Can Europe keep the data centre boom clean?

As I peeked out from the airplane window on my way to Finland, a giant hole in the ground stared back up at me. I thought I was seeing a surface mine, but no: Microsoft is building a giant data centre site close to Helsinki. So far, most data centres in Europe have been built in Western and Central Europe, but the “AI boom” is now driving data centre construction in European countries with cheap, renewable electricity: mostly the Nordics, Spain, and Portugal. Today, the EU has around 3,000 data centres – see our map here. The European Commission aims to triple the EU's data centre capacity by 2035. It's an ambitious goal, but if successful, that tripling would still result in only a fraction of the capacity in the US or China. An even bigger challenge is fitting data centres into our energy system without sacrificing Europe's transition to clean power. The European Commission is currently preparing a sustainability rating scheme for data centres around the bloc, using the same labelling system as we see on our household appliances, from a green A to a red G. From summer 2027, this scheme will classify data centres' energy and water usage efficiency. Introducing these standards is the EU's way to push Big Tech companies toward more transparency. It is expected that the label will later be tied to EU funding to incentivise data centre operators to make their activities as sustainable as possible. But the plan has a massive loophole: the rating scheme will be based on data collected and reported by the operators themselves, who are notorious for dodging questions about their business's real environmental impact. So far, only 36% of data centres required to report on their energy efficiency to the European Commission have done so. Worse still, the total environmental impact of these centres is complex and difficult to verify, from heat escaping into the air to water use and pollution, as well as the impact of the power plants used to run them. What’s feeding the data centre beast? While the EU is coming up with schemes and regulations, data centre developers are promising to power their operations with low-carbon renewable or nuclear energy. Jon Summers, professor and scientific leader in data centres at Research Institutes of Sweden, confirms that Big Tech companies are indeed helping push growth in the renewable sector. “Firms like Microsoft or Google come in and put money down on the development of renewable energy. It may not be the energy that they use, but they are pushing for the development,” he told The European Correspondent. But with more and more data centre projects being approved across the continent, it's clear that renewable development and grid updates will struggle to keep up with the data centre boom in the coming years. Operators are already increasingly seeking direct connections to gas-fired power plants. The European Data Centre Association, whose members include Amazon, Google, and Microsoft, is calling for gas-fired electricity to support AI growth, “while waiting for grids, nuclear reactors, and renewable energy storage to catch up.” In Ireland (one of Europe’s major AI hubs) fossil-fuel power plants are already being reactivated, while plans for new ones are being drafted. But more gas in the system goes directly against Europe's climate commitments and efforts to reduce dependence on pricey fossil fuel imports. Can we do better? Instead of large gas-fired data centres like those in the US, a network of fewer, smaller, and well-distributed centres could be a better fit for Europe's energy system, Summers said. But there are also other ways to mitigate their negative impacts. After landing in Finland, I visited a heat pump plant run by Finnish state-owned energy company Fortum, right next to the data centre construction site I saw from the plane. Its location is no coincidence: when the data centre is finished, most of the waste heat it produces will be recycled there and sent to the local district heating system instead of just evaporating into the air. Hundreds of kilometres of underground pipes supply around 250,000 households around Helsinki with heat. Fortum will use the data centre next door to provide about 40% of this heat, workers told me as we were climbing the stairs to the facility's roof. From there, we saw a 40-metre-tall silo that can hold 20,000 cubic metres of hot water. It serves as heat storage that can be used during peak hours – winter evenings, for instance, when Helsinki's residents are coming back from work desperate for their daily round of sauna or a hot bath. Solutions like Fortum's, however, can't be easily replicated everywhere. It relies on existing district heating systems, which so far are mostly limited to Northern and Central Europe. Given the varied and plentiful environmental impacts of AI systems, including high risk of water scarcity in water-stressed regions, we'll need many more innovative solutions to solve the puzzle of sustainable AI.