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”.

I have had many encounters with cops, and I decide about the extent of cooperating with them on a case-by-case basis.

• landlord is illegally evicting my mother’s neighbour --> I call cops and they prove how useless they are at prevention, but the matter goes to court and the landlord gets convicted later, and it was my only time to testify in court
• cops accuse me of ignoring their lawful order --> sorry, I was listening to music, didn’t hear nothing, no comment, no comment, I admit nothing (nothing came of it)
• cops intrude into the squat yard without knowing it’s a squat --> “the droids drunken people you look for are elsewhere” --> the cops go elsewhere
• cops raid the squat --> refuse to provide documents until threatened, require cops to provide their own ID, contest every statement and discuss the matter publicly in media
• cops try to steal equipment during a demonstration --> pull the equipment back and yell to them a description of what it is (I assume they thought I was planting a bomb instead of packing up)
• cops want to interview me about illegal demonstrations --> I politely tell them to fuck off, then call back and volunteer for the interview to convey the opinion of other anarchists :D
• a new squat is being established --> establish a security perimeter that is watched with attention and never let cops close
• an attempted squat gets burglarized and set on fire -> inform the fire brigade that a bottle of propane could be present (fortunately it was stolen), the fire brigade had better things to do than involve cops
• a new squat gets burglarized --> pepper spray the burglar and take their tools, without involving cops
• a new squat gets burglarized, episode N --> threaten the burglars and take their tools, without involving cops
• cops try to fall into a hole in ground during a stupid training excercise --> tell the cops not to go there, as they might fall in (leave untold: it would be a major embarrasment for squatters to rescue them)
• the squat is suddenly in the security perimeter of a NATO summit --> find some military lurking in the yard and invite them into the squat so they could be reasonably certain we don’t have anything that shoots down planes :P (runway was about 250 m away)
• a drunken person tries to SWAT me at a street party --> fully explain the situation to the SWAT team and later participate in amateur theatre with cops to get the drunken person safely removed from the police station :o
• one drunken neighbour hits their spouse and when I forbid, hits me --> seeing that the neigbour has already paid for his deed since pepper was 100% effective and he’ll feel extremely bad for many hours, I did not file a complaint to cops, although they were called and showed up
• after two geniuses tried to steal my car, but fled after a warning shot --> I did not involve cops
• after some person attacked his partner and hit her on street --> I pepper sprayed him, and since he took out a knife and attempted to come at me (I evaded, no harm occurred to me), I did call cops and make a complaint, as did the woman he had hit
• cops call me about one neigbour’s car --> I don’t remember anything (I did actually remember, but wasn’t in a mood for helping them repress a neighbour)
• my car gets burglarized --> I ask the cops for info, they have none, I don’t involve them beyond that

…etc.

P.S. I have once used DC to power a pump “directly”. I use quotation marks because the pump (a water pump) was a brushless DC motor with an integrated controller. I used it on a field for removing water after a spring flood. Its controller accepted 24…48 V input, and it was powered from a 40 V solar panel brought on a wheelbarrow. :)

instead of powering the heat pump from the wall, the heat pump can be connected directly to a PV

I have no experience with this exact combination. I know that “batteryless” inverters exist, but most of them are on-grid inverters. In that scenario, all that matters is monitoring your production: if you don’t want grid energy, you only run your system when your PV produces enough.

Another type of batteryless inverters are “pump inverters”. Farmers seem to like them for pumping water from wells into water towers. A pump inverter can be configured to run at 50 Hz (or 60 Hz for North Americans) and 230…240 V (or 110 V for North Americans) alright, but it is not designed to power electronic devices, but dumb agricultural motors. There is considerable risk involved with powering a heat pump from a pump inverter, unless you find an exceptionally simple and dumb heat pump with very limited or resilient steering electronics.

Efficiency losses are small anyway, but mostly happen during battery storage or when voltage needs to rise or drop considerably (e.g. a transition of 700 -> 24 V or 24 -> 240 V would cause a small efficiency loss).

