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Single vs. three phase for heat pump, EV and appliances

Mars · 2024-03-12T14:16:21Z

We're considering the electrical needs for our house which currently has a 100A fuse on the consumer board. We have an 18kW heat pump and various other appliances (fridges, TVs, routers, distribution pumps, etc.). We're also thinking about adding an electric vehicle (EV) charger in the future. Could you advise on whether a single-phase or three-phase electricity supply would be best suited for our situation? Additionally, what are the key differences between single-phase and three-phase electricity in the context of residential use, especially considering the high electrical demand from the heat pump and the potential addition of an EV charger? In terms of "upgrading" to three phase, it is a matter of splintering off from the power lines to our house or it is more complex than that?

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Anonymous 5011

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29/08/2024 1:17 pm

Never understood the need for three phase in a domestic situation. Even with an electric car, you charge slowly overnight doesn't need rapid charge.

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GunboatDiplomat

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29/08/2024 1:57 pm

Larger heat pumps, heated pools, steam rooms and hot tubs in top of a normal domestic load were examples that came up today. I had a three phase supply in my childhood home but that was because we had a kiln - so not a normal domestic load!

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Derek M

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29/08/2024 2:14 pm

Posted by: @gunboatdiplomat

↑

Larger heat pumps, heated pools, steam rooms and hot tubs in top of a normal domestic load were examples that came up today. I had a three phase supply in my childhood home but that was because we had a kiln - so not a normal domestic load!

Please correct me if I am wrong, but I was under the impression that the objective was to save our planet from global warming by using LESS energy.

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Toodles

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29/08/2024 2:29 pm

@derek-m Certainly less ‘dirty’ energy anyway! Toodles.

Toodles, he heats his home with cold draughts and cooks his food with magnets.

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Anonymous 5011

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29/08/2024 2:41 pm

Posted by: @gunboatdiplomat

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childhood home

Mine had coal fire, doesn't mean I would have one now.

If your home is listed as grade 1 then you have a plausible excuse for a very large heat pump, otherwise get more insulation, reduced drafts.

Pools should be heated by a heat pump, so they can be very small anyway.

So still see no need for 3 phase.

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Derek M

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29/08/2024 2:42 pm

Posted by: @toodles

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@derek-m Certainly less ‘dirty’ energy anyway! Toodles.

I suppose that is okay then.

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Toodles

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29/08/2024 3:18 pm

@derek-m Well, preferably no dirty energy and only as much clean energy as might be justified. As the King who had to cut down on his staff is reputed to have said ‘Can’t a King have a biscuit?😉 Toodles.

Toodles, he heats his home with cold draughts and cooks his food with magnets.

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Mike Patrick

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30/08/2024 11:50 am

@derek-m That''s the irony of electric vehicles isn't it? Being heavier than ICE ones they need more energy to move around. The extra energy needs to be from renewable sources for them to make sense.

Mike

Grant Aerona HPID10 10kWh ASHP

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Toodles

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30/08/2024 12:14 pm

@mike-patrick I think the 745.7 watts of renewable energy required for the electric vehicle is probably a more efficient horsepower than one derived from a probably less efficient ICE in a vehicle? (What I’m trying to say is: I don’t know the efficiency of an ICE!) Regards, Toodles

Toodles, he heats his home with cold draughts and cooks his food with magnets.

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Majordennisbloodnok

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31/08/2024 8:01 am

Very roughly speaking, a modern ICE vehicle is up to about 25% efficient whilst a comparable EV is about 75% efficient. The EV then has an extra complication that there are losses of between 5 and 10% in the charging process itself, but that still makes for a hugely more energy efficient vehicle despite the heavier weight.

105 m2 bungalow in South East England
Mitsubishi Ecodan 8.5 kW air source heat pump
18 x 360W solar panels
1 x 6 kW GroWatt battery and SPH5000 inverter
1 x Myenergi Zappi
1 x VW ID3
Raised beds for home-grown veg and chickens for eggs

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Toodles

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31/08/2024 9:45 am

@majordennisbloodnok Thank you for confirming my thoughts Major. Regards, Toodle.

Toodles, he heats his home with cold draughts and cooks his food with magnets.

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bontwoody

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31/08/2024 11:36 am

@mike-patrick Actually Mike, my BMW i3 is lighter than an equivalent ICE car, much to my friends annoyance when he was trying make a point about EV weights, so its not a given.

However the real advantage of EVs over ICEs is regenerative breaking where most of the energy that is just lost in slowing down an ICE is recouped back into the battery in an EV.

That is a major area where EVs increase their efficiency over ICEs as well as in the conversion process where ICEs are very poor efficiency.

House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
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