Nuclear heat keeps people warm in many countries. Why not ours?
Welcome to our weekly newsletter where we highlight environmental trends and solutions that are moving us to a more sustainable world.
Hi, it’s Emily. Some time ago, Michael Wiggin at the Boltzmann Institute spoke to me about the idea of using heat from nuclear power plants for district energy. I was intrigued, and decided to look into the idea.
This week:
- Nuclear heat keeps people warm in many countries. Why not ours?
- The Big Picture: Who’s got big solar potential?
- Carney leans on private money, alternative approaches in nature strategy. Will it work?
Nuclear heat keeps people warm in many countries. Why not ours?
About 400,000 people in homes in three cities in northern China stayed warm and cozy this winter, thanks to heat piped from their local nuclear power plant.
The Haiyang nuclear plant feeds into a district heating network called Warm Nuclear No.1, which has been expanding since 2019 and also serves the neighbouring cities of Rushong and Weihai. It’s now preparing to extend to Qingdao City, 130 km from Haiyang.
As of December 2025, heat from the nuclear power plant had displaced 1.3 million tonnes of coal and cut CO2 emissions by 2.3 million tonnes, improving winter air quality in the cities it heated, the International Atomic Energy Agency reported.
WATCH | Nuclear-derived district heating used in northern China:
While this project pushes the limits of the technology and is the biggest of its kind in the world, it’s not a new idea – district heating, where entire neighbourhoods are heated using a network of pipes carrying heat from one or more heat sources, has made use of heat from nuclear plants for more than half a century.
In Sweden, the Agesta reactor was used for district heating in a suburb of Stockholm for a decade starting in 1963.
Since then, the technology has spread to many other countries, including Bulgaria, Czech Republic, Hungary, Romania, Slovakia, Ukraine and Switzerland, where the Beznau nuclear power plant has supplied up to 99 kilometres of district heating network pipes since 1983.
“It’s gaining a lot more interest,” said Francesco Ganda, technical lead for non-electric applications at the IAEA. He said that’s especially the case in places that already have district heating networks and don’t need to invest in building a new one, which can be costly.
Using a reactor to co-generate heat will reduce its electricity production a little, Ganda said, but the tradeoff is five times that energy in the form of heat. “It’s a very efficient process.”
He added that more than 60 reactors around the world are capable of supplying both electricity and heat, and a number of countries are expanding their use of nuclear for district heating, including China and the Czech Republic.
But what about Canada, where nuclear power plants supply 14 per cent of the country’s electricity and more than half the electricity in Ontario?
1st Canadian project faces challenges
While heat from Canadian nuclear power plants was harnessed for industrial use in the past (to make heavy water), it hasn’t yet been used in district heating.
That looked like it was about to change with the announcement a year ago of $1.4 million in government funding for a project in Hamilton, Ont., that would use heat from McMaster University’s research reactor to heat the AN Bourns Building next door.
Jim Cotton, a professor of mechanical engineering at McMaster who researches waste heat recovery, said it’s an idea McMaster has been discussing for decades (the reactor is 65 years old). His own studies suggest McMaster’s reactor generates enough heat to decarbonize up to half the campus.
Unfortunately, he said, more detailed design studies showed the project would cost more than anticipated — mostly due to the cost of building a compatible district heating system.
Things got even worse after the federal consumer carbon tax was cancelled, reducing the savings from displacing fossil fuels that were used to justify the costs.
That means the project is off for now.
But Cotton hasn’t given up – he’s looking at other options, such as building a new reactor that can make use of the campus’s existing district heating system, which is designed for hotter water than the research reactor can produce.
And he says Canadians could potentially tap into heat from other nuclear reactors in Ontario.
“I think there is a big opportunity,” he said, especially given that some new reactors are still in the design stage, when it’s easier to incorporate this technology.
It’s an opportunity that spurred discussion at two Canadian nuclear industry conferences last year, led by the Boltzmann Institute, a think-tank focused on decarbonized heating.
The institute estimates that making a nuclear power plant that’s district heating “ready” during its design and construction adds less than 0.2 per cent to its cost, while promising to provide an extra revenue stream, making the plant more valuable to society, and reducing spikes in electricity demand from heating (and therefore the price of electricity).
Michael Wiggin, a director at the institute, said unfortunately, Canada currently has a “chicken and egg situation,” where utilities won’t build or expand district heating networks unless there’s a cheap, available source of heat, and nuclear plants aren’t motivated to make their heat available unless there’s a district heating network to buy it.
He thinks that means governments need to lead by supporting the idea: “That’s where the challenge is right now.”
— Emily Chung
Old issues of What on Earth? are here. The CBC News climate page is here.
Check out our podcast and radio show. In our latest episode: Canada faces a climate conundrum when it comes to the military. To maintain northern sovereignty, defence needs to adapt quickly to the warming Arctic. But even before the recent boost in investment, the military was already the single largest emitter of greenhouse gases in the federal government. So how can Canada defend the North and stick to its climate goals at the same time? Then, we hear about Canada’s new $3.8 billion investment plan to protect nature.
What On Earth24:43Does a military upgrade mean a climate downgrade?
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Reader feedback
We received a few questions about Nick Logan’s article last week about burying burnt trees after wildfires to prevent their remaining CO2 from getting into the atmosphere and causing more climate change. We’re still looking into them and hope to print some answers next week.
A couple of weeks ago, Nicole Mortillaro wrote about the millions of birds that are killed each year by people’s cats. We had plenty of feedback, with a few readers, like Dave Garson, asking if putting a bell on a cat would prevent them from successfully hunting birds. While it can certainly help, bells aren’t 100 per cent effective, as cats learn how to suppress the sound by staying extremely still (Nicole witnessed this herself with the cat mentioned in the story). As for letting them out at night, which reader Debbie Hunka mentioned, that also isn’t great as they hunt birds in their nests, as Ryan Norris noted in his research.
