Bitcoin mining consumed more electricity than ever in 2025, but its carbon footprint increased more slowly than its power demand, according to preliminary research from the Cambridge Centre for Alternative Finance.

The findings point to a larger share of electricity coming from low-carbon sources, with hydropower becoming the sector’s largest single energy source. At the same time, higher activity across the Bitcoin network continued to push total emissions upward. Cambridge also found that many mining companies are exploring artificial intelligence and high-performance computing, although actual adoption remains limited.

Bitcoin Mining Power Use Rose Faster Than Emissions

Bitcoin’s annual electricity consumption reached about 190 terawatt-hours by December 2025, Cambridge’s preliminary research showed. That was a significant increase from 138 terawatt-hours in June 2024.

Alexander Neumueller presented the figures at the inaugural Energy Investors Forum in Dallas before the release of Cambridge’s second Digital Mining Industry Report.

Estimated carbon emissions rose more slowly than electricity use over the same period. Cambridge estimated emissions increased from about 40 million metric tons of carbon dioxide equivalent to 48 million metric tons. That represented growth of roughly 20%, compared with an approximately 38% increase in electricity consumption.

The difference was largely attributed to changes in the electricity mix used by Bitcoin miners. Low-carbon energy sources accounted for 59.4% of total power use, up from 52.4% in the previous study. Hydropower moved ahead of natural gas to become the largest individual source of electricity for Bitcoin mining. For policymakers, grid operators and companies assessing the sector, the figures highlight why both total electricity demand and the source of that electricity matter when evaluating mining’s environmental impact.

Hydropower Became the Largest Source in the Mining Energy Mix

The research presents a more nuanced picture of Bitcoin mining’s environmental profile. Total electricity demand continued to rise, but each unit of electricity used by miners carried a lower carbon intensity than before, slowing the rate of emissions growth.

Cambridge based its latest findings mainly on survey responses from mining companies representing just over half of the global Bitcoin hashrate. Neumueller said participation improved compared with the previous report. However, survey-based research can be influenced by which companies and regions are more willing to disclose operational details, making the forthcoming full report important for understanding the methodology and regional breakdown behind the preliminary estimates.

Cambridge’s earlier report estimated annual Bitcoin mining electricity use at 138 terawatt-hours and emissions at 39.8 million metric tons of carbon dioxide equivalent. In that study, sustainable sources, including renewables and nuclear power, supplied 52.4% of electricity used by the sector.

Several factors shaped the latest findings:

• Electricity demand increased to about 190 terawatt-hours as more mining machines joined the network.
• Low-carbon sources rose to 59.4% of the reported electricity mix.
• Hydropower replaced natural gas as Bitcoin mining’s largest power source.
• Ethiopia attracted attention as a mining location after additional hydroelectric generation became available.

Increased activity on the Bitcoin network appears to have outweighed improvements in mining hardware efficiency. Newer machines can perform more calculations while using less electricity, but rising competition among miners pushed total power consumption higher.

Geography also affected the reported energy mix. Broader survey coverage included more mining operations in countries with substantial hydropower resources, including Ethiopia. New electricity capacity from the Grand Ethiopian Renaissance Dam has helped draw mining businesses seeking lower-cost power. Changes in survey participation can also influence estimates of the global energy sources used by Bitcoin miners.

Cambridge Says AI and HPC Interest Is High but Adoption Remains Early

Cambridge also examined whether Bitcoin miners are moving into artificial intelligence and high-performance computing, often referred to as HPC. About one in ten surveyed companies had already allocated part of their power capacity to AI or accelerated computing services.

Interest was much higher than current participation. More than 40% of miners that had not entered the sector said they were actively considering AI or high-performance computing. Around 10% said they had no plans to pursue either business. Neumueller cautioned that interest alone should not be treated as a firm commitment.

Mining companies are increasingly valued by some investors for their access to land and electricity, rather than only for their Bitcoin production. Several publicly listed miners have announced AI hosting agreements or plans to convert some facilities. Cambridge’s survey indicates that such projects remain limited across the broader industry.

Companies cited stronger financial stability and wider revenue opportunities as major reasons for considering diversification. High capital costs were identified as the largest obstacle. Many operators also said they preferred to keep Bitcoin mining as their main focus.

Converting a Bitcoin mining site into an AI data center requires substantial investment. AI facilities need advanced cooling, stronger networking, reliable infrastructure and higher engineering standards. Access to suitable land and electricity is often not sufficient on its own, which helps explain the gap between widespread interest and limited deployment reported by Cambridge.

Despite those hurdles, nearly nine out of ten survey participants said they expect AI and high-performance computing to become more common across the mining sector in the coming years. Many also identified opportunities in power generation and grid services, reflecting the increasing value of reliable electricity access.