Researchers make a supercapacitor from water, cement, and carbon black

And a fair chunk of that is the summer holiday season, when a lot of people won't be home anyway.

It is possible to mis-design houses and apartments to need it more than that (extreme sun traps essentially); schools/offices and public transport are a different case because of the number of human bodies in a small space.

But our homes need A/C so rarely that it's not worth it, same as most people don't have winter tyres or snow chains, or even know how to fit them. Materially significant amounts of snow for a few days one winter in three, unless you live in Scotland or the Pennines.

UK housing is mostly quite old - an average age of 50 years or so. Modern insulation requirements only became law in the last 20 years. Most houses aren't particularly well insulated - and most houses haven't had much retrofit work done. The UK is really far behind most of Northern Europe in this regard.

I think the rest of your reasons are valid. Average floor area is probably half that of a US house. Domestic air conditioning is almost unheard of. Almost everyone heats with natural gas.

Heating is a huge part of energy demand - around 25% of UK total energy goes into space heating - so if you're not doing that via electricity then average energy consumption per house will be much lower.

Electricity cost is currently running at about 28p/KWh. I presume that's a lot more than the US. Electric heating is indeed rarer because gas is about 1/3 of the cost.

I'm thinking your points about air conditioning is likely the major difference combined with the average US home being larger so more space to air-con. Few UK homes have air conditioners (offices do) as it doesn't usually get hot enough. Although this has started to change in the last few years and I'm seeing them occasionally popping up now on neighbours houses. I wouldn't have needed one this year at all so far. Last year, maybe for one week. I was thinking about it but by the time you've looked into organising something the heat has gone and you forget about it until next year. There is a push to move to heat pump heating instead of gas and those units often can do air-con as a byproduct so that may be a driver for change.

Tumble driers are easily available and definitely widespread in the UK. The lack of tumbler driers is a bizarre myth I see again and again on lists of differences between the US and UK. I have no idea how the authors of these lists come to this conclusion. The only idea I have is maybe people from the US who come to the UK rent a furnished house and the landlord cheaps out and decides not to supply one. I do have one and it runs to about 2KWh a load maybe? I don't think that would explain the difference in any case.

My 20 year old drier uses about twice amount of kwh as my 7 year old dishwasher (on actual clean mode, not "eco: everything is still dirty and you should do it by hand mode"). I also use it far less, so on average they are about the same.

I recall in my great grandparents old terrace house, the kitchen was set behind the neighbors fireplace. The only rational place for the fridge stand effectively copped 50-80 degrees from the neighbors fire, just radiating from the brick. This lead to the fridge running constantly and having an extremely short lifespan (and sometimes not functioning at all)

That said because it was old everything was air dried.

Also there was just no HVAC there to begin with, so I guess even less of an HVAC bill.

A small chunk of buildings built in the 60's use electricity because we thought that would be cheap in a post-nuclear world. We were wrong.

I would argue that the USA as a whole generally has more climate variability than the UK in addition to larger housing to account for the overall energy usage as well.

that's quite the assertion, what makes you believe it to be true?