John Rumm wrote:
The prices for energy they quoted also look unrealistic (they did have
the ratio of lekky to gas price about right - but numbers that looked
like they were a decade old - so that would have made the comparisons
come out much "closer" than in reality).

There's lots of stuff about heat pumps around that's about a decade old
(including the report posted in this thread) - things have moved on, so they
should be read with large pinches of salt.

They were also keen to compare against coal fired and resistive electric
heating, but seemed to leave out comparisons to gas / oil.

(I would be surprised if there are that many places with coal fired CH
in the UK!)

Coal fires yes (listed old houses etc), but not centrally heated...

Even the assumption that "renewable" energy is low carbon is a bit of a
stretch for the UK, where the best load factor for wind is under 50%,
and under 25% for solar in the summer (4% in the winter!), so more the
half the time the energy shortfall is being made up by fossil
alternatives generally.

I did the numbers and a heat pump running from electricity generated by a
CCGT still works out less CO2 per kwh heat than burning oil. It was a bit
more than burning gas directly, although that depends somewhat on your COP.

Theo