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

Post by kjeetgill » Sat, Jan 04, 2020, 10:34 PM UTC

sansnomme wrote: post #17

amelius wrote: post #11

Earlier quoted context omitted.

Can't you then solve this by having a bunch of photodiodes under the edge of each panel, indicating if the panel is placed correctly?

Ssh, hacker news hates simple solutions like fiducial markers. I wonder if HN would dare to ride a spaceship that uses neural network to perform docking alignment.

Post by bullen » Sat, Jan 04, 2020, 10:48 PM UTC

jws wrote: post #35

bullen wrote: post #21

Cement requires 1450 degrees Celsius, this solar raid manages 1000+!? how are you going to boil heavy lime and clay up on that 10 meter high tower? Everything Bill Gates has ever done (or financed) has been stolen, a fraud or both. Edit: Whoa, heavy bias towards Mr Gates, a surprise dear HN community. I'm using my karma to learn! ;)

A reply into oblivion… but generally you would circulate molten sodium through the system to transfer heat to ground level where you do work and have storage tanks for hot sodium when the sun isn’t shining.

Post by cjsawyer » Sat, Jan 04, 2020, 11:11 PM UTC

pbhjpbhj wrote: post #61

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?

Post by core-questions » Sun, Jan 05, 2020, 12:26 AM UTC

lifelongUU wrote: post #87

core-questions wrote: post #86

Earlier quoted context omitted.

Could you expand on what closed/open loop mean in this context?

Open loop means that they’re just using a mathematical prediction of where to point the mirror at a specific time, given the relative position between the heliostat, the target and the sun. adjustments to the mirrors are typically done every 10 to 15 seconds, which is sub optimal. Closed loop means that they’re actually using Computer vision to dynamically sense the specific angles between the sun and the target and…

Post by mlyle » Sun, Jan 05, 2020, 12:41 AM UTC

core-questions wrote: post #97

mlyle wrote: post #90

Earlier quoted context omitted.

Yah, it's a slight misnomer because both loops are likely closed. Open/closed loop basically means whether you check the result of an actuation. What we're really talking about is the point at which the loop is closed. A completely open loop would run the motor for the predicted time. A simple closed loop would run the motor until the mirror is pointing at the predicted angle, using an encoder to know where the mirro…

Makes sense. So closed loop basically means there's a feedback mechanism in place to ensure that the input results in the desired output, or some sufficient proxy thereof.