In 2011, Redditch council in England proposed using waste heat from a nearby crematorium to warm the local swimming pool. The idea triggered public outrage and international headlines, but the system was eventually installed, won a green award and has supplied heat to the pool since 2013.
From controversy to operation
Union officials initially described the plan as “sick” and “an insult to the residents.” The union spokesperson’s comments were attributed to Unison, which said they were not, and are not, the union’s official position. The proposal nevertheless attracted international headlines.
“All you’re basically doing is heating up a radiator and pumping that heat into tubes,” says Guy Revans, a councillor for Redditch and Bromsgrove councils, south of Birmingham. “But death is always an emotional subject, isn’t it?”
After the initial coverage subsided, the project won a green award. The crematorium has heated Redditch’s swimming pool since 2013.
How the heat-recovery system works
About 1,200 cremations take place in Redditch each year. The crematorium has two gas-fired ovens. A heat exchanger captures heat from their exhaust gases during the process used to remove vaporised mercury from dental fillings. The remaining gas is then vented into the atmosphere.
Heat recovery is already a common feature of many crematoriums. In effect, the excess heat is captured as part of the normal process; the question is whether it will be used or wasted. In Redditch, the heat exchanger transfers the energy to a water loop running 200 metres underground. The loop carries the heat to a second heat exchanger, which supplies the swimming pool.
Large bodies of water can “act as heat sinks,” Revans says. “When you add heat during the day, it retains that heat for a significant amount of time.” The recreation centre also has a gas-fired boiler that can provide additional heat when necessary. Overall, the system has saved the council tens of thousands of pounds a year in fuel costs.
A potential source of lower-carbon heat
Although such systems are extremely rare in North America, crematoriums in Europe have supplied heat for many years. The total amount of heat available from crematoriums is small, but recovering it could reduce the carbon intensity of funerals as communities look for ways to lessen their environmental impact.
Similar projects have since appeared elsewhere. A school under construction in Aberdeen, Scotland, is expected to receive additional heat from the city’s crematorium. Crematoriums also already use recovered waste heat to warm their own buildings.
Source: www.wired.com