Write us at whatonearth@cbc.ca (and send photos there too!)
The Big Picture: Who’s got big solar potential?
This map shows how much power solar panels in different parts of the world could potentially produce in a year – and you can see that one of the reddest areas is the continent of Africa.
According to the International Energy Agency, Africa has 60 per cent of the world’s best solar resources, since most of it is near the equator, with little dust and cloud cover.
Meanwhile, there’s been a push to connect the 600 million Africans with no access to electricity by 2030 to align with the UN’s goal of universal access.
Amos Wemanya, senior climate advisor at Power Shift Africa, an African think-tank that promotes renewable energy, said many African countries have traditionally relied on imported fossil fuels with volatile prices. Solar, he said, “provides the opportunity for energy sovereignty.”
It’s starting to happen. Solar achieved record growth in Africa in 2025, with a 54 per cent increase in solar installations, the Global Solar Council reports. That’s happening along two tracks: rooftop systems funded by individual homeowners and utility-scale plants that connect to national grids, which are considered the cheapest option to provide electricity access to nearly half the African population who need it.
We took a closer look at projects from two Canadian companies that are building utility-scale solar in Africa – and what they say about the challenges and opportunities there.
— Emily Chung
Hot and bothered: Provocative ideas from around the web
Carney leans on private money, alternative approaches in nature strategy. Will it work?
Canada has only four years left to reach its ambitious goals to protect 30 per cent of its lands and oceans by 2030. That’s about double what’s protected right now, which means the government is trying to speed up the work.
Prime Minister Mark Carney’s new nature strategy, released on Tuesday, leans heavily on two approaches that are raising some eyebrows: efforts to get businesses and investors to put private funding into conservation, and officially recognizing what are known as “other effective area-based conservation measures,” or OECM, which are areas that are protected by local communities and private groups.
The new approaches could provide an important boost to conservation in Canada and reduce the burden on Ottawa to do the work alone, but experts say if it’s not done correctly, these other-conserved areas may end up existing on paper but not providing the level of protection necessary for ecosystems to thrive.
What are other-conserved areas?
OECMs are used mainly by smaller municipal governments or Indigenous communities to get recognition for projects that don’t fit neatly into the definition of, say, a provincial park or nature reserve.
Examples include projects to protect the water supply for cities or efforts to conserve hunting and fishing grounds for Indigenous communities, which may not have nature protection as a primary purpose, but achieve those protections anyway.
Michael Bissonnette, staff lawyer at West Coast Environmental Law, has worked on OECMs established in marine areas, and said they have been quite successful especially when paired with Indigenous-led conservation areas nearby.
“But there’s a wide gamut of what can be contemplated as OECMs. Some of them are fantastic and then there’s some that there’s been a lot of criticism about,” he said.
The federal government maintains a database of OECMs, also known as other-conserved areas, but Carney’s announcement was the first time they’re being officially counted toward meeting Canada’s conservation targets. The nature strategy calls for at least eight per cent of lands to be protected under other-conserved measures.
Megan Lafferty, manager of land protection measures at the Nature Conservancy of Canada, works with municipalities and private groups on other-conserved areas. She says Canada has been on the forefront of developing tools to assess how effective OECMs are and to make sure they actually protect nature in a comparable way to parks or other conserved areas.
OECMs are not a “consolation prize” instead of establishing some kind of park, Lafferty said, but rather “what is fit-for-purpose on the landscape.”
OECMs allow local communities to get recognition for the actual outcomes of their conservation work, Lafferty said.
But critics of the approach say that OECMs have been shown to allow industrial activities, like logging, especially in B.C. where they are widely used. A 2022 report from two environmental groups said that other-conserved areas were falsely inflating B.C.’s progress to its nature protection goals, because most of these areas were still open to logging.
Lucero González, Wilderness Committee, says that OECMs were never meant to form such a large part of Canada’s target. She also raised concerns about how they are tracked, long-term, to ensure they continue giving the environmental benefits they’re supposed to.
“We do fear that they are going to be used to inflate a number and not to reach the goal of halting the biodiversity crisis,” González said.
“What we’ve seen right now is that, no, they have not been able to be used properly, both in having standards when they get designated and in the future for tracking their progress.”
In a statement, Environment and Climate Change Canada said, “Mining, logging, and other forms of resource extraction are not compatible with OECM and would not normally be included in the boundaries.”
What’s the role of private money in the new strategy?
Carney also announced a new task force on natural capital accounting and nature financing to account for the economic value of nature and to mobilize private finance and investment into protected nature.
Details are scarce right now on how exactly the government will do this, but some models for increasing philanthropic contributions for nature have been used in Canada, for example to protect part of the Great Bear Sea off the coast of B.C.
“I think the government would like to see more of those kinds. Models of matching of private philanthropic funding with government funding,” Bissonnette said.
But he said with the 2030 deadline fast approaching, he is concerned that there isn’t a lot of detail available about how the government will raise that private funding.
González was critical about the overall message Carney’s emphasis on private money sends on nature.
Focusing on private capital, she said, means that “nature protection is not in the hands of the people that are being affected by extractivism and by industrial development, but in the hands of the people running those extractive industries.”
“It really shifts the focus on and and takes power away from those that are experiencing climate change and biodiversity loss on the ground and gives it all to those that have benefited from it,” González said.
She said that the government needs to refocus on the purpose of the nature goal — to combat the biodiversity crisis and mass extinction of species being seen in Canada and across the world — rather than to reach numerical goals.
— Inayat Singh
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Editors: Emily Chung and Hannah Hoag | Logo design: Sködt McNalty
