[trashtester]

The battery capacity needed to replace all cars with electric ones is about two orders of magnitude lower than the battery capacity needed to replace all fossil fuels with wind and solar, at least in temperate regions, where you need heating during the winter.

According to this MIT study, the cost (LCOE) of doing this today, would be $3000/MWH:

https://www.greencarcongress.com/2021/08/20210829-mitei.html

Even if the cost of batteries continue to come down by x4 in price every decade from now on, it will take 30-40 years for prices to come below current energy prices.

If we hit an S-curve before then, it could take much longer.

[7952]

I was arguing that we shouldn't put all our eggs in one basket and the scale of the challenge really confirms that. But yes, I do think that the battery industry has the best chance of scaling up and achieving order of magnitude improvements. But we don't actually need that for that industry to play a part in defeating climate change. And failure to meet some hypothetical objective does not invalidate that. Again, we don't need to put all our eggs in once basket and that certainly means not relying 100% on battery storage.

[fulafel]

That link is summarizing a nonpublic paper from a research group making the case for hydrogen as grid storage for California, not a very strong cite for this.

Generally keeping houses warm with low evergy is solved, well insulated passive houses need little heating energy even in places with long cold winters.

[trashtester]

That link links to MIT's summary, which in turn links to this original paper:

https://www.sciencedirect.com/science/article/abs/pii/S03062...

(probably paywalled)

> Generally keeping houses warm with low evergy is solved, well insulated passive houses need little heating energy even in places with long cold winters.

What is your definition of "places with long cold winters" and how much energy do you think it takes (kwh) to heat a house in such climates during winter?

[fulafel]

Have a look in eg p.43-46, 75, 117, 143 in https://portal.research.lu.se/en/publications/passive-houses... for one case of building standards back in 2009. There isn't really a energy efficiency limit there being approached, just a matter of what had been picked as a cost efficient target, so there are no absolutes. I'm betting current designs are more efficient, as that has been a constant trend, but don't have newer references on hand.

In practice it seems going much lower than half as much as hot water uses may be wasteful investment as long as water is not heated with local renewables.

[trashtester]

The savings depend on what you benchmark against. But energy savings between 50-75% for a new house compared to an old one, seems realistic. And maybe older houses could be modernized in ways that would save 25%-50% in many cases.

Tearing down all old houses and building new ones is obviously not an alternative, so a transition to new standards is likely to take 50 years or more, even though some of the benefit can be realized by modernizing existing housing.

But even $30000-€50000 euros to lower energy consumption is also a big investment for many families, and even WITH that investment, heating prices in Norway and Sweden will be 2-3x historic prices if prices stabilize at current levels, especially if the governments stop subsidies.

I think every country will have trouble bringing their population to accept having to use electricity at prices about €0.1/kwh, even if over a very long term, it is possible to build houses (at extra costs) that bring the consumption down a bit. At such prices, people in Germany, Denmark, Poland, Hungary etc will simply continue burning natural gas indefinitely.