Bitcoin Sustainability Indicators
Last updated December 31, 2025
Under Article 5 of Delegated Regulation (EU) 2025/422 (D.Reg. (EU) 2025/422) supplementing the Markets in Crypto‑Assets Regulation (“MiCA”), crypto‑asset service providers (“CASPs”) must publish transparent sustainability indicators for each crypto‑asset they provide. The table below follows Annex III of the regulation and summarises the mandatory and supplementary indicators for Bitcoin. Narrative explanations and methodology follow beneath the table.
TABLE 1: PRINCIPAL ADVERSE EFFECTS
| Field | Required element | Relai disclosure for Bitcoin | Key sources |
| S.1 | Name of the reporting CASP | Relai | N/A |
| S.2 | Legal Entity Identifier | Relai EU SASU: 934 814 062 R.C.S. | Company register |
| S.3 | Crypto-asset | Bitcoin (BTC) | N/A |
| S.4 | Consensus mechanism and fee incentives | Proof-of-Work; miners earn block subsidies plus transaction fees for validating blocks. Fees are denominated in satoshis per byte. |
Bitcoin Core Developers. (n.d.). Bitcoin. GitHub.
GitHub repository |
| S.6/7 | Reference period | Calendar year 2024 (1 Jan 2024 – 31 Dec 2024). Relai will update the information at least annually and whenever material changes occur. | N/A |
| S.8 | Annual energy consumption associated with validation and ledger maintenance | The Cambridge Centre for Alternative Finance (CCAF) estimated that Bitcoin’s network consumed approximately 138 TWh of electricity in 2024, equivalent to about 0.5% of global electricity consumption. Relai therefore reports that the network uses 138 TWh annually. | CCAF 2025 study |
| S.9 | Methodology and data source | Relai does not operate mining nodes and therefore relies on third-party estimates. The 138 TWh figure comes from the CCAF’s 2025 survey of 49 mining firms and represents the network-wide electricity use. | CCAF 2025 study; CarbonCredits report using Digiconomist data; Crypto.news analysis of Daniel Batten’s BEEST model. |
TABLE 2: SUPPLEMENTARY INDICATORS
| Field | Indicator | Relai disclosure and metrics | Key sources |
| S.10 / S.11 | Greenhouse-gas (GHG) emissions – Scope 1 (emissions from nodes) and Scope 2 (electricity purchased) | The CCAF report estimates that Bitcoin mining produced 39.8 million tonnes CO₂e in 2024. When accounting for methane-powered mining and flared-gas mitigation, net emissions fall to ~37.6 Mt CO₂e. Relai therefore reports 39.8 Mt CO₂e for the total network and 37.6 Mt CO₂e for net emissions after mitigation. | CCAF 2025 study. |
| S.12 | Carbon-intensity of mining (g CO₂e/kWh) | The CCAF study measured the Bitcoin network’s emissions intensity at 288.2 g CO₂e per kWh in 2024, down ~50% since 2022. | CCAF 2025 study. |
| S.13 | Share of renewable and low-carbon energy used | CCAF’s 2025 report found that 52.4% of Bitcoin’s electricity comes from sustainable sources (42.6% renewables and 9.8% nuclear). Hydropower accounts for 23%, wind 15%, solar 3%, and nuclear ~10%. Natural gas has overtaken coal as the largest single fuel, supplying 38.2% of electricity, while coal has fallen to 8.9%. | CCAF 2025 study. |
| S.14 | Renewable-energy certificates or offsets used | Bitcoin mining is decentralized; miners may purchase renewable energy certificates (RECs), but comprehensive data are unavailable. Relai does not own or operate mining hardware and therefore cannot report REC volumes. Some miners use flared-gas or landfill methane to power mining rigs; CCAF estimates that methane utilisation offsets 5.5% of total network emissions. Daniel Batten’s BEEST model suggests off-grid methane-powered mining helped the network mitigate 7.3% of its emissions in 2023. | CCAF 2025 study; Batten’s BEEST model. |
NARRATIVE EXPLANATION AND CONTEXT
Electricity consumption and GHG emissions
The Cambridge Centre for Alternative Finance (“CCAF”) collects confidential data from major mining companies to estimate Bitcoin’s energy use. Their 2025 report reveals that the network consumed about 138 TWh of electricity in 2024. This equates to about 0.5% of global electricity consumption. Using this consumption and regional grid mixes, CCAF calculated total network emissions of 39.8 Mt CO₂e. Emissions intensity decreased sharply to 288.2 g CO₂e/kWh thanks to more efficient mining equipment and greener energy mixes. By comparison, Digiconomist’s energy consumption index (a widely cited but more conservative model) suggests Bitcoin consumed ~176 TWh and emitted ~98 Mt CO₂e; Relai discloses this in the methodology section for transparency but bases its figures on CCAF due to its broader survey coverage. Relai notes that these estimates come with uncertainty because reporting is voluntary in a decentralized network.
