3 ms·

Because it isn't mildly long. It's either very long or infinite, anywhere where gas is ~ 1/3 the cost of electricity per kWh. COP of 3 at a 3:1 price ratio for

Because it isn't mildly long. It's either very long or infinite, anywhere where gas is ~ 1/3 the cost of electricity per kWh. COP of 3 at a 3:1 price ratio for electricity to gas = 1. Which itself makes sense if you use gas as the RELIABLE source of kWh. You need to burn ~ 3kWh of primary energy in gas to deliver 1 kWh to the household, so 3:1 makes sense, and the RELIABLE source of kWh is the price setter because a failure of the grid is literally an existential crisis, something the "agile" private sector companies aren't liable for. An auxiliary annoyance in the UK is that reversible pumps aren't renewable for government grants. This is ostensibly to discourage aircon, but rather silly, since there are few easier green power problems today than "satisfy a demand that is almost perfectly correlated with high insolation". FYI as a type the largest suppliers are gas, solar, then nuclear - of which nearly half is being pulled from France, an amount that for some reason isn't always counted by some people.

yathern 3y ago
> you need to burn ~3kWh of primary energy in gas to deliver 1 kWh to the household Is that so? I thought electric generation from natural gas was at least 80% efficient - and transmission losses maybe can pull that as far down as 66% - but not down to 1/3.
- voisin 3y ago
  I think they are referring to the COP of a heat pump as at least 3, whereas natural gas appliances by definition must be below 1.
ZeroGravitas 3y ago
In many EU countries that cost difference is a policy failure: > Italy, Spain, the United Kingdom, Belgium and Germany. All five countries overtax electricity — in three cases by more than 200% — and undertax oil and fossil gas while not taxing wood use at all. Only in Italy is the tax rate on heating oil close to the value of the environmental costs caused by its use. https://www.raponline.org/knowledge-center/aligning-heating-energy-taxes-levies-europe-climate-goals/ https://www.raponline.org/knowledge-center/aligning-heating-... But going from first principles Renewable Energy Without the Hot Air could run the numbers back when it was written in 2008 and show this was a good move: https://www.withouthotair.com/c21/page_151.shtml https://www.withouthotair.com/c21/page_151.shtml > Let me spell this out. Heat pumps are superior in efficiency to condensing boilers, even if the heat pumps are powered by electricity from a power station burning natural gas.

yathern 3y ago

> you need to burn ~3kWh of primary energy in gas to deliver 1 kWh to the household Is that so? I thought electric generation from natural gas was at least 80% efficient - and transmission losses maybe can pull that as far down as 66% - but not down to 1/3.

voisin 3y ago
I think they are referring to the COP of a heat pump as at least 3, whereas natural gas appliances by definition must be below 1.

ZeroGravitas 3y ago

In many EU countries that cost difference is a policy failure: > Italy, Spain, the United Kingdom, Belgium and Germany. All five countries overtax electricity — in three cases by more than 200% — and undertax oil and fossil gas while not taxing wood use at all. Only in Italy is the tax rate on heating oil close to the value of the environmental costs caused by its use. https://www.raponline.org/knowledge-center/aligning-heating-energy-taxes-levies-europe-climate-goals/ https://www.raponline.org/knowledge-center/aligning-heating-... But going from first principles Renewable Energy Without the Hot Air could run the numbers back when it was written in 2008 and show this was a good move: https://www.withouthotair.com/c21/page_151.shtml https://www.withouthotair.com/c21/page_151.shtml > Let me spell this out. Heat pumps are superior in efficiency to condensing boilers, even if the heat pumps are powered by electricity from a power station burning natural gas.