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Using electricity to heat buildings should be one of the last steps to take, after almost everything else using energy is renewable. Electricity is a precious f

Using electricity to heat buildings should be one of the last steps to take, after almost everything else using energy is renewable. Electricity is a precious form of energy, while heat is primitive. Converting in both directions is not lossless, so you want to keep the precious form. The author makes it seem like that the negative prices are constant, which is not the case. Germany also does not have 100% renewable energy. Once you have an electric heater at your home, you will be using electric energy generated by burning coal to heat your home. It also does not solve the problem of the German electricity market, which is mostly that renewable energy is not steady. Power is not distributed evenly across space and time. So you need to store the energy and move it from North to South. But storage and transmission lines are lacking to say the least. One intermediate strategy you could take, would be to convert abundant electric energy to hydrogen, which you can feed into the already existing natural gas pipes and burn inside the already existing gas heaters, the author is criticizing. This way you would solve both problems (missing network and missing storage) at the same time.

nostromo 7y ago
I couldn't disagree more. Electric heating via heat pump is ridiculously efficient and has a much bigger bang for your carbon-reducing buck than anything else a homeowner can do.
- endorphone 7y ago
  Bizarre that you were downvoted, when your point is spot on. Yes, heating with a big electric radiator is wasteful. Heating with a heat pump, on the other hand, is fantastically efficient.
  - Gibbon1 7y ago
    Yes if you analyze it thermodynamically heating via natural gas is terrible. You're taking a high quality source of energy (a flame at 3500 degF) and turning it into the thermodynamic equivalent of garbage (hot air at 70 degF). All the work it could have done (say generating electricity) is tossed.
    - allendoerfer 7y ago
      There is so much natural gas in Sibiria, due to climate change warming the permafrost, it will just escape into the atmosphere, before we come close to burning it all.
    - usrusr 7y ago
      Which is where district heating comes in. Utilities, who unlike households are fully exposed to fluctuations of the electricity market, are increasingly switching their cogen pants to decoupled operation where large heat storage elements are added so that the plant can run as a peaker plant. It's not glamorous because they are still burning fossil fuel, but it's a huge improvement not only over separate burning for heat but also over synchronous cogen that would follow the heart demand. It's even a reasonable long term investment because a fully decarbonized economy would shave supply peaks with power-to-gas.
      - makomk 7y ago
        Yeah, in practice I think district heating is probably the only way to actually improve on the thermodynamic efficiency of just taking all that high-grade energy and converting it straight to low-grade heat. Running heat pumps off electricty from non-cogeneration gas plants can only roughly match the efficiency of gas heating, and smaller-scale CHP setups have efficiency losses that make them questionable.
      - piceas 7y ago
        An example from Hamburg is the Energiebunker. I went on a tour a few years ago which I can recommend. One comment was they had trouble with the local landlords not wanting to take up the offer resulting in poor utilisation. https://www.internationale-bauausstellung-hamburg.de/en/projects/energiebunker/projekt/energy-bunker.html https://www.internationale-bauausstellung-hamburg.de/en/proj...
- gsich 7y ago
  The term "electric" does mean something different when it comes to heating. Not a heat pump, but large resistors with low resistance.
- johnr2 7y ago
  > Electric heating via heat pump is ridiculously efficient Strictly speaking that's "electrically assisted" heating. What most people refer to as electric heating is the conversion of electricity directly into heat, eg. by a resistive element.
