roof-mounted solar water-heating panels. (Summer solar heat is stored in
the ground for subsequent use in winter by Drake Landing Solar Com-
munity in Canada [www.dlsc.ca].) Alternatively, we should expect to need
to use some air-source heat pumps too, and then we’ll be able to get all
the heat we want – as long as we have the electricity to pump it. In the
UK, air temperatures don’t go very far below freezing, so concerns about
poor winter-time performance of air-source pumps, which might apply in
North America and Scandanavia, probably do not apply in Britain.
My conclusion: can we reduce the energy we consume for heating?
Yes. Can we get off fossil fuels at the same time? Yes. Not forgetting
the low-hanging fruit – building-insulation and thermostat shenanigans
– we should replace all our fossil-fuel heaters with electric-powered heat
pumps; we can reduce the energy required to 25% of today’s levels. Of
course this plan for electrification would require more electricity. But even
if the extra electricity came from gas-fired power stations, that would still
be a much better way to get heating than what we do today, simply setting
fire to the gas. Heat pumps are future-proof, allowing us to heat buildings
efficiently with electricity from any source.
Nay-sayers object that the coefficient of performance of air-source heat
pumps is lousy – just 2 or 3. But their information is out of date. If
we are careful to buy top-of-the-line heat pumps, we can do much better.
The Japanese government legislated a decade-long efficiency drive that has
greatly improved the performance of air-conditioners; thanks to this drive,
there are now air-source heat pumps with a coefficient of performance of
4.9; these heat pumps can make hot water as well as hot air.
Another objection to heat pumps is “oh, we can’t approve of people
fitting efficient air-source heaters, because they might use them for air-
conditioning in the summer.” Come on – I hate gratuitous air-conditioning
as much as anyone, but these heat pumps are four times more efficient
than any other winter heating method! Show me a better choice. Wood
pellets? Sure, a few wood-scavengers can burn wood. But there is not
enough wood for everyone to do so. For forest-dwellers, there’s wood. For
everyone else, there’s heat pumps.
142Loft and cavity insulation reduces heat loss in a typical old house by about a
quarter. Eden and Bending (1985).
143The average internal temperature in British houses in 1970 was 13 °C! Source:
Dept. of Trade and Industry (2002a, para 3.11)
145Britain is rather backward when it comes to district heating and combined
heat and power. The rejected heat from UK power stations could meet the