Waste heat from sewage works and data centres may keep many people warm in a future low-carbon world.
The heat from incineration and industries could also be captured and piped to hospitals, offices, schools, and homes.
Warmth may also be sucked out the sea from old coal mines – and the rivers – using heat pumps that work like fridges in reverse.
A sixth of heat required for buildings could come from so-called district heat networks, authorities said.
A network of pipes is laid under city roads to convey warm water produced at a centralised location by low-carbon technology.
It’s part of a heating revolution being driven by the United Kingdom’s commitment to combat climate change by ending the wastage of gas for heat.
For now, debate has focused on the struggle between hydrogen heating for people’s homes or individual air source heat pumps.
“It’s crucial to get district heating into the debate. It’s so appealing in densely populated cities,” Chris Stark from the federal advisory Climate Change Committee told USA Today.
“And it’s a great solution for conservation areas because it provides a low-carbon option for housing where it would be expensive or difficult to upgrade the fabric of the building itself.”
District heating networks are common in Scandinavia, where many are powered by municipal waste from people’s homes or scrap from the timber industry.
Mr Stark said each city and town should start zoning and planning its own heat decarbonisation. He presumes $20 billion to be invested into district heating by 2030.
Abandoned coal mines might offer a valuable source of heat, he says.
The CCC is encouraging the government in its impending Heat and Buildings Strategy to give multi-year funding for district schemes.
At least 18% of homes will be warmed by district heat in the CCC’s Strategy by 2050.