  - Dylan16807 7y ago
    You're claiming that when mostly people say "electric heating" they are specifically excluding heat pumps? Do you have something to back that up?
    - endorphone 7y ago
      It is a bit of gatekeeping that has little relation with reality. When people say that their home is heated by natural gas, they mean that they have a supply of natural gas, and that is the consumable they use / pay for, not the specific chemical process when it is oxidized. Similarly, when people say they heat their home with electricity, whether it's a heat pump or electric radiators is just a secondary possibility. I heat my home with electricity and it's a ground-source heat pump. If someone has some weird hangup or ignorance about that, that's on them. If someone said that they cooled their home in the winter with "electricity assistance" I think everyone would rightly laugh.
    - johnr2 7y ago
      > You're claiming that when mostly people say "electric heating" they are specifically excluding heat pumps? No, just pointing out the usual definition of electric heating. A heat pump doesn't necessarily even use electricity. The mechanical power for the compressor (assuming a refrigerant based heat pump) could come from anywhere.
- Retric 7y ago
  The issue with heat pumps is you may need far less heat at 15c when their very efficient than at -15c when their not. Couple that with the losses from heat to electricity at power plants and burning natural gas at home is about as efficient on average depending on your area. So, it really does depend on how cold it gets where you are if it’s better to burn fuel at home or at a powerplant. PS: Solar hot water heaters are generally the best overall option any place heat pumps are actually efficient.
  - xnyan 7y ago
    When I run the numbers, a solar water heater does not work out for me. In order for me to eliminate my electric heater I would need an active (somewhat more costly) solar heating system which run ~$4k the lower end if you include the cost of installation. At a rate of about $500 a year in water heating costs that's a 8 year payback timeframe for a device that has a 5 year warranty (more expensive models have longer warranties).
    - Retric 7y ago
      The best time to do an install is when you’re looking at buying a water heater either way. Thus significantly reducing the price premium. Further, sizing a system to also handle home heating is generally where the real savings takes place. As to warranty, they generally last well past that point. You may be replacing a part or to at ~10 years, but a 20+ year lifespan is common depending on the model and your water hardness.
    - aftbit 7y ago
      Can you do solar preheat as a retrofit to an existing electric (or natural gas) hot water heater? Coil some flexible water line in a plywood box, spray paint it all black, put a plexiglass lid on, caulk it up, and lay it out in the sun. Feed cold water through it before it hits your hot water heater. It probably would not be as efficient as a commercial solution, but it would be very cheap. Don't forget about water safety, backflow valves, or local plumbing and building codes. Or winter - would want a bypass valve for flushing and draining it.
- allendoerfer 7y ago
  I don't have anything against heat pumps. I just don't think that they would solve the problems the article is talking about. I would put heat pumps all over the place, once electric energy, transportation etc. are 100% renewable.
raxxorrax 7y ago
I don't know why you are downvoted because this is pretty correct. Electricity is the most valuable form of energy that currently should only be used for heating in exceptional cases if no alternatives are present.
- allendoerfer 7y ago
  In my experience renewable energy, electricity and nuclear are highly controversial topics on HN. Like with this post, I often get heavily up- and downvoted by different camps. It correlates with time of day, so I suspect I have a European perspective.

