Europe’s Digital Backbone Requires Reliable Power
Data centers are the backbone of Europe’s digital economy. They host the cloud services, AI workloads, and enterprise systems that underpin competitiveness, security, and digital independence. Demand for capacity is accelerating — driven not only by cloud adoption but also by the explosive growth of AI applications, which require far more computing power and energy than traditional digital services.
According to McKinsey, Europe’s data centers consumed about 62 TWh of electricity in 2024. By 2030, demand is expected to more than double to over 150 TWh — roughly 5% of the continent’s total consumption (McKinsey & Company). Meeting this demand will require a rapid buildout of new facilities. But the pace of development is running up against a major constraint: access to sufficient, reliable power. The industry is working to modernize and expand grid capacity while also exploring renewables, low-carbon fuels, and emerging technologies. Ultimately, the success of these strategies will depend not only on securing supply, but on how efficiently that power is used.
This article examines the power constraints facing European data centers and why energy efficiency solutions for data centers, such as waste heat recovery, will be a critical part of the puzzle.
Key Takeaways
- AI-driven demand is straining Europe’s grids — Data center electricity use will more than double by 2030, reaching ~5% of total consumption.
- Renewables can’t cover it all — On-site solar/wind supply only a fraction, while PPAs don’t ensure 24/7 carbon-free power.
- Engines remain unavoidable — Diesel, gas, and dual-fuel engines still provide backup and baseload, but carry cost and carbon challenges.
- Future tech won’t scale fast enough — Hydrogen, batteries, and fuel cells are promising but won’t arrive at scale before 2030.
- Efficiency is critical now and in the future — Climeon’s ORC waste heat recovery is commercially proven. It delivers immediate savings by cutting fuel use and emissions, while remaining essential as data centers transition to renewables and low-carbon fuels.
Exponential Demand Meets Limited Power Supply
The CBRE European Data Centres Figures (Q2 2025) report shows total colocation supply at 4,937 MW, with 792 MW of new capacity expected in 2025. That is roughly the equivalent of adding the electricity demand of several medium-sized cities in a single year.
Across Europe, securing reliable power has become a major bottleneck for new projects. A few examples highlight the scale of the challenge:
- Amsterdam: A moratorium blocks new projects above 70 MW IT load, and hyperscale sites above 80 MW are banned outright. These measures were introduced due to grid congestion and concerns that large facilities consume disproportionate amounts of land and energy compared to their local benefits.
- Dublin: Ireland currently has 14 data centres under construction and 40 more approved (Gardiner), but new projects must meet stricter CRU grid connection rules. Developers are required to prove access to local grid capacity, integrate on-site or renewable generation, and demonstrate demand flexibility to secure approval. These conditions have created a de facto moratorium in Greater Dublin, limiting expansion even as demand continues to rise.
- Europe-wide: ENTSO-E estimates that €800 billion in grid investment is needed by 2050 to keep pace with electricity demand (entsoe.eu). Yet transmission projects unfold over decades, while data center demand is growing year-on-year.
Europe’s data center growth is increasingly constrained by grid congestion and limited ability of power systems to deliver sufficient, reliable electricity where it is needed. This challenge is forcing operators to plan for on-site generation, making efficiency essential to control costs, reduce emissions, and maximize limited power capacity.
Renewables are Essential, but Can’t Do It Alone
Many developers are integrating on-site solar and wind and signing power purchase agreements (PPAs) with renewable energy producers. These strategies are vital for decarbonization, and they will remain central to data centers’ long-term sustainability.
However, local renewables can only cover a fraction of a large facility’s demand:
- A single hyperscale campus may require 30–100 MW of continuous power — enough to supply between 60,000 and 200,000 European homes.
- Rooftop or adjacent solar typically supplies just 1–2% of site demand, while on-site wind is often impractical in urban hubs like Dublin or Amsterdam.
- PPAs ensure clean energy is added to the grid and are vital for decarbonization, but they don’t guarantee a 24/7 carbon-free supply to match the continuous demand of data centers.
Renewables will remain central to data centers’ long-term sustainability, but their limitations — combined with the sheer scale of energy demand — mean operators will still need to fall back on fossil-based generation to ensure reliable supply. That makes it critical to maximize efficiency and minimize fuel consumption wherever engines are required.
