perestroika

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.

It sure is possible.

A typical "obscenely bright" LED chip might be Cree XML, but many similar chips exist. You'd need a plano-convex or equivalent Fresnel lens - shorter focal lengths favour compact design. Then you need a driver. Some are fixed while some adjustable with a tiny potentiometer. You'd need an 18650 cell holder (it can be made too, an 18650 will go into a leftover piece of 20 mm electrical cabling pipe with a spring-loaded metal cap engineered of something).

Myself, I bought a nice head lamp, but it broke after one year. The driver board failed. Being of the lazy variety, I replaced the board with a resistor to limit current and now it's been working 3 years already. Not at peak luminosity, the resistor wasn't optimal of course. :)

I think the EU Commission has done a fairly good job of listing the pros and contras of small modular reactors:

https://energy.ec.europa.eu/topics/nuclear-energy/small-modular-reactors/small-modular-reactors-explained_en

They have some advantages over conventional (large) reactors in the following areas:

• if they are serially manufactured without design chances, manufacturing is more efficient than big unique projects
• you can choose a site with less cooling water
• you can choose a site where a fossil-burning plant used to be (grid elements for a power plant are present) but a renewable power plant may not be feasible
• some of them can be safer, due to a higher ratio of coolant per fuel, and a lower need for active cooling*

Explanation: even a shut down NPP needs cooling, but bigger ones need non-trivial amounts of energy, for example the 5700 MW plant in Zaporizhya in the middle of a war zone needs about 50 MW of power just to safely stay offline, which is why people have been fairly concerned about it. For comparison, a 300 MW micro-reactor brought to its lowest possible power level might be safe without external energy, or a minimal amount of external energy (which could be supplied by an off-the-shelf diesel generator available to every rescue department).

The overview of the Commission mentions:

SMRs have passive (inherent) safety systems, with a simpler design, a reactor core with lower core power and larger fractions of coolant. These altogether increase significantly the time allowed for operators to react in case of incidents or accidents.

I don't think they will offer economical advantages over renewable power. Some amont of SMRs might however be called for to have a long-term steerable component in the power grid.

Wow, that's a nice one. :)

Also, both of your links to solar-powered tool projects were educational. I knew this could be done, but I had never read about peope doing that. :)

I noticed a journalist mention (hopefully based on good sources) that this months's storm was estimated to be 4-5 times weaker than the 1859 storm.

NASA, in their article mentions the recent storm as a G5 level geomagnetic storm caused by an X8.7 level solar flare.

X is the strongest class of solar flares and G is the strongest class of geomagnetic storms, but this was definitely not a record - an X20 flare has been observed once, but as I understand, the ejected particles didn't hit Earth.

Where I live (latitude 59), a short electrical grid event occurred during the display of auroras. Something tripped and something immediately switched over to replace it, most people didn't notice anything, but some had to restart various heat pumps and similar devices. Then again, in Europe, the power grid has relatively short lines and many transformers between them, which makes it comparatively less vulnerable.

Regarding transformers: it's easier to let a power grid trip offline (and transformers are designed to behave so instead of being overpowered) rather than to keep operating despite a Carrington level solar storm and suffer failure on all longer east-west connections.

Also, I don't think they used capacitors to protect their high voltage lines back in 1921, because the article Overvoltage Protection of Series Capacitor Banks notes:

"Their first application dates back to 1928 when GE installed such a bank – rated 1.2 MVar – at the Ballston Spa Substation on the 33 kV grid of New York Power and Light. Since then, series capacitor banks have been installed on systems across the globe."

Also, failure on north-south connections isn't nearly as likely, so a considerable part of the transformer "population" would be spared from impact.

Thus, while a single strong solar storm within the limit charted out in 1859 would be an extreme inconvenience and strong economic setback, it seems unlikely to end civilization.

A long period of severe solar storms could also result in ozone depletion in the atmosphere and become another extreme inconvenience - through increased UV exposure. However, most forms of life have seen such things in their evolutionary past, and humans have the ability to wear glasses, clothes and apply sun screen.