• evranch@lemmy.ca
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    11 months ago

    Sadly, no. Your electric heater is 100% efficient, yes, but that thermal power plant is lucky to hit 50%, especially if it’s old tech which many are.

    On the other hand, burning natural gas at the point of use can be done at 95% efficiency by a condensing boiler or furnace.

    That’s not even taking into account transmission losses. With them in play, even a ground-source heat pump has higher emissions than a natural gas furnace.

    The only way electrification of heating makes sense is to decarbonise the grid, which should be the first priority. Nuclear and hydro baseload with solar/wind peaking and elastic loads and load shedding to take advantage of the variable supply.

    • AA5B@lemmy.world
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      11 months ago
      1. You can’t complain about electricity loses without considering natural gas losses, especially the affect of methane on global warming
      2. Why would you have to do one thing, then the other? Everyone agrees we need to both electrify homes and de carbonize the grid. However we also realize both are a long complex, expensive transition with many many pieces. It only makes sense to do both at the same time: an electrified house already reduces its impact on global warming, and just keeps getting better over time as the grid continues to be de-carbonized
    • ratman150@sh.itjust.works
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      11 months ago

      Since we’re talking efficiency I’m sure you also know that several smaller consumers are gonna be far less efficient than one big consumer.

      I’m not sure where you’re getting that information about a heat pump being worse than a literal fire burning furnace but that fire burning furnace is still less efficient as a small appliance than the power generation. What’s also important here is the heat pump can run on natural gas electricity, nuclear electricity, hydro etc. it is energy agnostic which the furnace is absolutely not.

      • evranch@lemmy.ca
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        11 months ago

        several smaller consumers are gonna be far less efficient than one big consumer

        That’s the point I’m making. It’s counterintuitive. They are actually far more efficient, even though that “feels wrong”.

        Thermal power generation is limited by the Rankine cycle https://en.m.wikipedia.org/wiki/Rankine_cycle with a MAXIMUM efficiency of only 42%.

        You are burning fuel, turning a temperature differential into motion, into electricity, transmitting the electricity, then turning it back into a temperature differential.

        In the specific application of heating, it makes far more sense to burn the fuel on site, where you are running at far lower temperatures and capable of condensing the exhaust to hit 95% efficiency.

        I’ve worked with heat pumps, even built my own custom unit and I know that with the right refrigerants, low temperature distribution and oversized ground loops you can hit as high as a COP of 7. But the average affordable crappy air sourced unit is more like 2-3 and in a Canadian winter will not function at all, falling back on resistive heating at COP 1. And let’s face it, nobody has $20-50k for an amazing oversized ground sourced system and a rework to hydronic floors. They’re buying a reversible mini-split, DIY installing it and being disappointed when their heating bill goes up.

        So with a COP of 2 and a power plant efficiency below 50% you are not even back to where you started if you were just burning the fuel in a furnace. And that’s best case, perfect conditions at the plant, no transmission losses, warm day, no Iosses in the heat pump.

        It gets worse if your power comes from burning coal like ours does.

        I’m just saying there’s no perfect drop-in solution, you can’t just handwave heat pumps in as a magic problem solver. In many cases there are bigger gains to be had from efficient furnaces than a massive electrification program, at least in the short to mid term.

        • nikita@sh.itjust.works
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          11 months ago

          Thanks for your comment. Very informative and insightful.

          However, your argument only works when electricity is sourced from 100% non renewable sources. If your city power uses some hydro, nuclear or other renewable sources, the efficiency of electric appliances goes up and will likely be at least comparable with the average gas powered home appliance. And it will keep going up as power plants become renewable and thermal plants are decomissioned.