With the debate over crypto mining’s energy use increasingly involving renewable sources, an increasing number of UK farmers are turning to a surprising reservoir of power – cow waste, aka dung – to generate electricity for carbon-neutral crypto mining operations, thus diversifying and increasing their revenues.

Currently, a portion of the country’s farmers generate power from manure and sell it to the National Grid, the business that controls England and Wales’ high-voltage energy transmission network. According to the UK newspaper Metro, selling renewable energy to the National Grid may earn farmers roughly GBP 0.07 (USD 0.1) per kilowatt, whereas operating a crypto rig may make GBP 40 (USD 56.4) per day and over USD 21,000 per year.

In accordance with the trend, Easy Crypto Hunter, a UK startup that specialized in crypto mining hardware, has seen a significant spike in demand from farmers trying to diversify and enhance their profits.

The startup operates its own gear and mines carbon-neutral cryptocurrency using dung — more specifically, methane-to-electricity. According to Riddett, they and their clients mine cryptocurrencies such as ethereum (ETH), but not bitcoin (BTC), “because it’s not as energy efficient as other coins and it’s not as lucrative.”