EU's new data center rating has a green certificate loophole

The European Commission has proposed on Monday a new EU-wide rating system to assess the energy and water efficiency of data centers. The framework aims to bring transparency to a sector projected to consume 3.2% of the bloc’s electricity by 2030. However, a loophole in the criteria could allow fossil-fueled data centers to earn high ratings by offsetting their emissions with green certificates. 

The proposed rating system will apply to data centers with a capacity above 500 kW, covering roughly 770 facilities that are required to report under existing EU rules. Each center will receive a label from A (most efficient) to G (least efficient) based on its performance across five key metrics: energy consumption, water consumption, waste heat reuse, clean energy generation, and grid flexibility. 

This proposal comes at a time when the Commission aims to triple the bloc's data center capacity over the next five to seven years to support its AI and digital autonomy ambitions. Teresa Ribera, Executive Vice President for the Green Deal, emphasized that “tripling our data centre capacity cannot mean tripling the pressure on our grids, our water and our energy bills.”

The first labels are expected in 2027, with the system subject to a two-month scrutiny period by the European Parliament and Council before entering into force. The EU’s 2024 data centers electricity consumption stood at 68 TWh, with projections showing a rise to 114 TWh by 2030.

Incentivizing grid flexibility and waste heat reuse

The rating system rewards data centers that contribute to grid stability through demand response, on-site renewable generation, and battery storage. It also incentivizes waste heat reuse, with the Commission estimating that capturing 50% of Europe’s data center waste heat could meet the heating needs of 4 million households.

The scheme builds on existing reporting obligations under the Energy Efficiency Directive, which requires data centers to disclose their Power Usage Effectiveness (PUE), Water Usage Effectiveness (WUE), Energy Reuse Factor (ERF), and Renewable Energy Factor (REF). 

Setting data center performance standards

Alongside the rating system, the Commission launched a public consultation on minimum energy performance standards (MEPS) for data centers, open until December 14, 2026. Unlike the labels, these standards would set hard requirements.

A key requirement concerns PUE, an industry-standard measure of data center energy efficiency. It is calculated by dividing a facility's total energy consumption by the energy consumed by its IT equipment. A PUE of 1.0 means all energy goes to IT equipment, with no overhead for cooling or power conversion. The proposed thresholds are a PUE below 1.5 for existing centers by 2030, below 1.3 for new centers by design, and below 1.4 within three years of operation. In the Netherlands, new data centers must already have a PUE of 1.2 or less.

For water, the standards would cap WUE at 0.4 m³/MWh by 2030. On energy sourcing, they would require a Renewable Energy Factor of 100%, meaning data centers must run entirely on renewable energy by the same year. The standards are expected to become legally binding in Q2 2027, with enforcement falling to EU member states.

Buying a green label 

A critical flaw in the proposal could undermine these goals. As EUobserver points out, the proposed regulation would allow data centers to offset fossil fuel use by purchasing annual green certificates. This means that facilities powered by coal or gas at night can still claim a “green” label if they buy enough renewable energy credits to balance their annual consumption.

Because the rules do not require hourly or seasonal matching of renewable energy use, fossil-fueled centers could meet the criteria without reducing their carbon footprint. The problem also extends beyond the labels. If the 100% REF requirement can likewise be met with certificates, the loophole would weaken the binding performance standards as well.

Industry groups have raised a different objection, criticizing the uniform labeling criteria for ignoring regional differences in climate and water stress, which they say could distort efficiency metrics.

Compliance challenges

Compliance with mandatory reporting has been inconsistent. A Commission official speaking on condition of anonymity told reporters that only half of the 770 data centers required to disclose metrics on energy and water usage did so this year. 

The Commission acknowledges these challenges but insists the rating system is a step toward greater transparency and sustainability, and has committed to reviewing its effectiveness by the end of 2028. By then, it should be clearer whether a label that can be earned through annual certificates tells consumers and regulators much about a data center's real environmental footprint.