Can reusing waste heat from cryptocurrency mining offset your carbon footprint? Apparently, yes — and everyone wins.
For someone who cares about climate change, Matt Carlsson I had what seemed like a dream job: teaching clients how to decarbonize buildings.
But I was frustrated. It could give customers the tools to improve energy efficiency and phase out fossil fuels, but if they couldn’t easily turn its guidance into cost savingsthey simply ignored him.
“The majority of these people will not act, because there will be no economic justification”, he realized.
Carlsson decided he needed to find a job where he could defend energy efficiency in economic termswhich took him to a surprising place: bitcoins.
A Bitcoin mining releases a huge amount of heat. The term “mining” in this context refers to the intensive computational process in energy through which bitcoin transactions are verified, explains .
In a typical transaction, a computer tries to solve which is essentially a very complex mathematical problem. If it can do so before any of the other “miners” working on the problem around the world, the miner is rewarded with bitcoins.
This process consumes a lot of energy; Overall, bitcoin mining accounted for about 0.5% of global electricity consumption in 2024.
The more complex the task at hand, the more electricity is needed — and the more heat is created. Essentially, as long as it is profitable to mine bitcoinwill continue to produce a lot of extra heat as a byproduct.
The question becomes: Can this heat be used in a beneficial way?
This is where Carlsson comes in, who is now helping to heat the houses of 80,000 people in Finland with waste heat from local miners of cryptocurrencies, as part of a project managed by his new employer, the bitcoin mining company.
The process is simples: water used to cool computersmining passes through MARA minerswhich are stored in metal units in the center of the localities, cooling them before leaving at a tscalding temperature of 50 to 78°C.
From there, the water is pumped underground through the systems of urban heating existing in the city, drastically reducing the need for traditional boilers.
As a result, since its first project came into operation in 2024, two MARA “bitcoin neighborhoods” avoided gas emissions greenhouse effect equivalent to those produced by 700 common dwellings.
Carlsson thinks that this model could be expanded for cities and buildings around the world, and you’re not the only one thinking so. Joint Bitcoin Mining and Heating Operations are popping up all over Finland — an ideal location, due to its cool climate and existing district heating systems that businesses can easily connect to.
The “Genesis” project, for example, is sending waste heat from bitcoin mining to be used in an industrial area of the Nordic country, as well as some nearby houses.
The global bitcoin mining infrastructure company manages six facilities that connect miners to district heating systems elsewhere in Finland, with more in the pipeline.
“It’s a business, after all“, it says Alen Makhmetovco-founder of Hashlabs. “I just want to make our business much more sustainable, robust and long-term.”
Although there is also a climate argument in favor of the operation, Makhmetov refers to “sustainable” in an economic sensebecause Hashlabs is now protected against a collapse in the price of bitcoin: If you lose cryptocurrency income, you will still have revenue from your heating services.
Os heating customers are also protected: Hashlabs has promised to continue producing heat even if the value of bitcoin makes mining it unprofitable.
“It was really a obvious decision“, it says Adam Swickdirector of strategy at MARA. In effect, the company can obtain two sources of income: earn bitcoins through mining, obviously, but also receives a fee of municipalities for the supply of heat — and also receive free water needed to cool your miners.
Residents of the two locations where MARA operates, the Satakunta region and the city of Seinäjoki, can not even notice that something has changedsince they are receiving heat from the same pipes they always have.
“That’s kind of the goal, that no one is affected“, says Swick. MARA has taken on all equipment costs and is providing heat at a lower price compared to electric heating companies.
From MARA’s perspective, it’s also better for the climate. District heating systems in Finland are mostly powered by burning biomasssuch as wood shavings.
Although biomass is considered renewable by some, including the European Union, it is still emits carbon when burned.
By reducing the amount of biomass and peat that municipalities need to use, MARA calculates that it has eliminated almost 5,000 tons of gas emissions greenhouse effect over the year and a half in which its municipalities were operating.
Of course, it’s easy to argue that the only thing better than efficiently utilizing bitcoin’s waste heat is not mining bitcoin at all. But, in a world where this will no longer happen, it is better to take advantage of the extra heat generated by mining — with benefits for everyone.
