We have a heat pump with SOCP 5, but are still using 30kWh per day now.

zeeveener 8 hours ago | parent | next [-]

On most modern EVs, that's at least 3 days worth of power if the vehicle is not being driven. Larger vehicles naturally have far larger batteries.

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darkwater 5 hours ago | parent [-]

Mmmh no? 90kWh battery packs are not that common. An M3 or MY LR AWD have an 82kWh. Some Mercedes and some Chinese model have a 100+kWh battery but the most common setup is between 60 and 70.

Anyway I agree that in emergency conditions it can go a looong way for a house.

	▲	sroussey 2 hours ago \| parent [-]
		My bmw has 108

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masklinn 7 hours ago | parent | prev | next [-]

That's 2-3 days worth without changing your use pattern, which surely you would do if you expected a long blackout period?

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pmontra 7 hours ago | parent | prev [-]

Is that 30 kW each hour of the day or 30 kW per day?

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alex43578 7 hours ago | parent | next [-]

30 kWh per day, while a clunky unit, is what most people would understand when talking about home consumption. It’ll be what their utility typically reports, how you’d want to size a battery, etc.

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gertrunde 7 hours ago | parent | prev | next [-]

Sort of neither?

It's 30kW for one hour.

(Or 1.25kW for 24 hours, or however you prefer).

[Link: https://en.wikipedia.org/wiki/Kilowatt-hour]

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numpad0 5 hours ago | parent | next [-]

It's like you had a faucet with cross section of 2 square inches, and 15 seconds with that faucet wide open would fill a jug. That jug holds 30 squareinches-seconds of water.

You may then use that water over the course of a day. That's 30 sqin-sec per day. That is not 30 square inches for a whole day. It's second per day.

Or watt hour per week or whatever.

Yes, it can be described like 0.00034722 sqin/day, and that corresponds to no physical object and that would be largely useless.

Why not Joules or Liters? Because that's complicated for anything electrical.

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OJFord 7 hours ago | parent | prev [-]

Pretty sure GP understands that, their point being you can't just wave away 'per unit time' when talking about it relative to generation, it matters.

	▲	buran77 6 hours ago \| parent \| next [-]
		"30kW per day" makes no sense. It's like saying "100km/h per day". W is a unit of power, Wh is a unit of energy. It's unintuitive because a guy named Watt decided "Joule per second" is Watt, so the intuitive units Joule and Joule per second got turned on their head to W times hour and Watt. This is opposite to usual intuition of distance and speed for example, km and km/h. If I redefined the km/h to a "tick", then a km would become "tick times hour". If you want a "better than nothing" but imperfect analogy, Wh is how much water you have in a bottle, and W is how quickly you can get the water out.
	▲	SamBam 7 hours ago \| parent \| prev [-]
		"30kWh per day" isn't waving away anything. 30kW is a rate. 30kWh is a measure of energy, about 100MJ. 30kWh/day is a rate again, 100MJ/day. It seems clunky, but it's a way energy usage in a house is typically measured.

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7 hours ago | parent | prev [-]

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