Bitcoin mining uses a lot of electricity. That part of the environmental debate is easy to establish. The harder part is putting the number in context, figuring out how much of that power comes from fossil fuels, and separating current data from old statistics that still circulate online.
The latest preliminary figures from the Cambridge Centre for Alternative Finance point to a bigger Bitcoin mining industry than the centre measured in 2024. At the same time, its reported low-carbon electricity share has increased. The result is a footprint that remains substantial, while its carbon intensity has changed.
Bitcoin's electricity use has climbed sharply
Cambridge researcher Alexander Neumueller presented preliminary findings from the centre's next digital mining study in July 2026. The estimate put Bitcoin mining's annualized electricity consumption at about 190 TWh in December 2025, compared with 138 TWh in June 2024. That represents a 38% increase over the period.
The 190 TWh figure needs one clarification. It is an annualized estimate based on the network's power demand at that point, rather than a record showing that miners consumed exactly 190 TWh during calendar year 2025. Cambridge's methodology models network electricity demand because Bitcoin has no central operator collecting a worldwide electricity bill.
For scale, the International Energy Agency puts global electricity consumption at about 28,200 TWh in 2025 in its latest full-year dataset. A 190 TWh Bitcoin mining run rate would therefore amount to roughly 0.7% of global electricity use. That is a sizeable demand from one digital network, although claims that Bitcoin uses several percent of the world's electricity go well beyond the current data.
The wider Bitcoin economy also includes consumer-facing services, from payments to trading platforms and crypto-based entertainment. For example, some sites offer a live bitcoin casino where users can use cryptocurrency for online casino play. These services rely on the Bitcoin ecosystem, although the electricity consumed by Bitcoin mining comes from securing and maintaining the proof-of-work network itself.
The carbon footprint depends on the power source
A terawatt-hour is a measure of electricity. It does not tell you how much carbon was released to generate that electricity. A mining operation supplied by hydropower has a very different emissions profile from one relying on coal-fired generation.
Cambridge's 2025 digital mining study estimated annual Bitcoin electricity consumption at 138 TWh and associated emissions at 39.8 million tonnes of CO2 equivalent. The research drew on information from 49 mining companies across 23 countries, representing about 48% of global Bitcoin mining activity at the time.
The newer preliminary figures put annualized emissions at around 48 million tonnes of CO2 equivalent, up about 20% from the earlier estimate. Electricity demand grew by 38% over the same comparison period. Emissions therefore increased more slowly than power consumption, which is consistent with the reported shift toward lower-carbon electricity.
That distinction matters when assessing Bitcoin's climate impact. Two mining facilities can use the same amount of electricity and produce very different emissions depending on the grid or generation source supplying them.
More mining power is coming from lower-carbon sources
The preliminary Cambridge figures show the low-carbon share of Bitcoin mining's electricity mix rising from 52.4% to 59.4% between the two measurement periods. Hydropower also moved ahead of natural gas as the largest individual source in the preliminary data.
The previous Cambridge survey gives a closer look at the mix. Renewables supplied 42.6% of reported mining electricity, including 23.4% from hydropower, 15.4% from wind and 3.2% from solar. Nuclear power contributed another 9.8%. Fossil fuels accounted for 47.6%, with natural gas at 38.2%, coal at 8.9% and oil at 0.5%.
The economics help explain why miners pay so much attention to electricity markets. Power is one of the biggest operating expenses in proof-of-work mining, so companies have a strong incentive to find inexpensive sources and use available generation capacity. Hydropower, wind and solar can become attractive in markets where excess generation is available at competitive prices.
The renewable shift does not make mining impact-free
A larger low-carbon share changes Bitcoin's emissions profile, although it does not eliminate its resource demands. Mining still requires specialized hardware, large facilities and substantial electricity. The network's total power requirement has also risen, even as its reported energy mix has become cleaner.
Hardware creates another environmental consideration. Bitcoin miners rely heavily on application-specific integrated circuit, or ASIC, machines designed for mining. Those machines have finite useful lives and can become obsolete when newer, more efficient hardware enters the market. Cambridge's previous research estimated around 2.3 kilotonnes of Bitcoin mining e-waste in 2024. The same study reported that miners said 86.9% of decommissioned hardware was resold, repurposed or recycled.
Mining can also respond to electricity-grid conditions. Cambridge reported that miners curtailed 888 GWh of electricity in 2023, meaning some operations reduced their power consumption when market or grid conditions made that worthwhile. That flexibility has become part of the industry's relationship with power markets.
