Absorption refrigerators are really interesting. It seems counterintuitive that you can use a heat source to drive a cooling cycle, but there are many examples. Caravans and motorhomes often have propane-powered fridges. A small flame drives an evaporation-absorption cycle that removes heat from the interior - see Einstein-Szilárd fridge patent for an example.
Perhaps not a new idea, (I have looked and found people talking about building one) but Ive not seen one working - Im sure youll all put me right in no time!
A solar collector focuses heat onto a regenerator, driving a (for instance) low-pressure ammonia refrigeration cycle.
No pumps, electronics, moving parts.
Low tech, cheap working fluids, ideal for remote, sunny locations - perhaps temperature-sensitive medical supplies in remote places.
Im vaguely hoping to build a prototype and produce free build plans for developing nation uses - Apropriate Technology.-- Frankx, Oct 15 2019 Yes, it's Baked. But because of the energy source, it only works effectively for half the day - unless you have something like a molten salt reservoir.
That means bulk and cost, to deliver functionality that can be better achieved with a battery, a photovoltaic collector, and a compressor heatpump - which is much more energy-efficient for the same cooling transfer.-- 8th of 7, Oct 15 2019 //Appropriate Technology// You need to talk to the Chinese - they've been appropriating technology for a couple of decades now.-- MaxwellBuchanan, Oct 15 2019 [MaxwellBuchanan] I read an article a while ago that suggested that, because of the rampant "reverse engineering" and blatant copying of others' designs, Chinese engineers aren't actually taught how to innovate; and as such, they don't know how to come up with their own original ideas. (It is probably a load of rubbish, but it makes a good story...) (On that note, I wonder if the Great Firewall of China lets the halfbakery through?)-- neutrinos_shadow, Oct 15 2019 Not now it doesn't.-- MaxwellBuchanan, Oct 15 2019 Hmm. How do you say "Sorry, won't happen again!" in Mandarin?-- neutrinos_shadow, Oct 15 2019 So, we should simply place all of our technological breakthroughs on website servers laced with pro- democracy / Falun Gong / Tibet / Uyghur / Hong Kong freedom movement /Tienanmen Square propaganda...-- RayfordSteele, Oct 16 2019 random, halfbakery