A pair of Russian builders may have stumbled on an environmentally friendly way to utilise the energy produced by Bitcoin mining.Ilya Frolov and Dmitry Tolmachyov, from Irkutsk in Siberia – which experiences average temperatures of between -6ºC and -18ºC from November to March – have built a small cottage in the town and installed two bitcoin miners to warm up a liquid which is then transported through a heating system installed beneath the floor. Because Bitcoin mining – which validates the transactions made using the cryptocurrency – rewards those who invest in the technology with a small amount of the digital money, it is thought that the cottage is being heated at a profit of $430 per month, or over $5,000 per year. As the builders revealed, the environment was a big factor in their plans: “People who mine cryptocurrencies use big miners. And they just heat the atmosphere,” said Dmitry Tolmachyov in a Quartz video, embedded below. “And we say, ‘No, the environment! We shouldn’t heat the atmosphere. We have a nine-month long heating season. We should heat our homes. The miners should not be concentrated in one place. They should be in various places, in private homes. The technology allows it nowadays.”Bitcoin mining produces large amounts of heat and there has been a wide discussion in recent years over how best to harvest the heat produced in large data centres. However, if Frolov and Tolmachyov's idea is picked up by a wider audience, we could soon see Bitcoin mining become an alternative – and highly lucrative - energy source. The blockchain is estimated to consume a similar level of energy to the country of Denmark by 2020, so the world will be looking for more examples like the Russian builders.