Sensor-measured cooling cut Virgin Media O2's cooling power by 15 per cent – one of three levers in play

Sensor-measured cooling cut Virgin Media O2's cooling power by 15 per cent – one of three levers in play

Europe's AI boom demands more data centres – but the power grid can barely cope with the ones that exist. Five start-ups want to do something about it: sensor-measured cooling, battery-driven grid flexibility, and waste heat that warms swimming pools.

Europe needs more data centres to build out AI capacity, but the new facilities add further load to already strained power grids. This contradiction has become a bottleneck in itself: according to Euronews, the power squeeze is now making it harder to connect and build new facilities.

In the same week the European Commission presented its data centre energy efficiency package, Euronews published a survey of five European companies offering three main answers to the problem: using less power on cooling, shifting power consumption in time with batteries, and exploiting the waste heat that would otherwise be lost.

How big is the problem?

The figures vary with geographic scope and time horizon – and should be kept apart.

The British think tank Ember estimates that data centres' electricity consumption across Europe will rise from 96 terawatt hours (TWh) in 2024 to 236 TWh in 2035, according to Euronews.

For the EU alone, the International Energy Agency (IEA) works with a different set of figures: around 68 TWh in 2024, expected to nearly double to 114 TWh by 2030 – more than 3 per cent of the EU's total electricity consumption. The two estimates thus cover different areas and different years, and cannot be compared or combined.

The context is the EU's ambition to triple data centre capacity within five to seven years, while the Commission is now proposing a common energy labelling scheme for the industry. It is against this backdrop that the start-ups are positioning themselves.

Lever 1: Measure and control the cooling

A significant share of data centres' power goes to cooling, and this is where two of the companies strike first.

In 2024, EkkoSense installed its sensor system across 20 data centre rooms operated by Virgin Media O2. The system reduced cooling energy by an average of 15 per cent, according to Virgin Media O2 – equivalent to over £1 million (around €1,166,588) saved annually and 760 tonnes of carbon dioxide under location-based accounting. The method is simple in principle: sensors show where the heat actually sits in the room, so that cooling can be directed where it is needed instead of running at full power everywhere.

Etalytics took a software-based route. Last year, the Japanese technology company NTT tested etalytics' simulation system at its data centre in Bonn. The electricity consumption of the chillers fell by 19.1 per cent in the first months of the trial period, and NTT expects the savings could reach up to 25 per cent over a full year, according to Euronews.

A third company, Submer, goes further physically: immersion cooling with liquid instead of air. Customer Telefónica has claimed in a blog post that Submer's solution "uses a new liquid cooling technique to increase energy efficiency by up to 50 per cent, reduce carbon emissions from the use of refrigerant gases, reduce the footprint and improve the total cost of ownership (TCO) of data centres". A clear caveat is warranted: this is a customer statement, not an independently verified figure.

Lever 2: Shifting consumption in time

Even with better cooling, the power must come from the grid – and it is the grid connection that is the bottleneck. GridBeyond attacks the time dimension: their software controls batteries so that data centres can draw less power from the grid during periods of strain.

The software is installed at two data centres in Dublin owned by the Singapore-based Keppel DC REIT, providing a combined 8 MW of flexible capacity, according to GridBeyond. Measured against the TWh estimates, that is a modest amount, but the principle is relevant for grid operators: a data centre that can flex its consumption is easier to connect than one that requires constant supply.

Lever 3: The heat that otherwise disappears

Deep Green turns the problem on its head: instead of treating waste heat as a waste problem, the company places compact computing units with actors that need heat – including swimming pools and district heating networks. Liquid warmed by the servers carries the heat into the neighbouring building's heating system.

The potential is not trivial. The European Commission estimates that recovering around half of all waste heat from European data centres would equal the total heating demand of four million European households.

What the figures actually show – and what they don't

There are thus three concrete levers: cooling efficiency (EkkoSense, etalytics, Submer), grid flexibility (GridBeyond) and waste heat recovery (Deep Green). All the facilities mentioned have named operators: Virgin Media O2, NTT, Telefónica and Keppel DC REIT.

But one precise caveat applies to the entire technical picture: every single efficiency figure – 15 per cent at EkkoSense, 19.1 and up to 25 per cent at etalytics, up to 50 per cent at Submer, 8 MW at GridBeyond – comes from the companies themselves or from their customers, as reported by Euronews. None of the figures is independently verified, and the customers obviously have an interest in the projects they have invested in appearing successful.

The open question, therefore, is not whether the technologies work in trial projects – the figures suggest they do – but whether they can scale fast enough to matter against a consumption that, according to Ember, could more than double in Europe by 2035. The Commission's new efficiency package could accelerate the rollout; grid bottlenecks could do the same by making efficiency a condition for connection. For now, the answer to whether five companies' approaches can bend the curve on 236 TWh is entirely open.