Cardiff, Wales, may see heat piped underground for use in homes and businesses from burning garbage, according toCogeneration & On-Site Power Production magazine. Under the proposal, 172,000 tonnes (189,597.55 U.S. tons) of household garbage would be burned in an incinerator. The Cardiff District Heating Network would provide cheaper, greener heating to buildings in the vicinity by replacing conventional gas heating systems.

Waste heat from the incinerator would be captured and piped underground to the city’s district heating plant. The incinerator could deliver up to 20 MW of heat, which will be transported in the form of hot water. District schemes such as these, the magazine reported, provide a secure supply of heat and hot water to homes and buildings through a network of well-insulated underground pipe.