Sustainable energy mix and methane mitigation
CCAF’s 2025 survey shows a major shift in Bitcoin’s energy mix. Over 52.4% of electricity used by miners comes from sustainable sources, with hydro, wind, and nuclear being the largest contributors. Natural gas now powers 38.2% of mining, while coal usage has fallen to 8.9%. The report highlights that more than 70% of surveyed mining firms are actively implementing climate‑mitigation measures. One mitigation strategy is using waste methane from flaring or landfills to generate electricity. CCAF estimates that methane‑powered mining offsets 5.5% of the network’s emissions.
Climate‑tech investor Daniel Batten, co‑author of the BEEST model, adds that off‑grid miners using vented methane reduced emissions by 7.3% in 2023 and improved emission intensity by 29% relative to 2021. Batten also projected Bitcoin’s emissions at ~42 Mt CO₂e for the period under review, close to CCAF’s estimates, and emphasises that each Bitcoin transaction is becoming net‑emission‑reducing due to these mitigation strategies.
Positive impact of Bitcoin on the environment
To provide a comprehensive analysis of Bitcoin’s impact on the environment, it is important to note that Bitcoin mining’s energy consumption figures can be misleading when viewed in isolation. Isolated energy consumption figures do not account for the network’s incentives to utilize stranded energy, i.e. excess power that would otherwise be wasted, and the positive incentives for renewable infrastructure that Bitcoin mining generates.
Miners often strategically locate operations near renewable energy sources, such as hydroelectric or solar plants, where surplus electricity is generated during low-demand periods but cannot be stored or transmitted efficiently with current technology. By consuming this otherwise unused energy, Bitcoin mining enables producers to monetize it, securing the Bitcoin network while rewarding energy providers. This process does not represent incremental demand on the grid; instead, it repurposes energy that would have been produced regardless, turning potential waste into a productive asset (securing the Bitcoin network and generating revenues for the miner) without displacing other uses. If the electricity could be directed to alternative purposes profitably, market forces would ensure it is, underscoring that Bitcoin mining optimizes rather than exacerbates energy consumption.
Furthermore, Bitcoin mining creates powerful economic incentives for the expansion of renewable energy infrastructure. By providing a consistent, location-flexible demand for surplus power, it encourages investment in new renewable projects, as producers can achieve higher returns by selling excess output to miners. Thanks to Bitcoin mining, a renewable energy provider faces less financial risks (Bitcoin can be mined when there is no demand for electricity on the grid), higher potential financial rewards (via mining rewards) and thus higher incentives for expanding renewable energy sites or creating new ones. Collectively, these dynamics position Bitcoin mining as a catalyst for greener energy practices, potentially accelerating the transition to sustainable sources.
Implications for Relai
Relai provides non‑custodial exchange and wallet services and does not operate mining infrastructure. Nevertheless, under Delegated Regulation 2025/422 and ESMA guidance, it must disclose principal adverse impacts of the crypto‑assets it offers. Relai will host this disclosure free of charge and downloadable on its website. The company will review the data annually; the next scheduled review is 31 March 2026, or earlier if significant new research emerges. Disclosures will include the date of publication and last update to ensure compliance with MiCA’s transparency and comparability requirements.
Methodology notes
- Data selection: When multiple reputable sources provide different estimates, Relai favors datasets that disclose their methodology and offer peer‑reviewed or survey‑based results (e.g., CCAF). Other models, such as Digiconomist, are acknowledged for comparison.
- Units: Energy consumption is reported in terawatt‑hours (TWh). Emissions are reported as million tonnes of CO₂ equivalent (Mt CO₂e). Carbon intensity is provided as grams of CO₂e per kilowatt‑hour (g CO₂e/kWh).
- Limitations: Bitcoin’s decentralized nature means there is no central database of energy use or emissions. Estimates vary due to differing assumptions about mining hardware efficiency, energy sources and geographic distribution. Actual numbers may differ from reported figures, and Relai will update its disclosure as new data become available.
Update schedule
Relai commits to updating this disclosure annually and promptly when material changes in Bitcoin’s environmental impact are identified.
Footnotes:
¹ https://www.jbs.cam.ac.uk/faculty-research/centres/alternative-finance/