Tom Freeman, Holyrood
If you live in Copenhagen or one of the Danish capital’s surrounding towns, it is extremely unlikely you will have a boiler stowed away under the stairs to heat your home.
Instead, pipes come directly into your house from a heating network which serves the entire area, as part of one of the world’s largest district heating systems.
In fact, your home is being warmed by waste heat from a power plant or waste incinerator, just like 97 per cent of buildings in the district.
Actually, Copenhagen’s current mayor, Frank Jensen, says his biggest headache when it comes to energy use is the growth in trendy wood-burning stoves, which still pollute the environment.