In some markets, some of the time, biomass, geothermal, landfill gas and waste-to-energy can compete on price with carbon-based fuels.

ECONOMIST: When virtue pays a premium | The

In many countries power from landfill gas or waste-to-energy plants (like the one at Spittelau, outside Vienna, illustrated above) attracts subsidies of one kind or another because it saves emissions.

ECONOMIST: The waste business smells of money

Waste-to-energy and landfill-gas projects are likely to benefit most from green pricing, at least at first, because their costs are already close to those of conventional power producers.

ECONOMIST: When virtue pays a premium | The

Chris Wick, from the Environment Agency, said landfill sites generated gas when waste broke down but 2012 had been exceptionally wet and it was believed heavy rain had increased the gas produced.

BBC: Landfill site (generic)

They point out that biodegradable waste in a landfill releases methane, a potent greenhouse gas, while incinerators which can also generate electricity from combusting rubbish emit mainly less-damaging carbon dioxide.

ECONOMIST: Tough landfill targets prompt a return to flaming rubbish