I’ve heard that a PV can directly power a compressor

This seems unlikely as the compressor would have to be a brushed DC motor. That kind of motors don’t last long, they wear out their brushes. Long-lasting motors are brushless, and those generally cannot be run on DC power. For example, a “brushless DC” motor is essentially a three-phased AC motor, just its controller (full of smartness and MOSFET transistors) accepts DC input.

If you have a good technical overview of your heat pump system, maybe you can locate a point where regulated DC can be fed into the system, but that would be hacking. Alternatively, maybe a niche market already exists for DC-powered heat pumps, e.g. for caravans, trucks or ships? But on niche markets, prices typically aren’t good for you. :(

Mulje: arutelu oli huvitav, kuid aega oli selleks liiga vähe. Kohal oli mitukümmend inimest, kellest osad kirjutavad ministeeriumile enne kooskõlastusringi tähtaja lõppu.

Kohal oli siseminister Läänemetsa nõunik, kes veidi ümarat juttu ajas, kuid ilmselt ka kõrvad lahti hoidis.

Eks vaatame, mida sealt tuleb. Kui tuleb mingi halva maiguga eelnõu, siis peab lipud ja loosungid kolikambrist välja otsima.

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.

it would (as far as i understand with high school chemistry) be strictly more efficient to electrolyse rust directly

I’m not a chemist either, but I do know a bit of chemistry.

Typically, you need a solution of NaOH (sodium hydroxide) to directly reduce iron oxide in an electrolysis cell. If your iron oxide contains impurities, those may react with NaOH and ruin the fun. Also, if you have exposure to CO2, your NaOH will gradually degrade, producing NaHCO3 and losing potency.

My impression: wet electrolysis is great for making high purity iron, but it would be hard to make it work for energy storage.

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.

Wow, really interesting tools. :)

But sadly not for me - I left biology behind at some point and have fallen off the sleigh so badly that I’d probably need a year of study before I could use this tool for something less than practical (e.g. make a bacterium glow in the dark).

As a rule of the thumb, the longer your stomach (and its bacteria) have to work to get calories extracted from a food (this has a big correlation with the food not being excessively pre-processed, and also has a big correlation with lack of additives) - the better it is for you. :)

We will surely learn the precise reasons later. Until then, acting upon that information is possible without knowing why. :)

Well, today they are actually in production, while 5 years ago they were in laboratories.

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.

The interesting part: Democrat officials made public statements about going silent for a while, and those statements reached headlines even in Europe. You can go silent and still have your statements in headlines.

Also, as far as money and efficiency are involved - if they save money now, they can advertise more later. Currently, advertising against Trump would have a low efficiency, since he currently receives positive attention. I think their current action plan is “let’s wait for Trump to open his mouth”.

Knowing psychology, almost any PR advisor will advise to temporarily cease media attacks against a person who’s been shot.

As a minimum, messages may need to be reworded, because Trump is likely to change his messaging after his narrow escape.

Some notes:

• almost no doubt: this will have a mobilizing effect for Trump supporters (“our great leader is being attacked”, etc)

• possibly: this will improve Trump’s ratings among voters with no clear political preference (a big story where he’s not the villain is what he needs)

• pattern: historically, surviving an assassination attempt has improved a candidate’s chances of getting elected; in the most recent example, Slovakia’s prime minister Fico enjoyed a boost in ratings while in hospital after being seriously wounded

I don’t blame Democrats for temporarily ceasing campaign advertisement. Two principles dictate this: “you don’t kick a person who is already down” (Trump was incredibly lucky and isn’t) and “you don’t attack someone who has martyrdom effect”. Generally, you wait until the dust settles. Democrats too will wait until the dust settles. They will also check the popularity ratings and decide how to proceed.

