5 ms·

> Are there use cases where we must burn propane because we can’t replace that process with electricity? I think this might slot in everwhere we currently plan

by rocqua 3y ago

> Are there use cases where we must burn propane because we can’t replace that process with electricity? I think this might slot in everwhere we currently plan to use hydrogen, with the added benefit of larger storage. Here in Europe we have massive natural gas storage facilities so we can buy gas during summer to use for heating in winter. We will need something similar but renewable. If we can fill that storage with green propane, that would be amazing. It would mean we can keep our heating infrastructure. And we have an amazing use for the solar over-production in summer. Honestly tho, this sounds to good to be true.

worldsayshi 3y ago
> this sounds to good to be true. This post seems to have gotten a lukewarm reception. People are maybe extra sceptical after the lk99 dud.
konschubert 3y ago
it’s probably still more efficient to burn the gas in power plants and use heat pumps for heating. Also saves us from maintaining a residential gas network.
- wokkel 3y ago
  Maybe, but if everyone starts using heat pumps we have a problem in getting enough copper in the ground everywhere on time. So even if it's temporary (20 years or so) this is still a great solution.
  - apexalpha 3y ago
    The copper is mostly already in the ground. At least in the Netherlands it is. Apparently decades ago some absolute madman genius decided that we should put down 5 copper cables to every house and building for 3-phase power, even though they only needed one phase for the coming decades. You know. just in case.
  - teruakohatu 3y ago
    > Maybe, but if everyone starts using heat pumps we have a problem in getting enough copper in the ground everywhere on time. In New Zealand everyone uses heatpumps and there is no problem with everyone running them. Heatpumps don't use a huge amount of power even on cold days. If the grid can handle everyone cooking dinner at 6pm, it can handle heatpumps running throughout the day keeping the house warm. Fast electric car charging on the other hand draws a lot of current.
- j-a-a-p 3y ago
  At energy level a heat pump never made sense, it merits are with the fossil fuel transition. Example, a gas furnace runs at 100% efficiency (103% I believe). Heat pump at 300%. Gas to electricity to home goes at 30%. End to end they both perform at 100%. So on efficiency perspective the gas furnace equals the heat pump - but at a much lower cost. Retaining the gas network saves us from the massive investments needed in the electricity network.
  - konschubert 3y ago
    This calculus changes if you consider that on most winter days, a big part of the electricity will come from wind instead of synthetic gas.
    - j-a-a-p 3y ago
      No, your point was on using propane gas to produce electricity for heating. If your consider/complicate the equation with other energy sources (coal, wind, ...) the outcome is more random. Heat pumps do not make sense unless the energy transition into the equation (wind and solar indeed). But also then, there are major shortcomings with wind/solar currently not yet fixed. For example, my home produces appr. 12 MWh solar energy per year and the heat pumps use a similar amount. Nice balance, but too bad the is a gap of six months between the two.
  - CorrectHorseBat 3y ago
    A gas furnace isn't 100% either (103% is impossible, they lie about what 100% means), and gas to electric can go up to 60%. Heat pumps can also go over 300%, so it's definitely possible for a heat pump to beat a gas furnace.
    - j-a-a-p 3y ago
      About the gas furnaces, their efficiency exceeds 100% because of water vapour condensation. It happens both in the furnace and in the plastic exhaust pipe that exchanges heat with the outside air inflow. Gas comes in, liquid goes out and your law of thermodynamics is preserved. AFAIK the majority of housing is using this. It would surprise me if gas turbines exceed 40% on average, and then the electricity still needs to be distributed. New turbines, probably particularly when using propane could do much better indeed. My heat pumps all advertise a SCOP of around 5 for heating, and I guess the domestic hot water it would be 2.5 (don't have that, using solar for that myself). And there is a lot the installers can and will screw up, just read some user forums on this. And which consumer actually checks the real COP? So large numbers of heat pumps will perform far from optimal without somebody noticing. The 'screw up surface' of gas furnaces is much smaller. For example, ground heat sources rarely get replenished in summer (not mandatory for residential in my country).
- rocqua 3y ago
  Yes, heat pumps are more efficient. But they require lots more infrastructure. Not only is that going to be expensive and thus impopular. It will also be a delayed transition, and use up an incredible amount of resources. Not that we should do this instead of heat-pumps. We can do both. Heat-pumps in new houses and if possible when replacing old furnaces. For all the existing stuff, this could be a great stop-gap.
  - konschubert 3y ago
    I don’t disagree
  - smileysteve 3y ago
    > But they require lots more infrastructure Trenched gas lines require extensive infrastructure; while each point of use also has electrical service. How is gas less infrastructure?

