26 ms·

For heating, you are probably better off converting to electricity (burning or fuel cell) and driving a high-COP heat pump. Good heat pumps are ~250-300% "effic

For heating, you are probably better off converting to electricity (burning or fuel cell) and driving a high-COP heat pump. Good heat pumps are ~250-300% "efficient" at "converting" electricity to heat. (Efficiency isn't in the Carnot sense, and heat pumps move heat rather than generating heat... Semantics, but point stands.) For example: I recall reading that it is more efficient (ie BTUs generated) to use natural gas peaker plants generating electricity to drive a heat pump than to run a furnace. (Except at very low temps where COP drops quickly.)

midasuni 4y ago
A modern heat pump claims a cop in the 4.8 range It’s more efficient to burn the gas in a grid power station, convert to electricity, and use the electricity to drive the heat pump, then it is to burn the gas for heat directly.
- serpix 4y ago
  And that is why heating with gas needs to die a quick death.
- yvdriess 4y ago
  Watch out, cop ranges wildly (1.1-5+) depending on the type of heat pump, output temperature and intake temperature. Ideal are water-water heat pumps connected to a deep well, but these cannot be installed everywhere and carry a significant (roughly double) capital investment. Air-water heat pumps are very sensitive to outside air temperature and output temperature. Low-temperature heating (30-40C) still gets an OK ~2-2.5 cop in freezing temperatures, but sanitary water (65deg C) tanks the efficiency significantly. Another consideration is that you lose efficiency in converting chemical to electrical energy, plus there is a higher transport and distribution loss to factor in.
  - midasuni 4y ago
    Specs on this one https://www.panasonicproclub.com/uploads/IE/catalogues/PIR%204P%20AQ%20MONOBLOCK%20J%2020.pdf https://www.panasonicproclub.com/uploads/IE/catalogues/PIR%2... Show a 4.5 cop for a 7C-35C range, dropping to 1.8 for a -7 to 55C range. For 2C to 35C it’s still a cop over 3

midasuni 4y ago

A modern heat pump claims a cop in the 4.8 range It’s more efficient to burn the gas in a grid power station, convert to electricity, and use the electricity to drive the heat pump, then it is to burn the gas for heat directly.

serpix 4y ago
And that is why heating with gas needs to die a quick death.
yvdriess 4y ago
Watch out, cop ranges wildly (1.1-5+) depending on the type of heat pump, output temperature and intake temperature. Ideal are water-water heat pumps connected to a deep well, but these cannot be installed everywhere and carry a significant (roughly double) capital investment. Air-water heat pumps are very sensitive to outside air temperature and output temperature. Low-temperature heating (30-40C) still gets an OK ~2-2.5 cop in freezing temperatures, but sanitary water (65deg C) tanks the efficiency significantly. Another consideration is that you lose efficiency in converting chemical to electrical energy, plus there is a higher transport and distribution loss to factor in.
- midasuni 4y ago
  Specs on this one https://www.panasonicproclub.com/uploads/IE/catalogues/PIR%204P%20AQ%20MONOBLOCK%20J%2020.pdf https://www.panasonicproclub.com/uploads/IE/catalogues/PIR%2... Show a 4.5 cop for a 7C-35C range, dropping to 1.8 for a -7 to 55C range. For 2C to 35C it’s still a cop over 3