Ethereum’s annual electricity consumption has plummeted to just 7.87 GWh following its transition to Proof of Stake, according to an audit by the Cambridge Centre for Alternative Finance (CCAF). The figure represents a reduction of more than 99.9% compared to the network’s power usage before The Merge, with associated carbon emissions now estimated at a mere 2.37 kilotonnes of CO₂-equivalent per year.
The dramatic improvement rewrites the environmental narrative for the world’s second-largest cryptocurrency, which once drew comparisons to medium-sized countries for its energy appetite. The CCAF report further notes that 56.4% of the electricity powering validators comes from sustainable sources, shifting the focus from the consensus mechanism itself to the carbon intensity of local grids where nodes operate.
However, the audit — based on an infrastructure analysis of roughly 8,522 nodes — also highlights worrying concentration at the hosting level. Approximately 62% of full nodes are located in the United States, Germany, Finland, and France, while just three service providers — Hetzner, Amazon Web Services, and OVH — collectively run around 40% of all examined nodes. This physical co-location on a small set of commercial cloud operators introduces tail risks, such as coordinated outages or regulatory interventions that could temporarily reshape network participation.
These findings come at a time when institutional and regulatory scrutiny of crypto’s environmental credentials is intensifying. The verifiable, third-party data gives asset allocators concrete figures for sustainability reports and undermines a longstanding objection to deploying regulated instruments on public blockchains. With on-chain real-world asset volumes surpassing $20 billion, much of it on Ethereum and its layer-2 networks, the improved energy footprint strengthens the case for institutional adoption.
Nevertheless, the report leaves important questions open: how liquid staking and restaking protocols might redistribute validators, the energy impact of layer-2 rollups posting blobs to mainnet, and the volatility of grid-mix carbon intensity as cloud regions shift their energy sourcing. As the Ethereum community celebrates an environmental milestone, the debate is shifting from energy usage to the structural centralization of its infrastructure.
