EU faces Aarhus complaint over data centre energy secrecy as AI demand grows

Lighthouse Reports lodged the complaint this week under the Aarhus Convention, a legally binding treaty that gives the public rights to information and participation in environmental decision-making. POLITICO reported the filing on 30 September. The European Commission did not respond to POLITICO's request for comment.

The timing is not accidental. Public opposition to power-hungry AI data centres is growing across Europe while energy prices rise. The EU has publicly declared a target of tripling data-centre capacity in the coming years to keep pace with the US and China.

According to the Commission's own figures, Europe's data centres used 20.7 terawatt-hours of electricity in 2025, about as much as the entire nation of Croatia consumes, and more than 8 million cubic meters of water. That is a 26% increase in electricity use and 52% in water use from 2024. But those totals come from incomplete data collected by the Commission and have only been published in aggregate.

What the complaint actually says

Lighthouse Reports, a Netherlands-based non-profit that runs cross-border investigations, argues the Commission is letting operators keep consumption details under wraps and dodge scrutiny. "The Commission sits at the top of an edifice of non-disclosure encompassing the vast majority of the EU," the complaint says, according to POLITICO. "Siding with commercial secrecy over the public's right to know erodes legitimacy and damages trust further."

The legal backdrop is a 2024 law that banned Brussels and EU capitals from disclosing "all information and key performance indicators for individual data centers." POLITICO reports the measure followed lobbying from tech giants citing commercial interests.

The challenge faces its first test in November, when the Aarhus Convention Compliance Committee meets to decide whether it is admissible. If it clears that hurdle, Aarhus could later find the EU in breach of its obligations under the convention, which the bloc has been party to since 2005.

The Commission has tried to head off the criticism with a transparency label presented last week. The label requires operators to grade energy efficiency, water usage and clean power uptake from A to G starting next summer. Lighthouse Reports said the rules still conceal total energy consumption and other metrics needed to assess carbon footprints. "The choice of ratios over actual consumption figures has no basis in technical constraints, it is a choice that favors the industry over public interest," the complaint says.

The EU's energy chief, Dan Jørgensen, told POLITICO in an interview that big power consumers risk undermining the bloc's own targets if they are not held in line with them. Diego Solier, a conservative member of the European Parliament working on the EU's digital capacity push, said transparency should be the starting point but must be "proportionate."

Why it matters beyond Brussels

The dispute sits on top of a broader investment story. In a 30 September note, Andreessen Horowitz says tech contributed roughly 76% of the S&P 500's total earnings growth in 2026 as of late August. That growth was driven by a buildout of semiconductors, power and networking funded largely by hyperscaler profits and increasingly by debt. The firm argues demand for compute still outpaces supply, with even older A100 GPUs pricing at or above their levels at the start of the year.

The same report cautions that adoption remains shallow: nearly 30% of S&P 500 companies report some "quantifiable impact" of AI, but only about 2% track any metric, and as of April barely 2% of US households paid for an AI service. That gap between spending and measured use is exactly the terrain the Aarhus complaint targets. Without per-facility consumption data, neither regulators nor investors can verify what the buildout costs in power and water.

Elsewhere, electrification is moving faster than the grid debate. BloombergNEF reported on 30 September that global sales of medium- and heavy-duty electric trucks hit a record 158,000 units in the first half of 2026, up 75% year on year, with more than nine in ten sold in China. Electric trucks reached about 20% of total truck sales globally and 5.5% in Europe, while the US battery-electric truck market has slowed to a near standstill.

For now, the EU's answer is procedural. A November admissibility ruling will decide whether the Commission has to defend its data-centre secrecy in front of the convention's compliance committee, or whether the wall of silence stands.