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Comment by throwaway9870 | Hacker News Reader

You just don't "use" heat to make electricity. You need some sort of heat engine running a cycle. All those require temperature differential. This is basic thermodynamics and isn't going to change with new technology. This temp differential is what is required to extract useful energy. So I don't understand why they talk about material at a certain temp having energy compared to oil. If we lived on a planet that is uniformly 1000 deg F, it wouldn't help us because we don't have a temp differential to convert thermal energy to electric.

Nowhere in the article did I see them mention temp differential and where they are going to dump the waste heat? Nuclear plants get crapped on because they dump heat into adjacent water bodies, how is this different?

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Ok, with the sheer amount of red flags on the article, you chose that hill to die on?

If you can get it anywhere, you go get it near the sea, and dump your heat there.

Heat exchangers running in ocean water are very difficult because they build up algae and other debris that can significantly reduce their efficiency.

None of this is rocket science, it is all well known to anyone who actually wants to do some research. Unfortunately, it seems like the people most vocal about energy are generally the least informed.

Putting the heat exchanger on a tethered weather balloon and floating it into low earth order addresses all those concerns.

It also doesn't involve rocket science.

QED.

I think you just proved my point better than I could have ever done: Those most vocal about energy are generally the least informed.

Let me guess, you have no formal engineering training, do you?

EDIT: to make this comment more constructive, here is a link to an excellent book on energy processes: https://www.amazon.com/Fundamentals-Renewable-Energy-Process...

I took a class with da Rosa and at the time this book was still in draft form, but nonetheless, excellent and easy to read. There appear to be new editions, don't know the differences.

I was being sarcastic.

However, my previous comment is technically correct. You still haven't raised any valid technical concerns with my solution.

If Mike Hughes (1) were still alive, I'm sure he'd be willing to be hired to prove me correct.

(1) The steam powered rocket guy that coincidentally became a flat earther after running out of money. The flat earthers ended up funding his (mostly) successful steam rocket.

Everyone knows the footage from NASA and the rest of the aerospace-round-earth-industrial-military-complex is all faked. Helium and Hydrogen are the devil's gas, so weather balloons also won't work.

I hope the flat earthers find some other mad scientist to replace him soon.

(Edit: I enjoyed the textbook "energy", but I've forgotten the author's name. Sadly, it's not really findable with search engines. It took a whole systems approach (including raw material extraction and maintenance)

Your point is well made. If all it took was heat, then climate change would probably be the best thing ever. More heat captured from the sun would give us more energy.

Open challenge: Getting an elected US politician to seriously propose a space heat sink as a solution to climate change.

There were some people seriously proposing big convection tubes that'd bootstrap columns of hot air, then passively pull surface air into the upper atmosphere. I can't find a link, but those wouldn't get to low earth orbit, so not a "space" technology.

I've heard of launching some large mirrors into orbit, or a bunch of small mirrors that can link together in orbit. Then you use them to reflect some sunlight off into space. I have no idea how practical this is. The bigger concern would be if something goes wrong, you need to make the mirrors deorbit quickly.

You could set it so that some of the mirrors formed a parabolic collector and heated a molten salt column, etc on the surface.

That'd have the same net effect as the giant heat sink (energy production from a heat engine, net negative flow of energy to the surface).

Wasn't there a city builder that'd let you build such a thing, where it would sometimes lose calibration and burn a swath of the city to the ground?

Futurama had a similar joke (with a reflecting mirror, not a heat collector) https://gfycat.com/hatefulvariablekakapo

Sim City 2000 I think. Yeah, getting it back here is not great. And would defeat the purpose of lowering amount of solar radiation...

>You need some sort of heat engine running a cycle. All those require temperature differential.

I lived a long time before I figured this out. It is important

I believe this is also the Achilles heel of nuclear too. It's an amazing, cheap, and sustainable way of creating concentrated heat, but an absolute pill of complexity and labor needed to turn that heat into spinning turbines. Nuclear's future should be in town heat & high temperature industry, not electricity.

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