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In 2011, the Redditch Borough Council in England launched an initiative that had largely gone unnoticed across the United Kingdom. The council staff announced plans to heat the local swimming pool using excess heat from a nearby crematorium. This unconventional proposal sparked widespread public controversy, capturing international headlines, with a union leader branding it as “disgusting and an insult to local residents.” However, a spokesperson from Unison clarified that this view did not reflect the official stance of the organisation.
“Essentially, it’s just heating a radiator and channeling the warmth through a pipe,” explains Guy Revans from the councils of Redditch and Bromsgrove, located south of Birmingham. “But death is always a sensitive subject, isn’t it?”
The Evolution of a Controversial Project
Over time, the media frenzy surrounding the project subsided. The initiative not only won an environmental award but has been successfully heating the Redditch swimming pool since 2013. While this practice is relatively rare in the United States, many European countries have long been utilising heat from crematoria. Although the total amount of heat generated by crematoria is modest, harnessing this residual heat presents a viable opportunity to reduce the carbon footprint associated with funeral practices.
In Redditch, approximately 1,200 cremations occur annually. A heat exchanger captures heat from the combustion gases emitted by the facility’s two gas furnaces, part of a process designed to eliminate vapourised mercury from dental fillings, before releasing the remaining gases into the atmosphere. This method is standard in numerous crematoria. The critical question arises: does it make sense to waste this heat, or should it be put to use? In Redditch, the heat exchanger links to an underground water circuit extending 200 metres, ultimately reaching another heat exchanger that supplies the swimming pool.
Fortunately, such a substantial body of water “acts as a heat reservoir,” Revans adds. “If heat is applied during the day, it retains warmth for a considerable duration.” The recreational centre is also equipped with gas boilers that can provide additional heat as needed. Collectively, this system has resulted in savings of tens of thousands of dollars annually in fuel costs for the council.
Similar Initiatives Gaining Traction
Recently, similar projects have emerged in various locations. A school currently under construction in Aberdeen, Scotland, will receive surplus heat from the city’s crematorium, which already utilises residual heat to warm its own facilities. “They were only utilising a tiny fraction of the available heat; the rest was lost to the atmosphere,” remarks Ian Davidson, Managing Director of Aberdeen Heat & Power, who confirms that the system has received all necessary building permits. The crematorium is set to provide just under 1 gigawatt-hour of heat per year, covering approximately half of the school’s total energy needs. A heat pump will supply the remainder, with the entire system expected to be fully operational by February 2027.
Some crematoria are going even further in their push for sustainability. The crematorium set to open in 2028 in Kangasala, Finland, will be integrated into the local district heating network, a system of pipes supplying hot water for heating to over 6,500 homes. This crematorium will be fully electric and partially powered by solar panels installed on its roof.
Innovative Solutions for a Sustainable Future
“It’s something special,” observes Timo Heikkilä, an energy consultant for Thenco Oy, who is involved in the project. “I am very glad to be part of this.” Winter temperatures in Kangasala can remain below zero degrees Celsius for extended periods. Finland is trending towards reducing natural gas usage for heating, explains Heikkilä. Previously, gas was available cheaply from neighbouring Russia, but the invasion of Ukraine and growing concerns about climate change have prompted Finland to seek alternatives. In some cases, this means harnessing waste heat from unconventional sources, such as crematoria.
“Finns,” notes Heikkilä, “are quite practical.” Ian Rudkin, who has managed several crematoria in the UK and is now on the board of the Cremation Society of Great Britain, shares that many crematoria are adopting a more environmentally friendly approach. Today, software can schedule the ignition of gas furnaces to coincide with funeral services, ensuring that energy is not wasted and that the furnaces only operate when necessary. Additionally, some crematoria store coffins for up to 72 hours, allowing multiple cremations to occur consecutively, which enhances efficiency.
Challenges in the U.S. and Beyond
“When we first implemented it, families seemed a bit surprised,” recalls Rudkin. However, they soon accepted the practice more readily, often commenting, “Dad always turned off the lights at home to save energy.” Nevertheless, Paul Seyler, Director of Strategy at Matthews Environmental Solutions, acknowledges that implementing heat recovery technology in U.S. crematoria poses greater challenges. Urban heating networks are scarce, and crematoria are often privately owned. This means that the investment required for heat exchangers and connecting piping can be significant.
“We are closely studying this issue because, when economic viability allows, we would like to offer a solution,” Seyler adds. After all, wasted heat is merely a squandered resource, he asserts. Aside from some small-scale experiments, Seyler has not encountered any fully operational systems in the U.S. that utilise heat from crematoria. The closest example is found in Canada, at a funeral complex in Sainte-Thérèse, Quebec. This 3,255-square-metre building features family rooms, a large chapel, a crematorium, and a kitchen, among other facilities. Heat exchangers installed just over a decade ago capture heat from the combustion gases of cremation and distribute it throughout the complex, even warming sidewalks to melt snow in winter.
The Environmental Impact of Heat Recovery
“The owner was initially hesitant, as they thought it might pose an ethical dilemma,” recall design engineers Martin Roy and Lianne Cockerton in an article about the project published in ASHRAE Journal. Today, visitors pass by an LED screen in the reception area that displays the building’s energy performance, partly based on the operation of the heat exchanger. While gas is still used to meet some of the building’s heating needs and for cremations, the new system is estimated to save 29 metric tonnes of greenhouse gas emissions annually.
Recovering heat from cremations represents an attempt to counteract the “devastating impact” that humanity has had on the environment, comments Hannah Rumble, an associate researcher at the Centre for Death and Society at the University of Bath. “I understand that this could be a reason for people to choose to be cremated at a specific crematorium.”
Perceptions and Preferences in Funeral Practices
Most crematoria contacted maintain that they do not emphasise heat recovery technology to families or mourners. However, a spokesperson from the Aberdeen Council indicates that they will conduct a public awareness campaign regarding the new system before it becomes operational to ensure transparency. Gaynor Doherty, an independent humanist celebrant for funerals and weddings in the UK, believes that utilising residual heat from crematoria is “sensible.” Nevertheless, she suggests that natural burial, where bodies are simply wrapped or placed in biodegradable coffins and allowed to decompose in the environment, may be preferable for many environmentally conscious individuals.
The carbon intensity of cremation varies from facility to facility but can hover around 250 kilograms of carbon per cremation when using gas. Recovering heat from the process offsets some of these emissions—one company claims a reduction of 100 kilograms—but not all. A study published in 2024 estimated that if all crematoria in the UK were to harness their residual heat, it would only cover 1% of the country’s total heating needs. While this may seem minimal, decarbonising heating is notoriously challenging, making any measure toward this goal potentially valuable.
Moreover, some individuals may find great significance in sharing the warmth from their cremation. In Finland, the fully electric crematorium in Kangasala may not generate as much heat as a gas one, but it will operate 24/7. It is more efficient to utilise electricity to gradually replenish the heat retained in the ceramic materials within the furnaces. The connection to the urban heating network means that once mourners return home after services at the new crematorium, a portion of the warmth they feel upon entering their homes may indeed come from the cremation of their loved ones.
Heikkilä reflects on the important questions that working on the project has raised for him. “I’ve thought about it, and when my time comes, I would like to be cremated and have my residual heat recycled,” he states. “It’s the most sensible thing to do. It’s the last favour one can do for the world.”
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