heating needs of the entire country (Wood, 1985). In Denmark in 1985, district
heating systems supplied 42% of space heating, with heat being transmitted
20 km or more in hot pressurized water. In West Germany in 1985,
4 million dwellings received 7 kW per dwelling from district heating. Two
thirds of the heat supplied was from power stations. In Vasteras, Sweden in
1985, 98% of the city’s heat was supplied from power stations.

147Heat pumps are roughly four times as efficient as a standard electrical barfire.
See www.gshp.org.uk.
Some heat pumps available in the UK already have a coefficient of peformance
bigger than 4.0 [yok2nw]. Indeed there is a government subsidy for
water-source heat pumps that applies only to pumps with a coefficient of
peformance better than 4.4 [2dtx8z].
Commercial ground-source heat pumps are available with a coefficient of
performance of 5.4 for cooling and 4.9 for heating [2fd8ar].

153Air-source heat pumps with a coefficient of performance of 4.9... According
to HPTCJ (2007), heat pumps with a coefficient of performance of 6.6 have
been available in Japan since 2006. The performance of heat pumps in Japan
improved from 3 to 6 within a decade thanks to government regulations.
HPTCJ (2007) describe an air-source-heat-pump water-heater called Eco Cute
with a coefficient of performance of 4.9. The Eco Cute came on the market
in 2001. www.ecosystem-japan.com.

Further reading on heat pumps: European Heat Pump Network

ehpn.fiz-karlsruhe.de/en/,
www.kensaengineering.com,
www.heatking.co.uk,
www.iceenergy.co.uk.

Figure 21.14. Advertisement from the Mayor of London’s “DIY planet repairs” campaign of 2007. The text reads “Turn down. If every London household turned down their thermostat by one degree, we could save 837 000 tons of CO2 and £110m per year.” [london.gov.uk/diy] Expressed in savings per person, that’s 0.12 t CO2 per year per person. That’s about 1% of one person’s total (11 t), so this is good advice. Well done, Ken!