On individual scale, precisely that - a split type AC with one half indoors (or in a water tank) and the other half in an outdoor environement (air, water or ground).

If you’re extracting heat from the environment, the machine lets the working fluid evaporate into the outdoor heat exchanger and compresses it back into the indoor heat exchanger. If you’re cooling your premises - reverse that.

However, on a city scale, it’s like “you’ve got a lot of sewage at 30 C” -> “your heat pump is a large building” -> “your sewage outflow is now at 10 C, but your underground heat reservoir gets charged to 140 C (stays liquid because of water column pressure), and you spend much less energy pumping the heat than you would spend heating the water directly”.

Relays: my use for truck relays is switching on heaters in my thermal storage water tank. Not big ones, though - I use relays rated for 24V and 40A of current. Since they are old, I have applied a safety margin and only let 25 A flow through them, so each of them handles 24 x 25 = 600 W.

As for using DC appliances: benefits do exist. If a household has a low voltage DC battery bank (some do, some don’t) then dropping the battery voltage a few times to power car parts comes with a smaller efficiency loss. In my household, DC appliances are used for lighting, communications, computing, cooling food, pumping water and soldering electronics. The rest goes via AC. I think a car air conditioner could cool some small storage room decently. With big living rooms, it would have difficulty since it’s a small device.

Relays can be used for anything, and a car contains a fair number.

You can make a pulse jet engine from a muffler parts, but a solarpunk society would probably not do that. :)

Copper brake pipe and cooling radiators can be used as heat exchangers for other stuff.

Air conditioner parts can be reverse-used for Stirling engines or to pump heat in other contexts.

As an anarchist who would welcome other anarchists - sadly, I doubt if that’s a reliable recipe to stop climate change.

Limiting (hopefully stopping) climate change can be done under almost any political system… except perhaps dictatorial petro-states. However, it takes years of work to tranform the economy. Transport, heating, food production - many things must change. Perhaps the simplest individual choices are:

• going vegetarian (vegan if one knows enough to do the trick)
• avoidance of using fossil fueled personal vehicles
• improving home energy efficiency (especially in terms of heating)
• avoidance of air travel
• avoidance of heavy goods delivered from distant lands

The rest - creating infrastructure to produce energy cleanly and store sufficient quantities - are typically societal choices.

As for corals - I would start by preserving their biodiversity, sampling the genes of all coral and coral-related species and growing many of them in human-made habitats. If we’re about to cause their extinction, it’s our obligation to provide them life support until the environment has been fixed.

Also, I would consider genetically engineering corals to tolerate higher temperatures. Since I understand that this is their critical weakness, providing a solution could save ecosystems. If a solution is feasible, that is.

Corals reproduce sexually so a useful gene obtained from who knows where would spread among them (but slowly - because typical colonies grow bigger asexually). Also, I would keep in mind that this could have side effects.

As for tempeature - it will be rising for some time before things can be stopped. Short of geoengineering, nothing to be done but reduce emissions, adapt, and help others adapt. The predictable outcome - it will get worse for a long while before it starts getting any better.

News of the sentencing reached the public broadcaster here in Estonia, including Dale Vince’s comment that “this resembles Russia or maybe North Korea” and Chris Packham’s assessment that “this is a threat against freedom of speech”.

I hope the judgement gets overturned on appeal, and the law that enabled the judgement gets scrapped or rewritten.

I also suspect that the next people who want to stop traffic will not choose peaceful assembly as their method, but will use far more dangerous methods - sabotage from distance, e.g. no more traffic lights on a big intersection. Needless to say, state will cry “terrorism” then, and that is not a desirable outcome, so I hope nobody feels compelled to prove the point.

The Ugandan military playing security guards for a China-controlled oil project… I think explaining human rights over there will have to start from zero - and may have to be backed with “or else” statements - if there exists an institution in a suitable position to issue them. :o

I would add:

• if you wanted direct and low-latency access to cameras (for machine vision)

1 C more temperature -> air can hold 7% more water vapour

…but the peaks of fringe events are quite a bit taller than +1 C. Raising the average by 1 C raises the peaks considerably more.

Summary:

But then, in the geologically abrupt space of only a few decades, this great river of ice all but halted. In the two centuries since, it has moved less than 35 feet a year. According to the leading theory, the layer of water underneath it thinned, perhaps by draining into the underside of another glacier. Having lost its lubrication, the glacier slowed down and sank toward the bedrock below.

/…/

“The beauty of this idea is that you can start small,” Tulaczyk told me. “You can pick a puny glacier somewhere that doesn’t matter to global sea level.” This summer, Martin Truffer, a glaciologist at the University of Alaska at Fairbanks, will travel to the Juneau Icefield in Alaska to look for a small slab of ice that could be used in a pilot test. If it stops moving, Tulaczyk told me he wants to try to secure permission from Greenland’s Inuit political leaders to drain a larger glacier; he has his eye on one at the country’s northeastern edge, which discharges five gigatons of ice into the Arctic Ocean every year. Only if that worked would he move on to pilots in Antarctica.

It’s not wild at all. :) The plan makes sense from a physical perspective, but should not be implemented lightly because:

• it’s extremely hard work and extremely expensive to drain water from beneath an extremely large glacier
• it doesn’t stop warming, it just puts a brake on ice loss / sea level rise

If the motor mount is hackable with reasonable effort, and the motor controller’s interfaces are open, then in principle… yes.