nostromo 7y ago

I couldn't disagree more. Electric heating via heat pump is ridiculously efficient and has a much bigger bang for your carbon-reducing buck than anything else a homeowner can do.

endorphone 7y ago
Bizarre that you were downvoted, when your point is spot on. Yes, heating with a big electric radiator is wasteful. Heating with a heat pump, on the other hand, is fantastically efficient.
- Gibbon1 7y ago
  Yes if you analyze it thermodynamically heating via natural gas is terrible. You're taking a high quality source of energy (a flame at 3500 degF) and turning it into the thermodynamic equivalent of garbage (hot air at 70 degF). All the work it could have done (say generating electricity) is tossed.
  - allendoerfer 7y ago
    There is so much natural gas in Sibiria, due to climate change warming the permafrost, it will just escape into the atmosphere, before we come close to burning it all.
  - usrusr 7y ago
    Which is where district heating comes in. Utilities, who unlike households are fully exposed to fluctuations of the electricity market, are increasingly switching their cogen pants to decoupled operation where large heat storage elements are added so that the plant can run as a peaker plant. It's not glamorous because they are still burning fossil fuel, but it's a huge improvement not only over separate burning for heat but also over synchronous cogen that would follow the heart demand. It's even a reasonable long term investment because a fully decarbonized economy would shave supply peaks with power-to-gas.
    - makomk 7y ago
      Yeah, in practice I think district heating is probably the only way to actually improve on the thermodynamic efficiency of just taking all that high-grade energy and converting it straight to low-grade heat. Running heat pumps off electricty from non-cogeneration gas plants can only roughly match the efficiency of gas heating, and smaller-scale CHP setups have efficiency losses that make them questionable.
    - piceas 7y ago
      An example from Hamburg is the Energiebunker. I went on a tour a few years ago which I can recommend. One comment was they had trouble with the local landlords not wanting to take up the offer resulting in poor utilisation. https://www.internationale-bauausstellung-hamburg.de/en/projects/energiebunker/projekt/energy-bunker.html https://www.internationale-bauausstellung-hamburg.de/en/proj...
gsich 7y ago
The term "electric" does mean something different when it comes to heating. Not a heat pump, but large resistors with low resistance.
johnr2 7y ago
> Electric heating via heat pump is ridiculously efficient Strictly speaking that's "electrically assisted" heating. What most people refer to as electric heating is the conversion of electricity directly into heat, eg. by a resistive element.
- Dylan16807 7y ago
  You're claiming that when mostly people say "electric heating" they are specifically excluding heat pumps? Do you have something to back that up?
  - endorphone 7y ago
    It is a bit of gatekeeping that has little relation with reality. When people say that their home is heated by natural gas, they mean that they have a supply of natural gas, and that is the consumable they use / pay for, not the specific chemical process when it is oxidized. Similarly, when people say they heat their home with electricity, whether it's a heat pump or electric radiators is just a secondary possibility. I heat my home with electricity and it's a ground-source heat pump. If someone has some weird hangup or ignorance about that, that's on them. If someone said that they cooled their home in the winter with "electricity assistance" I think everyone would rightly laugh.
  - johnr2 7y ago
    > You're claiming that when mostly people say "electric heating" they are specifically excluding heat pumps? No, just pointing out the usual definition of electric heating. A heat pump doesn't necessarily even use electricity. The mechanical power for the compressor (assuming a refrigerant based heat pump) could come from anywhere.
Retric 7y ago
The issue with heat pumps is you may need far less heat at 15c when their very efficient than at -15c when their not. Couple that with the losses from heat to electricity at power plants and burning natural gas at home is about as efficient on average depending on your area. So, it really does depend on how cold it gets where you are if it’s better to burn fuel at home or at a powerplant. PS: Solar hot water heaters are generally the best overall option any place heat pumps are actually efficient.
- xnyan 7y ago
  When I run the numbers, a solar water heater does not work out for me. In order for me to eliminate my electric heater I would need an active (somewhat more costly) solar heating system which run ~$4k the lower end if you include the cost of installation. At a rate of about $500 a year in water heating costs that's a 8 year payback timeframe for a device that has a 5 year warranty (more expensive models have longer warranties).
  - Retric 7y ago
    The best time to do an install is when you’re looking at buying a water heater either way. Thus significantly reducing the price premium. Further, sizing a system to also handle home heating is generally where the real savings takes place. As to warranty, they generally last well past that point. You may be replacing a part or to at ~10 years, but a 20+ year lifespan is common depending on the model and your water hardness.
  - aftbit 7y ago
    Can you do solar preheat as a retrofit to an existing electric (or natural gas) hot water heater? Coil some flexible water line in a plywood box, spray paint it all black, put a plexiglass lid on, caulk it up, and lay it out in the sun. Feed cold water through it before it hits your hot water heater. It probably would not be as efficient as a commercial solution, but it would be very cheap. Don't forget about water safety, backflow valves, or local plumbing and building codes. Or winter - would want a bypass valve for flushing and draining it.
allendoerfer 7y ago
I don't have anything against heat pumps. I just don't think that they would solve the problems the article is talking about. I would put heat pumps all over the place, once electric energy, transportation etc. are 100% renewable.

raxxorrax 7y ago

I don't know why you are downvoted because this is pretty correct. Electricity is the most valuable form of energy that currently should only be used for heating in exceptional cases if no alternatives are present.

allendoerfer 7y ago
In my experience renewable energy, electricity and nuclear are highly controversial topics on HN. Like with this post, I often get heavily up- and downvoted by different camps. It correlates with time of day, so I suspect I have a European perspective.