@fribbledom I would say that by 2050 is already unfeasible, just because of the heating. It is not possible to rebuild all houses to provide better insulation in just 30 years. Perhaps in 2150…
@roobre @fribbledom I think the European plan is to refit homes to do it with that aggressive time scale. Because the alternative is worse. Northern Europe already has the issue that even well insulated homes don't benefit from more efficient appliances inside them (every Watt your TV doesn't "waste" into heat means the central heating need to spend an extra Watt to maintain warm indoor temperatures for most of the year).
@roobre I would suggest that if we're at 2050 and still using natural gas, it is already game over. Maybe we repurpose the pipelines for Hydrogen or some other system but certainly unlikely to do so undercutting price of the distributed modern electricity grid that needs to be built.
Today: absolutely true on price (where mains gas exists) but it still is only fundamentally moving where the Watt comes from not "saving" it. For future-looking, cost question vanishes.
@Asimech My point is very much from the Northern Europe perspective (tied into the origin of this research) because there are only a few months where houses are not needing heating & AC is something commercial premises use to manage temperature, that's not something a typical home has. The US and the Southern tip of the EU is a different situation.
I had misunderstood your point, but not from the Nordic perspective, but from the more fundamental level where I thought you were saying there are no savings. I now realise that you meant that the savings are so small the focus should be elsewhere.
So nothing I said is actually relevant to begin with or counts as nitpicking distraction. Sorry about that.
@shivoa If you're using, for example, a heat pump with a CoP of 3 for space heating then for every watt your TV doesn't waste your HP will need to use an extra 1/3rd of a watt saving 2/3rds of a watt.
Also, outside the heating season the saving is complete and during the heating season the saving from the TV usually happens during peak usage hours whereas heating in an efficient house can be done at other times of the day.
@edavies And we have a plan to replace central heating systems in Northern Europe (vast majority still have no multiplicative effect as they're just basic gas/oil/electric boiler units) as well as the insulation revolution on the books?
Not saying all of these efficiency things have been a total waste of time but we're fiddling in the margins (& heating offsetting headline savings means it's even less than we perceive) far more than finding a real path from 6kW to 2kW average total energy use.
@edavies If we project forward into future shape of the problem then peak usage question is rather different. It's no longer about the max number of power stations running at peak times to meet demand because we're already moving to complex questions of local energy storage & managing uneven supply (sunlight, wind etc really complicates things).
Absolutely space for storage heaters but again, 80W evening family TV vs 120W is marginal actual difference when real solutions need far more effect.
@shivoa Totally agree about the fiddling in the margins bit; overall appliance consumption is trivial compared to space heating in most high-energy-use homes (i.e., nearly all in Europe and North America).
@mplammers @roobre My sister lives out in the countryside & has one (driving underfloor heating). Ingenious engineering & definitely something to push for with new builds where viable but I am not convinced on practicalities of retrofitting many many millions of homes in the next few decades (even outside costs/materials), especially where the winters get coldest.
@shivoa @mplammers Absolutely, govt is not going to pay for the retrofitting cost, and neither will homeowners. At least in Europe, it's common for buildings to say untouched for half a century, sometimes more. Relying on "better efficiency" in a timeframe of less than, say, 1.5 centuries is unrealistic.
Honestly I think that using gas for heating only is not a bad solution at all. You have greenhouse effect gases, yes, but not nearly a worrying amount. The main problem is using it for generating electricity at great scale.
@roobre Using gas for heating is a terrible solution; as long as we persist with it we won't get close to eliminating GHG emissions.
Use for electricity generation is less critical. E.g., the UK in 2019 used 207 TWh of gas for electricity but 580 TWh for other purposes, 310 of which was domestic (space and water heating and cooking).
When the wind blows we use less gas for electricity. The same substitution doesn't happen for other uses.
@edavies Interesting, this is absolutely not the case in Spain: http://www.energiaysociedad.es/wp-content/uploads/2014/08/Capture6.png
Domestic heating is about 1/6 of the total consumption.
it is true that power generation is not that high as expected (~domestic heating), it seems that it has decreased quite a bit during the years
@fribbledom Would this 2K watts be adjusted based on where you live?
For example, people in tropical zones have less heating requirements (but more cooling needs) than people in temperate zones and both need less than people in artic zones.
Also, people in cities have lower transportation energy use requirements than people in rural areas.
Obviously it might not work out the same everywhere for aforementioned reasons, but seeing how the 2k watts are the average per capita *across* multiple countries & continents, I would say that's accounted for by definition.
@fribbledom Another question I would have about this relates to renewables and carbon-neutral fuels.
Would (personal, not grid) wind or solar power count towards the 2k limit?
I use firewood to heat, which is carbon neutral (so long as we keep planting trees); would that count?
I suspect the answer to both is 'yes', but that removes potential incentives.
@jackwilliambell @fribbledom firewood is theoretically carbon-neutral, but it's like taking out a loan - the carbon goes into the air now, and the tree growing back pays it off over its lifetime. From an emissions perspective, this is a terrible idea considering there are very good alternatives. Also, your stove is likely to be a very inefficient heat source. "Green carbon" is a very misguided idea at this point in time.
I disagree with both your specific and general points.
On the specific, my firewood isn't a 'loan'. It's previously banked carbon and, being as I have my own forest (to which I am adding trees) I am increasing the bank account over time. So, in my case it's a withdrawal. But that's me – not everyone – yes.
On the general, there are fast-growing biomass crops that produce oils and pellet fuel. These could be used instead of firewood if we created the infrastructure.
@jackwilliambell @fribbledom Then we'll discuss the general. Photosynthesis has a very low energy efficiency, and therefore, so does biomass. David Mackay discusses it here: https://www.withouthotair.com/c6/page_42.shtml
Biomass crops might work for a sparsely populated planet of nine million. It doesn't add up for nine billion.
If you live rurally, you can get solar thermal energy for *free* from air or ground source heat pumps. No need to burn anything - let it grow and suck up carbon.
I didn't read everything on your link, but it seems to me he is talking about *total* energy use, not a specific use case. (Heating) I'm unwilling to debate this case further because I don't have time to do the research right now. But I remain unconvinced by your argument.
RE: heat pumps – the best air heat pumps are only efficient at temperatures above freezing and many only work above 40f. (I do use them in shoulder season.) Ground heat pumps are inordinately expensive.
@fribbledom 2kW of fossil energy is unsustainable. By 2030, to be on course for 1.5 degrees, per-capita CO₂ emission should be around 1000kg per person per year. If you use 2.23kW of (thermal!) fossil energy, you're already there.
@fribbledom not sure if my total "embodied" energy would work out to <2k, but from my calculations I'm under 1k for electric heating, electricity use with electric car use included, but subtracting solar panel generation. I live in a very cold climate too. I think it's doable.
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