In Europe, data centers — large buildings that house servers for internet and computing services — are consuming growing amounts of energy and water, but detailed information about their usage remains unclear. On September 30, 2026, the Dutch NGO Lighthouse Reports filed a complaint against the European Commission under the Aarhus Convention, an international agreement that ensures public access to environmental information. According to a 2025 report, data centers across the continent used 20.7 terawatt-hours of electricity, roughly equivalent to the total energy consumption of Croatia. They also used over 8 million cubic meters of water. While the European Commission shared these totals on an online dashboard, it did not provide individual data for each center. New data centers are opening regularly, and usage continues to rise. The energy demand from the sector jumped by 26% between 2023 and 2024, and water use increased by 52% during the same period. However, several countries have only provided partial data, making it difficult to get an accurate picture at the European level. The official dashboard includes many empty cells for key metrics. A 2024 directive prevents the European Union and member states from publishing data on individual operators. This was pushed for by major technology companies, who argued that such transparency could harm their commercial interests. As a result, the Commission can only share aggregated totals, without specific details about each data center. This lack of transparency makes it impossible for citizens or officials to compare the environmental impact of different centers. Since 2005, the EU has followed the Aarhus Convention, which ensures the public's right to access environmental information. Lighthouse Reports argues that the EU has created a "wall of silence" around data centers by withholding detailed information. The NGO says that the limited data available is not useful for analysis. Ten member states have even claimed they do not have the necessary data for their own data centers. In France, the Environment Ministry provided a file with incomplete and confusing data that is difficult to use. The compliance committee of the Aarhus Convention will decide in November whether the case is admissible. If the EU loses, it could be seen as violating its own climate goals. This case could set a precedent for other industries that are required to share environmental data. The European Commission has not yet responded to the complaint. On September 21, the Commission introduced a rating system for data centers, labeled from A to G, based on their energy efficiency, water use, and the proportion of renewable energy they use. This system will take effect in 2027, but it relies on ratios rather than actual measurements, making it impossible to determine the exact carbon footprint of a center. The EU aims to expand its data center capacity threefold to keep up with global competitors like the United States and China. The rapid development of artificial intelligence is increasing the demand for computing power. Meanwhile, local communities are protesting rising electricity costs. The 27 EU countries now face a dilemma: invest in more data centers to maintain global competitiveness or push for transparency about their environmental impact. In the Netherlands, nearly half of the data centers have not yet shared their data with the authorities.