4 ms·

I don't see any actual comparison to fossil fuels. They use a measure, COP, which is coefficient of performance, which doesn't seem applicable to fossil fue

I don't see any actual comparison to fossil fuels. They use a measure, COP, which is coefficient of performance, which doesn't seem applicable to fossil fuel furnaces or if applied there would give those furnaces an enormous COP number. Anyways, I don't understand the need to draw these types of "total" comparisons. If you have reliable electricity, a heat pump is probably great, if you don't, then fossil fuels are clearly the way to go. There is no "one size fits all" energy strategy.

francisofascii 3y ago
Using COP is a easy way to compare heat pump efficiency to conventional heating methods. It is a multiple of the amount of heat energy output given the electricity energy used. A fossil fuel boiler is always less than 1 (usually 0.6-0.8) since it is never 100% efficient at converting the fuel energy to heat energy. Your electric space heater has a COP of exactly 1. So when you see the COPs in the 4-6 range, you get a good sense of how much more efficient heat pumps are.
- gruez 3y ago
  > A fossil fuel boiler is always less than 1 (usually 0.6-0.8) since it is never 100% DOE mandates 80% efficiency for new furnaces, and high efficiency units are in the 90-95% range.
- paul_f 3y ago
  The COP for a heat pump drops as the temperature decreases. The climate should have a large impact on the choice of technology. Here in Florida it is a no brainer, everyone has a heat pump for the cool winter days. In Minnesota, it is a non starter.
  - francisofascii 3y ago
    The article is pointing out that heat pumps today can still be more efficient down to -20 C (-4F).
  - sbradford26 3y ago
    It depends on what else you have available. If you have natural gas available at your house then a heat pump is probably not the most economical choice. Here in New Hampshire though NG is not available at many homes and a cold weather heat pump ends up being the cheapest option versus heating oil or propane.
- akira2501 3y ago
  So, this is based on the assumption that electricity coming into the home is 100% efficient and none of the systems inefficiencies in power generation or delivery need to be accounted for, the way they are in fossil fuels? That doesn't seem particularly useful.
  - francisofascii 3y ago
    Right, this measure is more for consumers and does not take into account generation or delivery. It is especially useful when comparing heat pumps to electric resistance heat, which is often the backup heat source. If the COP falls below one, you switch to resistance heat. But this article is saying heat pumps built today can operate well over 1 at very low temps.
lazide 3y ago
Because it’s delusion. BTUs from hydrocarbon gases (and hydrocarbons in general) are phenomenal, and Natural gas is generally more of a waste product from oil extraction than anything, so is dirt cheap. The equipment required to use them (a typical furnace or boiler) is also cheap, low maintenance, well understood, and widely deployed everywhere. Most cold climates use fossil fuel heating. Heat pumps aren’t terrible, and are vastly more efficient than resistive heat for heating. If the only energy source is cheap and electric, it’s an easy win. But for areas already widely using fossil fuel heating (such as Germany), switching to heat pumps will increase electrical demand by at least an order of magnitude - best case - and since peak heating demand tends to happen when it’s winter, better have adequate storage too. Germany also has very expensive electricity, so it will dramatically increase costs unless extensive amounts of insulation are also done, increasing capex. So, if we look at price, and especially if we include capex, it’s only competitive in niche contexts or if we expect fossil fuel costs to be immediately and rapidly increased 4-5x. Even then, if done widely it will break a lot of things unless there is a lot of grid upgrades too. Increasing capex. It’s why Germany is struggling to switch off. They’re not the only ones.
- no_wizard 3y ago
  German energy policy baffles me. The were once the leader in nuclear energy. They really should have kept that lead, and built more nuclear plants and aggressively switched to electric first solutions such as heat pumps, EVs etc. Instead, they are winding down their nuclear power plants, and increasing their reliance on fossil fuels in the near to mid term, at the very least, which means issues like this will plague them for some time. No idea why they didn't pursue more energy independence when they had the chance
  - lazide 3y ago
    It boils down to feeling good about helping the planet, without doing the math or recognizing the hard realities IMO. When the policy was started, the USSR had fallen, the world was on the upswing, etc. etc. optimism, enthusiasm, etc. These issues were all called out at the time.
  - 3y ago
deleted 3y ago
[deleted]

