Bitcoin mining’s clean-energy share hits 59.4%, complicating case for ESG curbs
Cambridge data shows hydropower has overtaken gas as Bitcoin mining's top power source, even as electricity use rose 38% and emissions climbed 20%.
Hydropower has overtaken natural gas as the single largest source of electricity for Bitcoin mining, according to preliminary research from the Cambridge Centre for Alternative Finance (CCAF), a shift that could blunt one of the most durable regulatory arguments against proof-of-work networks. The findings, presented by CCAF’s Alexander Neumueller at the Energy Investors Forum in Dallas, come as the network’s overall electricity demand has risen sharply, complicating any simple narrative about Bitcoin’s environmental footprint.
Bitcoin mining’s annualised electricity consumption climbed 38%, from roughly 138 terawatt-hours in June 2024 to about 190 terawatt-hours in December 2025, crypto.news reported, citing the Cambridge data. Over the same period, low-carbon energy sources rose to 59.4% of the reported mining mix, up from 52.4% in CCAF’s previous report published in April 2025, according to Crypto Briefing.
Emissions rise, but more slowly than power demand
The decoupling of energy consumption from emissions growth is the most consequential figure for policymakers scrutinising the sector. While electricity demand jumped 38%, total estimated greenhouse-gas emissions from mining rose by only about 20%, from roughly 40 million to 48 million tonnes of carbon-dioxide equivalent, both outlets reported.
CCAF’s 2025 Digital Mining Industry Report had previously found natural gas supplying 38.2% of surveyed miners’ electricity, with renewables at 42.6% and nuclear at 9.8%, while coal’s share had fallen to 8.9% from 36.6% in a 2022 estimate. Cambridge has not yet released a full source-by-source breakdown for the latest figures, but Neumueller attributed part of the reordering to stronger survey coverage of hydro-rich jurisdictions such as Ethiopia, where miners have expanded around low-cost power from the Grand Ethiopian Renaissance Dam.
A harder target for lawmakers
The timing matters for an industry that has spent years defending itself against proposals in Washington and Brussels targeting mining’s energy use, ranging from special levies to outright bans on proof-of-work operations. Environmental objections have also shaped institutional reluctance to hold Bitcoin directly, a concern that gained prominence after Tesla suspended Bitcoin payments in 2021 citing energy consumption, and one that ESG-mandated asset managers and pension funds have cited repeatedly since.
A mining sector approaching 60% low-carbon supply gives regulators less room to justify blanket restrictions on environmental grounds alone, though the 20% rise in absolute emissions leaves the debate over Bitcoin’s total climate impact unresolved rather than closed. Cambridge’s Bitcoin Electricity Consumption Index, the basis for the underlying methodology, tracks network hashrate, hardware efficiency and reported power sourcing rather than direct metering, meaning the estimates remain subject to revision as survey coverage expands.
Implications for listed miners
The shift also carries commercial weight for listed mining operators such as Marathon Digital, Riot Platforms and CleanSpark, whose margins are sensitive to power procurement costs. Hydropower contracts typically offer more predictable long-term pricing than natural gas, which remains exposed to geopolitical and seasonal volatility, a distinction that could feed into how these companies structure future energy agreements as they compete for capacity, including in the growing market for AI and accelerated-computing workloads. Cambridge’s data indicated only around 10% of surveyed miners had already allocated power capacity to such services, suggesting the crossover between mining and AI infrastructure remains at an early stage.
Cambridge said it expects to publish the full second edition of its Digital Mining Industry Report later in 2026, which should provide a more granular breakdown of the energy mix behind the preliminary figures.
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