Yet in reality, companies build extremely complicated cars where premature failure of multiple components can successfully sabotage the whole. :(

I’ve once needed to repair a Mitsubishi EV motor controller. It took 2 days to dismantle. Schematics were far beyond my skill of reading electronics, and I build model planes as an everyday hobby, so I’ve seen electronics. Replacement of the high voltage comparator was impossible as nobody was selling it separately. The repair shop wanted to replace the entire motor controller (5000 €). Some guy from Sweden had figured out a fix: a 50 cent resistor. But installing it and putting things back was not fun at all. It wasn’t designed to be repaired.

Needless to say, replacing a headlight bulb on the same car requires removing the front plastic cover, starting from the wheel wells, undoing six bolts, taking out the front lantern, and then you can replace the bulb. I curse them. :P

But it drives. Hopefully long enough so I can get my own car built from scratch.

Thanks for the news, but also - thanks for posting a proper summary. :)

(So many videos have only the YouTube-compiled summary, which is typically totally off topic.)

Interestingly, warfare also has the effect of:

• causing houses to be abandoned, necessitating houses elsewhere while the abandoned ones likely get bombed

• decreasing the number of future consumers, whose future footprint would depend on future behaviour patterns (hard to predict)

• changing future land use patterns, either due to unexploded ordnance or straight out chemical contamination (there are places in France that are still off limits to economic activity, because World War I contaminated the soil with toxic chemicals), here in Estonia there are still forests from which you don’t want trees in your sawmill because they contain shrapnel and bullets from World War II

I have the feeling that calculating the climate impact of actual war is a difficult job.

But they could calculate the tonnage of spent fuel and energy, that would be easier.

Nice to hear. :) The process seems doable in a suitably equipped factory. :)

Well, a heat wave cannot last forever. And in terms of cold storage - it’s +30 C over here currently already for a week, it has been 1.5 months since the last snowfall - and the last pile of snow on the local airport is still melting. Darkened, not recognizable as the substance it used to be, but existing, without people making the slightest effort to protect it. :)

what the hell are we going to do?

In the very long term, stop climate change.

In the long term - dig in and design heat shelters, most likely. Because it’s cooler underground and heat waves will pass. When a bad one comes, people would stop working and find shelter from it. One can even accumulate cold in a thermal store during cool periods and distribute the cooling effect to premises during heat waves.

In the short term - those who can (there will be an equality and access problem) and those who must (who cannot stop working) would install air conditioners and similar stuff.

I don’t even want to imagine 50 C. In sauna, it’s dry and you manage 30 minutes by sweating. But living in a sauna sounds bloody awful.

Also, almost anyone with a med / bio background will say - emergency rooms will be full at 50 C, and morgues will be crowded a few days after the event. :(

The transfer to electricity could be done by using the heated mass to heat a hot pumped liquid or using transfer rods made of a solid material with a high heat transfer coefficient.

Alternatively, heat can be extracted by pumping liquid metal (sodium, tin, low-temperature eutectic alloys) in a pipework of copper (if there is chemical compatibility with copper). But handling liquid metal with a magnetic pump isn’t typically done on the DIY tech level.

To be honest, I tried a fair number of experiments on the subject, including low-temperature Stirling motors. They’re difficult to build well. I would recommend plain old steam turbine. Steam means pressure, pressure means precautions (risk of bursting, risk of getting burned), but modern approaches to boilers try to minimize the amount of water in the system, so it couldn’t flash to steam and explode.

I have superficially researched both options (with the conclusion that I cannot use either, since my installation would be too small, and would suffer from severe heat loss due to an unfavourable volume-to-surface ratio - it makes sense to design thermal stores for a city or neighbourhood, not a household).

I’d add a few notes:

1. A thermal store using silicate sand is not limited by the melting point of the sand, but the structural strength of the materials holding the sand. You can count on stainless steel up to approximately 600 C, more if you design with reserve strength and good understanding of thermal expansion/contraction. Definitely don’t count on anything above 1000 C or forget the word “cheap”. I have read about some folks designing a super-hot thermal store, but they plan to heat graphite (self-supporting solid material) in an inert gas environment.

2. Heat loss intensifies with higher temperatures, and the primary type of heat loss becomes radiative loss. Basically, stuff starts glowing. For example, the thermal conductivity of stone wool can be 0.04 W / mK at 10 C, and 0.18 W / mK at 600 C.

3. Water can be kept liquid beyond 100 C. The most recent thermal stores in Finland are about 100 meters below surface, where the pressure of the liquid column allows heating water to 140 C.

4. However, any plan of co-generation (making some electricity while extracting the stored heat) requires solid materials and high temperatures.

True, but toppling over can leave them intact. One of my foolish neigbours didn’t anchor his panel carriers properly and thought a thick fir hedge would protect them enough. A storm from unexpected direction threw four panel carriers (9 panels each) face down and severed the cables, so everything had to be disconnected and there was a safety risk (but not during night). I helped with the recovery work and not a single panel was broken.

…and that is why I no longer mount any solar panels horizontally. Not a chance in hell of withstanding that, and one of such storms hit within 150 kilometers last year. Within 30 years, I bet I’ll experience this effect.

Meanwhile, vertical panels can be up-armored (e.g. wooden beam running on top) to withstand such events.