this post was submitted on 03 Sep 2024
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Discussion of climate, how it is changing, activism around that, the politics, and the energy systems change we need in order to stabilize things.

As a starting point, the burning of fossil fuels, and to a lesser extent deforestation and release of methane are responsible for the warming in recent decades: Graph of temperature as observed with significant warming, and simulated without added greenhouse gases and other anthropogentic changes, which shows no significant warming

How much each change to the atmosphere has warmed the world: IPCC AR6 Figure 2 - Thee bar charts: first chart: how much each gas has warmed the world.  About 1C of total warming.  Second chart:  about 1.5C of total warming from well-mixed greenhouse gases, offset by 0.4C of cooling from aerosols and negligible influence from changes to solar output, volcanoes, and internal variability.  Third chart: about 1.25C of warming from CO2, 0.5C from methane, and a bunch more in small quantities from other gases.  About 0.5C of cooling with large error bars from SO2.

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[–] silence7 7 points 1 week ago* (last edited 1 week ago) (2 children)

Yes, heat pumps are really common in new EVs, but I'm not sure if it's most worldwide or not.

Your idea about thermal storage is interesting; I'm very much unclear on whether it would make sense to do that or simply have a bigger battery or some amount of insulation on the passenger compartment.

[–] futatorius@lemm.ee 5 points 1 week ago (1 children)

Adding thermal storage would require mass to be added, unless some existing component could be converted to dual-purpose. More mass in an EV means lower range and an increase in the already high vehicle weight.

[–] jol@discuss.tchncs.de 2 points 1 week ago

And I can't imagine the thermal accumulator + insulation would have a higher energy intensidensity than just the battery alone.

[–] ptz@dubvee.org 4 points 1 week ago* (last edited 1 week ago) (1 children)

After thinking about it a bit more, a bigger battery would probably be the most practical.

Using my hybrid as a reference point (it uses the whole engine as a thermal mass for heat storage), the stored heat only lasts about 5-10 minutes at most before the engine kicks back on to warm it up again (the controller lets it cool to the lowest "operating" temperature for efficiency). If it could use the full stored heat in the engine, it would probably only be good for another 5 minutes at most. Granted, it's using that heat directly with a traditional heater core rather than feeding a heat pump.

Given that it would be used seasonally and be "dead" weight the rest of the year, I'm not sure adding a thermal mass would be all that practical unless it's something that can be heavily insulated and super-heated beyond the temperatures engines run at or has an additional year-round use.

The only downside to a larger battery is purely a human perception/marketing issue. The extra battery capacity would most likely be advertised in the range, and people would still probably be upset about the reduced range in the winter. It would have to be, ideally, not factored into the range and act as a "reserve" capacity.

Regardless, yeah, better cabin insulation would also help, to a point.

I just work around the problem by not running the heat most of the time (barring the need to defrost/defog). Most of my trips are short, so I just wear my coat/gloves and deal with the cold lol.

[–] skuzz@discuss.tchncs.de 2 points 1 week ago

How about using the thermal mass for both heating and cooling? Too bad EVs don't have throwaway power like hybrids, could use the excess to heat/cool the mass as necessary. Probably still not as efficient as raw power storage.