In my opinion, Democrats would strongly benefit from a younger candidate. I would advise getting someone under 55 to run. Among the wider population, not enough people understand that, as things are, the Democratic candidate is Kamala Harris, her name is just currently Joe Biden. :o

Overall, it seems that Trump has considerable chances of getting elected president. Preventing that will require exceptional effort and considerable luck. Only if the Democrats manage to paint a clear picture of what a Trump presidential term would bring about, and only if that picture causes their voters to show up and vote nearly without exception - only then will things turn out differently.

My personal view from Eastern Europe - contingency plans for a Trump presidency ceasing aid to Ukraine have a very high probability of occurrence now (estimated time: early 2025). Over here, everyone and their cat will researching cheap weapons systems to replace things that only the US can provide. I think that group will now include myself.

Nice to have it here, but due to the practical nature of the demonstration, I think this video could have flown better on c/technology or c/diy - or something of that sort. :)

But yep, moving heat is a lot smarter than creating it. :)

Nice and thorough overview. :)

The article is mostly correct. :)

Notes: out of the three, Latvia has serious energy storage - a 4 billion cubic meter (at normal pressure) underground gas store, sufficient to carry all three countries over the winter. So far, it’s filled with fossil natural gas - but some day it could be filled with synthesized methane.

As a backup option, Estonia has oil shale - probably the worst fuel on Earth, so the price of emitting CO2 keeps those plants out of the energy market during summer. During winter, they come online though.

As for solar, we aren’t planning to rely much on that. Solar capacity has of course skyrocketed, but only because it’s very easy to install. For me, it provices a nice way to charge my car from April to October. But at latitudes 55 to 60, days are really very short in midwinter, so wind and waste wood are the likely candidates in future - after oil shale leaves the scene, but before synthetic gas becomes feasible.

Regarding pumped hydro - it can stabilize a day, but can’t stabilize a week or month. Lithuania has a biggish (~10 GWh) pumped storage facility. The rest of Baltics don’t have suitable terrain. Estonia has limestone banks, but they’re under various forms of protection and even if one built a lot of pumped hydro, the low elevation difference (up to 50 meters) means one couldn’t support the electric grid through more than a few days.

Regarding hydrogen - maybe. But hydrogen is difficult to store, so I’m betting on wind, and on sourcing technology from Germany to produce synthetic methane from excess power during summer, and pumping it to Latvia for storage.

Finally - connecting to the continental EU power grid allows importing energy when local wind isn’t strong enough, and exporting any surplus. So far, all three countries are still in the ex-Soviet synchronization area (common with Russia and Belarus, but with no trade, just synchronization), and thus unable to connect with the EU synchronization area. Local power companies have been building synchronous compensators (devices that steer grid frequency) for the past 2 years to drop this dependency.

If things go as planned, Baltic countries will sever those connections and join the EU grid via Poland in winter 2025. Undersea cables already go from Estonia to Finland and Lithuania to Sweden, but in the current political conditions, I don’t think anyone counts of them for sure (a Chinese-owned but Russian-crewed ship broke the Estonia-Finland gas pipeline last autumn when dragging its anchor during a storm - it’s still unsure if the damage was accidental or not).

But that’s not what we found. In fact, experimental manipulations that reduced support for the protesters had no impact on support for the demands of those protesters.

We’ve replicated this finding across a range of different types of nonviolent protest, including protests about racial justice, abortion rights and climate change, and across British, American and Polish participants (this work is being prepared for publication). When members of the public say, “I agree with your cause, I just don’t like your methods,” we should take them at their word.

Wow, that is both new (at least for me) and interesting - thanks for sharing this article. :)

I note a potential weakness in the method of analysis: if negative framing (e.g. by the media) reduces support for the protesters as persons (but not their cause), it may still somewhat harm their ability to bring about change, since it probably reduces people’s willingness to team up with them - but not another group which has the same cause but different methods.

So, if the goal is mass action (which has a component of mobilizing like-minded people to join) I would strongly recommend a protester to choose non-controversial methods (so that even grannies can join). :)

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