by rocqua 3y ago

worldsayshi 3y ago

> this sounds to good to be true. This post seems to have gotten a lukewarm reception. People are maybe extra sceptical after the lk99 dud.

konschubert 3y ago

it’s probably still more efficient to burn the gas in power plants and use heat pumps for heating. Also saves us from maintaining a residential gas network.

wokkel 3y ago
Maybe, but if everyone starts using heat pumps we have a problem in getting enough copper in the ground everywhere on time. So even if it's temporary (20 years or so) this is still a great solution.
- apexalpha 3y ago
  The copper is mostly already in the ground. At least in the Netherlands it is. Apparently decades ago some absolute madman genius decided that we should put down 5 copper cables to every house and building for 3-phase power, even though they only needed one phase for the coming decades. You know. just in case.
- teruakohatu 3y ago
  > Maybe, but if everyone starts using heat pumps we have a problem in getting enough copper in the ground everywhere on time. In New Zealand everyone uses heatpumps and there is no problem with everyone running them. Heatpumps don't use a huge amount of power even on cold days. If the grid can handle everyone cooking dinner at 6pm, it can handle heatpumps running throughout the day keeping the house warm. Fast electric car charging on the other hand draws a lot of current.
j-a-a-p 3y ago
At energy level a heat pump never made sense, it merits are with the fossil fuel transition. Example, a gas furnace runs at 100% efficiency (103% I believe). Heat pump at 300%. Gas to electricity to home goes at 30%. End to end they both perform at 100%. So on efficiency perspective the gas furnace equals the heat pump - but at a much lower cost. Retaining the gas network saves us from the massive investments needed in the electricity network.
- konschubert 3y ago
  This calculus changes if you consider that on most winter days, a big part of the electricity will come from wind instead of synthetic gas.
  - j-a-a-p 3y ago
    No, your point was on using propane gas to produce electricity for heating. If your consider/complicate the equation with other energy sources (coal, wind, ...) the outcome is more random. Heat pumps do not make sense unless the energy transition into the equation (wind and solar indeed). But also then, there are major shortcomings with wind/solar currently not yet fixed. For example, my home produces appr. 12 MWh solar energy per year and the heat pumps use a similar amount. Nice balance, but too bad the is a gap of six months between the two.
- CorrectHorseBat 3y ago
  A gas furnace isn't 100% either (103% is impossible, they lie about what 100% means), and gas to electric can go up to 60%. Heat pumps can also go over 300%, so it's definitely possible for a heat pump to beat a gas furnace.
  - j-a-a-p 3y ago
    About the gas furnaces, their efficiency exceeds 100% because of water vapour condensation. It happens both in the furnace and in the plastic exhaust pipe that exchanges heat with the outside air inflow. Gas comes in, liquid goes out and your law of thermodynamics is preserved. AFAIK the majority of housing is using this. It would surprise me if gas turbines exceed 40% on average, and then the electricity still needs to be distributed. New turbines, probably particularly when using propane could do much better indeed. My heat pumps all advertise a SCOP of around 5 for heating, and I guess the domestic hot water it would be 2.5 (don't have that, using solar for that myself). And there is a lot the installers can and will screw up, just read some user forums on this. And which consumer actually checks the real COP? So large numbers of heat pumps will perform far from optimal without somebody noticing. The 'screw up surface' of gas furnaces is much smaller. For example, ground heat sources rarely get replenished in summer (not mandatory for residential in my country).
rocqua 3y ago
Yes, heat pumps are more efficient. But they require lots more infrastructure. Not only is that going to be expensive and thus impopular. It will also be a delayed transition, and use up an incredible amount of resources. Not that we should do this instead of heat-pumps. We can do both. Heat-pumps in new houses and if possible when replacing old furnaces. For all the existing stuff, this could be a great stop-gap.
- konschubert 3y ago
  I don’t disagree
- smileysteve 3y ago
  > But they require lots more infrastructure Trenched gas lines require extensive infrastructure; while each point of use also has electrical service. How is gas less infrastructure?