The Role of Engines in Reliable Supply
When grid access is limited or delayed, operators rely on engines — diesel, gas, or dual-fuel — to ensure resilience. Engines provide backup, bridge grid delays, and are increasingly used to support baseload supply. More and more, they are being deployed behind the meter (on-site, independent of the public grid), giving operators greater control over their own energy security.
Fuel choice makes a difference, but challenges remain:
- Fossil fuels are the most available and reliable today, but expose operators to carbon costs, emissions regulations, and environmental concerns.
- Low-carbon fuels (such as HVO or biomethane) can significantly reduce net CO₂ emissions. Yet they remain 1.5–3× more expensive than fossil fuels and are in limited supply because they are also needed in transport, heating, and aviation.
For data centers relying on behind-the-meter generation, fossil fuels will remain the primary option in the near term, with biofuels gaining ground gradually where supportive policies and supply chains allow. Regardless of the fuel, engines will remain unavoidable for years to come — and the critical challenge is ensuring that every unit of energy is converted as efficiently as possible.
Few Future Solutions Will Scale Quickly Enough
Technologies such as hydrogen fuel cells, large-scale batteries, and long-duration storage hold great promise. In the long run, they could transform how data centers are powered.
But today, most of these solutions remain at pilot scale, commercially immature, or too costly to deploy widely. Crucially, they will not be available fast enough to meet the steep growth of European data centers in this decade.
This makes immediate, proven efficiency solutions indispensable. Unlike many emerging technologies, efficiency improvements can be deployed today and will remain relevant well into the future — reducing costs, lowering emissions, and making every source of power, from fossil fuels to renewables, go further.
Efficiency First: Powering More with Less
Efficiency is the one strategy that can deliver immediate impact. By reducing waste and maximizing the value of existing energy resources, it cuts emissions, strengthens resilience, and advances sustainability goals — and, crucially, it can be implemented right away.
Most efficiency discussions in the industry focus on PUE (Power Usage Effectiveness), which measures how effectively a facility uses power for IT versus overhead like cooling. But as reliance on behind-the-meter generation grows, efficiency must also be understood in terms of how well on-site energy is converted and used. This is where waste heat recovery adds unique value, ensuring that every litre of fuel and every kilowatt of power delivers maximum benefit.
Climeon’s HeatPower 300, based on low-temperature Organic Rankine Cycle (ORC) technology, addresses this challenge by converting waste heat (75–105°C) from engine cooling systems into clean electricity.
For data center operators, this means:
Lower fuel consumption
Reduced operating costs
Lower carbon intensity of supplemental baseload power
HeatPower improves the sustainability and cost profile of engines, whether they run on fossil fuels today or transition to biofuels tomorrow.
Evolving Potential:
Direct Use of Data Center Heat
Beyond engines, data centers themselves generate large volumes of waste heat from IT equipment. Today, this heat is generally too low in temperature (less than 60 °C) to produce power through ORC systems. But as cooling strategies evolve, operators increasingly aim to run cooling systems at higher temperatures. This approach reduces energy use for chillers, lowers operating costs, and makes it easier to reuse excess heat — whether for district heating or, in time, electricity generation through ORCs as higher-grade waste heat becomes available.
The Path Forward: Smarter, Cleaner, More Resilient
Europe must continue expanding its data center footprint to remain competitive and secure in a digital-first economy. But the pace of growth is outstripping the capacity of grids and renewables to supply power reliably.
Engines will continue to play an inevitable role in ensuring reliable power for data centers, whether running on fossil fuels or gradually shifting to biofuels. Emerging technologies like hydrogen and advanced storage hold promise but will take time to scale.
That makes efficiency a permanent priority. Every litre of fuel saved and every megawatt-hour recovered from waste heat reduces costs, cuts emissions, and strengthens resilience. Commercially proven solutions like Climeon’s HeatPower 300 can be deployed immediately, enhancing the sustainability and economics of on-site power generation. Just as importantly, efficiency will remain essential as the energy mix evolves — ensuring that every fuel, from fossil to renewable, is used to its fullest potential.
The future of data centers will depend on a mix of solutions: renewables, low-carbon fuels, emerging technologies, and efficiency. Waste heat recovery is one piece of that puzzle that can be deployed today and will remain vital in the decades to come.
