Propane-powered heat pumps are greener

ELECTRICITY CANEU be made from the sun, the wind or the atom rather than by burning fossil fuels. Cars, buses and perhaps even lorries can be powered by batteries rather than petrol or diesel. But other parts of the economy are trickier to decarbonise. One such awkward chunk is the heating, in homes and business, of air and water. In the , where much of this is done by burning oil or natural gas, commercial and residential heating accounts for about 12% of the bloc’s greenhouse-gas emissions (see chart).