Cambridge: Ethereum’s PoS energy use trails lower-end estimates

A new report from the Cambridge Centre for Alternative Finance places Ethereum’s post–Merge energy footprint among the less energy-intensive proof-of-stake (PoS) networks, even as it remains higher in absolute consumption than most single-network peers. The study estimates that Ethereum uses about 7.87 gigawatt-hours (GWh) of electricity per year.

More importantly for sustainability comparisons, Cambridge also calculated Ethereum’s energy intensity relative to market value, finding roughly 33 kilowatt-hours (kWh) per $1 million. That figure ranks as the second-lowest among the PoS networks assessed, behind BNB Chain.

Key takeaways

• Cambridge estimates Ethereum consumes about 7.87 GWh annually, based on modeled electricity use at the wall.
• Ethereum’s energy intensity is estimated at ~33 kWh per $1 million, the second-lowest among the PoS networks in the study.
• Solana is estimated to use the most electricity among the PoS networks considered, at ~13.48 GWh per year.
• Cambridge attributes Ethereum’s remaining emissions mainly to the electricity grids powering its validators and node operators, rather than network operations based on mining.

How Cambridge built its Ethereum power model

The Cambridge researchers estimated electricity use by measuring how much power Ethereum nodes consume under different software-client setups. According to the report, they modeled electricity demand across 20 combinations of the Ethereum network’s main software clients, using assumptions tied to typical home and professional hosting environments.

In the study’s modeling, a “typical home” node setup draws about 18 watts, while a more capable workstation setup uses roughly 153 watts. Cambridge then used Ethereum’s observed mix of residential and professionally hosted nodes to estimate an average power draw of approximately 105 watts per node.

To scale this to network-wide consumption, the report counted around 8,522 discoverable full nodes. Of those, 64% were described as running in cloud or enterprise environments, with the remaining 36% on residential connections. These proportions matter for sustainability comparisons because hosting environments can differ in electricity sourcing and energy efficiency.

Energy intensity vs. market value: why it changes the comparison

While absolute electricity consumption is one dimension of sustainability, Cambridge also calculated energy intensity adjusted for market value. This approach aims to answer a practical question for investors and policymakers: how much electricity a network uses relative to the scale of economic value attributed to it.

On this basis, Ethereum’s estimated ~33 kWh per $1 million places it near the lower end among PoS systems assessed—second only to BNB Chain. Solana, by contrast, tops the group in Cambridge’s dataset for both absolute annual electricity consumption and energy intensity.

The report estimates Solana uses about 13.48 GWh per year, corresponding to roughly 283 kWh per $1 million in market-value-adjusted energy intensity. Cambridge notes that this is around 8.5 times Ethereum’s figure, and that the networks in the comparison consumed about 38 GWh combined.

For readers, the implication is that rankings can differ depending on whether the metric is raw consumption or market-value-adjusted intensity. Cambridge’s dual approach highlights that sustainability arguments built on electricity alone may miss an important dimension of “efficiency per dollar of market value,” even if both metrics ultimately reflect real-world electricity usage.

What the post–Merge shift means for emissions

The study’s framing is closely tied to Ethereum’s transition from proof-of-work to proof-of-stake. Ethereum moved from mining-based validation to staking-based validation through the Merge in September 2022. After that change, the energy-intensive mining process that used specialized hardware to compete for block rewards was removed, replaced by validators securing the network by staking Ether.

Cambridge’s report builds on earlier estimates that the Merge sharply reduced Ethereum’s electricity use. After the upgrade, network power estimates showed a reduction of more than 99.9%, reflecting the removal of proof-of-work operations.

With mining gone, Cambridge says Ethereum’s remaining emissions are now driven primarily by the electricity grids supplying its nodes and validators. The report estimates that about 56.4% of Ethereum’s electricity mix comes from renewable and nuclear sources, with the remaining 43.6% attributed to fossil fuels.

This distinction is important for what comes next. Even if energy consumption stays relatively stable, the emissions profile could improve (or worsen) as electricity generation in the regions hosting nodes changes, or as enterprise and cloud operators shift their sourcing toward cleaner power.

Why these numbers matter for investors and policymakers

Cambridge describes the work as among the most detailed assessments yet of Ethereum’s post–Merge energy footprint. That matters because Ethereum is frequently used as a case study in broader sustainability debates around PoS blockchains—especially when regulators and institutional participants weigh environmental and operational considerations alongside financial risk.

By estimating node-level power draw, scaling it by observable node counts, and comparing results across different PoS ecosystems using consistent methodology, the report gives stakeholders a more current basis for evaluating claims about blockchain energy use after major protocol changes.

Still, the study’s methodology also implies where uncertainty may remain. The results depend on assumptions about node power consumption across client combinations and hosting types, as well as how discoverable node counts represent the broader network. The direction of change after the Merge is clear, but the granularity of the current baseline will continue to hinge on how node operations evolve.

Going forward, readers should watch for updated third-party assessments as node distribution, hosting practices, and grid energy mixes change over time—particularly because, under PoS, sustainability debates increasingly pivot from “mining infrastructure” to the electricity sources powering validators and node operators.