Heliogen, a clean energy company that emerged from stealth mode on Tuesday, said it has discovered a way to use artificial intelligence and a field of mirrors to reflect so much sunlight that it generates extreme heat above 1,000 degrees Celsius.
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The article describes a bit about the role the AI is playing, and Heliogen didn't seem to me to have used "AI" as a buzzword
Animats gave a nice summary [1] of the Vox article [2] that went into some detail. [1] https://news.ycombinator.com/item?id=21580596 [2] https://www.vox.com/science-and-health/2019/11/19/20970252/c...
In principle I think you are right, but that would mean for each plant you build you need the exact position of each mirror, the oven chamber and the motion of the sun through the day and year. I think the "AI" approach scales better, as it is rather simple "AI" application.
If every mirror has drifted a small angle, and you're trying to point them all at a very small target-- it's hard.
[1] https://learn.sparkfun.com/tutorials/what-is-gps-rtk/all
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.
That's just my reading of it, not asserting anything myself.
Yeah, depending on the level of precision required, there are _tons_ of variables that could have an impact here. Year to year the angle of the sun changes slightly on any given solar date, as various components of the Earth's orbit "wobble" (axial tilt, eccentricity, precession, etc). Even on an hour by hour basis, thermal expansion could have a significant impact. Any significant structure is going to settle to some extent over time, etc...
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?
But also the position of the sun in the sky is not predictable enough to do this completely open loop because of variances in atmospheric refraction... but it's pretty easily measured at the site.
I'm just going by the HelioMax blurb, where it talks about the calibration time. It makes sense that a system that automatically achieved accurate mirror aiming would also be able to maintain higher temperatures across varying conditions (and recover from disturbances and so on).
To solve the geometry problem, you need to know the inputs, i.e. position of the sun, mirror, and the target. Obvious way is calibrating in advance but that’s not reliable enough, due to wind and thermal expansion acting on the target (it’s elevated) and seismic activity acting on the ground. Another thing, need accurate orientation sensors in the mirror and/or motors capable of precise absolute positioning. All these technical challenges are solvable, but they reduce reliability, reduce focus precision especially over time, add non-trivial costs to the installation.
Instead, apparently they have 4 fixed mounted cameras around the target, looking downwards at the center of the mirror array. The sky doesn’t have distinct features unless clouds, but the sky has these color gradients, vertical one from horizon to zenith, also radial one around the sun. Just seeing these 4 colors might be sufficient to correctly orient the mirror.
Could probably find enough information here [0] what is needed.
[0] Practical Astronomy with your Calculator https://www.amazon.com/dp/0521356997/ref=cm_sw_r_cp_api_i_-v...
Also, once the AI is written, you can save time on each install by not having to precisely locate each mirror. Get it close enough, and let the magic box fix up the small errors in real time.
> The problem is that in the past concentrated solar couldn't get temperatures hot enough to make cement and steel.
> While other concentrated solar companies attacked this temperature problem by adding steel to make the technology stiffer and sturdier, Heliogen and its team of scientists and engineers turned to artificial intelligence.
> Heliogen said it is generating so much heat that its technology could eventually be used to create clean hydrogen at scale.