francisofascii 3y ago

Using COP is a easy way to compare heat pump efficiency to conventional heating methods. It is a multiple of the amount of heat energy output given the electricity energy used. A fossil fuel boiler is always less than 1 (usually 0.6-0.8) since it is never 100% efficient at converting the fuel energy to heat energy. Your electric space heater has a COP of exactly 1. So when you see the COPs in the 4-6 range, you get a good sense of how much more efficient heat pumps are.

gruez 3y ago
> A fossil fuel boiler is always less than 1 (usually 0.6-0.8) since it is never 100% DOE mandates 80% efficiency for new furnaces, and high efficiency units are in the 90-95% range.
paul_f 3y ago
The COP for a heat pump drops as the temperature decreases. The climate should have a large impact on the choice of technology. Here in Florida it is a no brainer, everyone has a heat pump for the cool winter days. In Minnesota, it is a non starter.
- francisofascii 3y ago
  The article is pointing out that heat pumps today can still be more efficient down to -20 C (-4F).
- sbradford26 3y ago
  It depends on what else you have available. If you have natural gas available at your house then a heat pump is probably not the most economical choice. Here in New Hampshire though NG is not available at many homes and a cold weather heat pump ends up being the cheapest option versus heating oil or propane.
akira2501 3y ago
So, this is based on the assumption that electricity coming into the home is 100% efficient and none of the systems inefficiencies in power generation or delivery need to be accounted for, the way they are in fossil fuels? That doesn't seem particularly useful.
- francisofascii 3y ago
  Right, this measure is more for consumers and does not take into account generation or delivery. It is especially useful when comparing heat pumps to electric resistance heat, which is often the backup heat source. If the COP falls below one, you switch to resistance heat. But this article is saying heat pumps built today can operate well over 1 at very low temps.

lazide 3y ago

Because it’s delusion. BTUs from hydrocarbon gases (and hydrocarbons in general) are phenomenal, and Natural gas is generally more of a waste product from oil extraction than anything, so is dirt cheap. The equipment required to use them (a typical furnace or boiler) is also cheap, low maintenance, well understood, and widely deployed everywhere. Most cold climates use fossil fuel heating. Heat pumps aren’t terrible, and are vastly more efficient than resistive heat for heating. If the only energy source is cheap and electric, it’s an easy win. But for areas already widely using fossil fuel heating (such as Germany), switching to heat pumps will increase electrical demand by at least an order of magnitude - best case - and since peak heating demand tends to happen when it’s winter, better have adequate storage too. Germany also has very expensive electricity, so it will dramatically increase costs unless extensive amounts of insulation are also done, increasing capex. So, if we look at price, and especially if we include capex, it’s only competitive in niche contexts or if we expect fossil fuel costs to be immediately and rapidly increased 4-5x. Even then, if done widely it will break a lot of things unless there is a lot of grid upgrades too. Increasing capex. It’s why Germany is struggling to switch off. They’re not the only ones.

no_wizard 3y ago
German energy policy baffles me. The were once the leader in nuclear energy. They really should have kept that lead, and built more nuclear plants and aggressively switched to electric first solutions such as heat pumps, EVs etc. Instead, they are winding down their nuclear power plants, and increasing their reliance on fossil fuels in the near to mid term, at the very least, which means issues like this will plague them for some time. No idea why they didn't pursue more energy independence when they had the chance
- lazide 3y ago
  It boils down to feeling good about helping the planet, without doing the math or recognizing the hard realities IMO. When the policy was started, the USSR had fallen, the world was on the upswing, etc. etc. optimism, enthusiasm, etc. These issues were all called out at the time.
- 3y ago

deleted 3y ago

[deleted]