[harg]

You get more heat out of using a given quantity of gas to generate electricity which is used to to power a heat pump than you do by burning the gas directly for heat, even when considering generation and transmission losses etc.

Given that even during a time of low output from renewables we still only rely on 53% gas for electricity generation it's still much more beneficial environmentally to use a heat pump.

The monetary cost is another story though, and I agree we do need to work on weaning ourselves off gas.

[StillBored]

In areas with moderate outdoor temperatures. Anywhere that the heatpump is going through defrost cycles, that statement is likely false because the COP is likely 1 or less when that starts happening.

Then on the generation side, its worse if the NG generation isn't a modern combined cycle plant. which also tends to nix places with a lot of renewable generation because the NG plants are just peaker gas turbines with much lower efficiency than plants designed for continuous use. So, its all situational, but at the same time if one has the choice for cheap NG using that as a second stage and setting the crossover heatpump temperature at the cost/BTU intersection between the heatpump and NG second stage is a rough approximation of the enviromental costs as well as the actual cost.

[triceratops]

> In areas with moderate outdoor temperatures. Anywhere that the heatpump is going through defrost cycles, that statement is likely false because the COP is likely 1 or less when that starts happening.

Modern heat pumps have a COP close to 2 at 5F/-15C while still delivering 50k+ BTUs. Here's one example: https://ashp.neep.org/#!/product/68628/7/25000/95/7500/0///0

[broken-kebab]

Can you elaborate on the statement in the first para? Is it a guess, calculation, or there are real-world data?

[Tostino]

A heat pump can be well over 100% efficient based on the energy input for equivalent resistive / chemical heating. E.g. your heat pump could use 100w of electricity to move 400w worth of heat (if generated resistively) from the outside to inside.

There have been multiple studies done that show that current generation heat pumps are quite a bit more efficient for a given volume of gas to burn it in an electrical generation plant and use a heat pump than it is to burn it in the house / building.