Comment by tialaramex
2 days ago
More, but not as much more as people often naively expect because it turns out converting liquid fuel into motion by burning/ exploding the fuel isn't very efficient on a small scale whereas electric motors are very efficient, so 1TW year of "People driving to work" in ICE cars does not translate into needing 1TW year extra electricity generation if they have electric cars instead, let alone 1TW year of extra network capacity to deliver it.
Where we're replacing fossil fuel heat with a heat pump we don't get that efficiency improvement from motors - burning fuel was 100% efficient per se, but the heat pump is > 100% efficient in those terms because it's not making heat just moving it.
Nuclear is much less popular than almost any generation technology, so you're fighting a significant political battle to make that happen.
We need a lot more. Right now only about 25 to 33 pc of our energy consumption is electric. Some of the rest will get significant efficiency benefit like you mention — cars, building heating, etc. Others, much less so— high temperature industrial heat, long distance transport, etc.
Reaching current nighttime use with storage and wind and existing hydro looks infeasible, and we need a minimum of twice as much.
Power to gas (and back to power or to mix with natural gas for existing uses) is probably a part of this, but nuclear improves this (allowing there to be less of it and allowing the electrolysis cells to be used for a greater fraction of the day.
People have run the numbers. We need about 30% more. Which is a lot, but it's spread over 20-30 years, so it's not a lot each year.
Does that also account for industrial chemical processes that don't have a simple power-energy exchange? Stuff like making fertilizer or solvents and the like do take a lot of electrical power currently, but will require even more rarely accounted for energy to create base reagents without fossil fuels. Like fertilizer already uses 1% of global electricity today, but if we want to create nitrogen fertilizers without fossil fuel sources, it takes up to a 10 times increase in energy requirements to synthesize from the air making it rise to near 10% of current electrical generation. Many oils are used in mechanical components are irreplaceable and have to be sourced, but to do it without fossil fuels and synthesize from organic materials also require a lot more energy than we use to purify or synthesize from fossil fuels. And the same is true of many solvents.
Its usage is technically accounted for in fossil fuel extraction numbers, but generally ignored when people are accounting for total electrical generation and the usage of fuels as heat sources.
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US electric demand is 4 trillion kWh per year. Moving to EVs alone will be about 1 trillion kWh more. And that is leaving out transport, building heat, and industrial use.
I suspect you are quoting an EV-only number.
Alternatively, you might be looking at how much electricity demand is expected to increase if we maintain our current trajectory and don’t aggressively decarbonize.
30% more is just wrong.
Canada needs between double and triple the electricity generation of today. Canada may not be the best example but there is a lot of uncertainty, especially around climate. it is not unreasonable to expect that places like Europe and India will increasingly add air conditioning, pushing the required grid capacity to double today's.
What are the caveats of your 30% figure?
https://natural-resources.canada.ca/energy-sources/powering-...
Building heating won’t see much increase in efficiency from going electric compared to a high efficiency gas furnace.
A 4x efficiency bump is fairly easy (.9 efficient gas to 3.6 COP heat pump). Older non-condensing boilers (or modern condensing boilers run too hot) are more like .8 when new and messured at .6 in real life circumstances.
Even at the high end efficiency, this is enough that you can burn the gas centrally in a generator, lose 40-60% of it as heat as is standard with fossil electricity generation, lose a few percent more electricity in transmission and still come out ahead overall.
And of course, that's a lower bound as you'd ideally be generating electricity from other sources like solar and wind and battery and keeping the gas generators for when needed, making use of the giant scale gas storage most countries already have.
Hrm? Heat pumps are multiples more efficient than gas.