orders of magnitudes more birds, but that argument a. depends on relative scale that people don't grok, and b. coming from an energy company reinforces the preconception that they're callous. Add radar and a sufficiently smart AI, and they could turn a PR problem into a marketing pitch by showing birds flying through unscathed while the mi…

If you can track individual birds like that I'd have thought you could do targeted scaring to deter the birds before they get fried. Moving mirrors quickly enough seems like it would require quite significant adaptation of the apparatus?

Re: Heliogen, backed by Gates, says it has achieved a solar breakthrough

#62

Post by mlyle »

gonzo41 wrote: post #18
stinky613 wrote: post #16

Earlier quoted context omitted.

I think that would depend on how precisely they need to be calibrated, right? IIRC even military GPS is still only accurate to within a few feet.

Survey quality GPS is able to have centimeter accuracy. https://en.wikipedia.org/wiki/Real-time_kinematic

But centimeter accuracy is of limited value. It doesn't tell you how the mirror base inclination has changed due to subsidence and thermal effects.

If every mirror has drifted a small angle, and you're trying to point them all at a very small target-- it's hard.

Re: Heliogen, backed by Gates, says it has achieved a solar breakthrough

#63

Post by mlyle »

localhost wrote: post #44
Waterluvian wrote: post #23

Earlier quoted context omitted.

RTK GPS is 1cm RMS. And I still can't get over how awesome it is. It's magic.

I had no idea what RTK was before your comment. Thanks! Here's a link[1] for others who might be curious. Looks like the key is being within ~6mi of a RTCM (Radio Technical Commission for Maritime) station that transmits GPS correction data. If not, the cool thing is that you can create your own station as well by daisy-chaining off of an existing station that's within 6mi. [1] https://learn.sparkfun.com/tutorials/wh…

For these purposes, you could just have a single reference receiver at the site.

That is, with two GPSes, you can measure their vector distance very precisely by correlating their measurements.

But it doesn't help you precisely measure angles, which is a big part of this problem.

Re: Heliogen, backed by Gates, says it has achieved a solar breakthrough

#64

Post by mlyle »

hirundo wrote: post #29
jws wrote: post #15

One of my discarded project ideas was exactly this, but on a smaller scale. A steerable mirror on a mount with a camera for targeting. The idea was to place one on the ground outside a north facing window. The device would then busy itself reflecting the sun up into the room making a nice sunny patch on the ceiling to light the room. They could also be used to deliver extra light to windows with plants in them to gro…

Add similar software to a swarm of drones each carrying mylar film stretched on a lightweight rigid frame with a vertical tilt actuator, and you have a seriously dangerous weapon system on sunny days.

It's hard to point what's basically a giant sail on an airborne drone.

Re: Heliogen, backed by Gates, says it has achieved a solar breakthrough

#65

Post by pbhjpbhj »

splittingTimes wrote: post #47
SiempreViernes wrote: post #27

Earlier quoted context omitted.

The motion of the Earth in space is very well determined and studied; the thermal expansion and deformation of the structure is most likely the dominant source of uncertainty for the pointing.

I am wondering if these effects are really important and warrant the use of "AI". If so, then what is the size of the target? If it is only some cm^2, then they still have a long way to go till it can handle industrial sized problems. Once you are at industrial scale, do you still need that kind of accuracy??

I don't think it's about warranting "complex AI" it's that this solution plays out as easier to apply in practice.

I think it's a scale issue, each mirror needs the same apparatus and AI, but doing it traditionally with reactive optics would need a multitude of different pieces?

Re: Heliogen, backed by Gates, says it has achieved a solar breakthrough

#66

Post by sanxiyn »

splittingTimes wrote: post #47
SiempreViernes wrote: post #27

Earlier quoted context omitted.

The motion of the Earth in space is very well determined and studied; the thermal expansion and deformation of the structure is most likely the dominant source of uncertainty for the pointing.

I am wondering if these effects are really important and warrant the use of "AI". If so, then what is the size of the target? If it is only some cm^2, then they still have a long way to go till it can handle industrial sized problems. Once you are at industrial scale, do you still need that kind of accuracy??

These effects are really important. That's why previous attempts failed.

Re: Heliogen, backed by Gates, says it has achieved a solar breakthrough

#67

Post by PhilippGille »

jws wrote: post #15

One of my discarded project ideas was exactly this, but on a smaller scale. A steerable mirror on a mount with a camera for targeting. The idea was to place one on the ground outside a north facing window. The device would then busy itself reflecting the sun up into the room making a nice sunny patch on the ceiling to light the room. They could also be used to deliver extra light to windows with plants in them to gro…

There's a Norwegian town that did something similar: During winter the mirror (mounted on a hill) reflects the sun to the town's market square, because otherwise there wouldn't be any sunlight due to the sun being too low. https://www.theguardian.com/world/2013/nov/06/rjukan-sun-nor...

Re: Heliogen, backed by Gates, says it has achieved a solar breakthrough

#69

Post by sanxiyn »

jerry292 wrote: post #46

@elonmusk please work with integrating battery tech with these guys!!

This is not an electricity production technology. The goal is heat, not electricity.

For electricity production, photovoltaics is superior to concentrated solar power.

Re: Heliogen, backed by Gates, says it has achieved a solar breakthrough

#70

Post by deepnotderp »

anonuser123456 wrote: post #36
analognoise wrote: post #19

Again, we've been able to do this with four photodiodes for something like 30 years. Of course it worked the first time they turned it on - they were using 4 photodiodes. The "AI" and "computer vision" is just to get funding and hype. I'm going to start taking solved problems and applying BS "AI" to them to get funding, sheesh.

I somehow doubt Gates gets fooled by hype. Do you think he just stumbled his way to success? Maybe there is a little more complexity to the problem than you anticipate.

Even Einstein was wrong about some things, that is no argument.

But yes, fiducial marks probably don't work well here due to too many variables.

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