IT & Tech 03.04.2026

6 min Read Time

German data centers consume roughly 20 terawatt-hours (TWh) of electricity per year. By 2030, that figure could exceed 30 TWh – driven primarily by AI workloads. At the same time, the Energy Efficiency Act (EnEfG) is tightening requirements: from July 2027 onward, existing facilities must maintain a Power Usage Effectiveness (PUE) of no more than 1.5. Those who view sustainability solely as a cost factor are missing the point entirely: green data centers are fast becoming a decisive location factor.

The Key Takeaways

The AI Paradox: More Power, More Consumption

The very companies setting ambitious sustainability targets are simultaneously driving massive energy demand through AI workloads. Today, AI-dedicated data centers account for roughly 15 percent of Germany’s installed capacity. Bitkom projects this share will quadruple by 2030. Training and inference for large language models require orders of magnitude more computing power than traditional enterprise workloads.

Germany thus faces a dual challenge. On one hand, demand for computing capacity is growing exponentially – for AI agents in mid-sized enterprises, autonomous systems, and data-intensive industrial processes. On the other, the Energy Efficiency Act imposes strict limits on energy use. Managing both developments simultaneously is the core strategic task for leadership.

„In 2024, Equinix achieved 96 percent renewable energy coverage across its global data center portfolio – for the seventh consecutive year.“
Equinix Sustainability Report 2024

The Energy Efficiency Act: What Takes Effect in 2027

The Energy Efficiency Act (EnEfG), effective since November 2023, establishes binding efficiency standards for data centers in Germany for the first time. Section 11 defines requirements across three areas: energy efficiency (PUE), renewable energy sourcing, and waste heat reuse.

For energy efficiency, the law distinguishes between existing and new facilities. Existing facilities commissioned before July 1, 2026, must achieve a maximum PUE of 1.5 from July 2027, tightening to 1.3 by 2030. New builds commissioned from July 2026 must start with a PUE limit of 1.2. The current EU average stands at 1.6 – meaning a substantial portion of Germany’s existing infrastructure will require retrofitting.

Renewable energy requirements become mandatory in January 2027. Data centers must then cover their entire electricity demand exclusively through non-subsidized renewable sources. This excludes older EEG-subsidized plants and compels operators to secure their own Power Purchase Agreements (PPAs) or direct supply contracts.

Waste heat reuse forms the third pillar. New builds commissioned from July 2026 must repurpose at least ten percent of their waste heat; from 2027, this rises to fifteen percent. An annual reporting obligation also applies: operators must submit their efficiency and energy data electronically to federal authorities by March 31 each year.

windCORES: Computing Inside Wind Turbines

The most unconventional concept originates in Paderborn. windCORES – a subsidiary of WestfalenWIND – operates data centers directly inside the towers of wind turbines. Electricity is consumed at the point of generation, eliminating long-distance transmission and grid fees. Its CO₂ intensity stands at approximately 11 grams per kilowatt-hour (g/kWh), compared with 380 g/kWh for conventional data centers powered by Germany’s average electricity mix.

The advantages extend well beyond environmental accounting. windCORES can deploy new capacity within ten months – versus the typical four years required for traditional data center construction. The windCORES-II concept expands this principle to multi-story data centers housed inside a single wind turbine tower. In December 2025, WestfalenWIND received the German Sustainability Award for this initiative. Over 90 percent of its electricity comes directly from wind power.

NTT DATA Berlin: Waste Heat Heats Residential Neighborhoods

What’s possible with data center waste heat is demonstrated by NTT DATA in Berlin through two pioneering projects. In Marienpark, 2 megawatts (MW) of waste heat supply heating and hot water to over 1,000 buildings. A planned expansion aims to deliver up to 37 MW. The second project, “Das Neue Gartenfeld” in Spandau, launches in early 2025: waste heat from two data centers will feed up to 8 MW of thermal energy into a new residential and commercial district. NTT DATA estimates annual CO₂ savings at around 6,000 metric tons.

According to Bitkom, waste heat from German data centers could annually heat approximately 350,000 apartments – an energy volume equivalent to up to 8 TWh. The potential exists. The bottleneck isn’t technological – it’s infrastructural: district heating networks must reach right up to data center sites, and urban planning must designate heat consumers near data center locations. The EnEfG addresses this challenge – at least partially – by mandating waste heat reuse for all new builds starting in 2026, thereby creating a regulatory incentive to site data centers closer to heat sinks.

Globally, NTT DATA reduced its emissions by 26 percent year-on-year in fiscal year 2023 and increased its share of renewable energy by 15 percent. The company has committed to achieving net-zero emissions for Scope 1 and 2 by 2030. For the German market, the Berlin initiatives are thus not just showcase projects – they mark the beginning of a systematic strategy.

Equinix, T-Systems, Open Telekom Cloud: Who Delivers?

Beyond specialized providers, major operators are also prioritizing sustainability. In 2024, Equinix achieved 96 percent global renewable energy coverage and signed Power Purchase Agreements (PPAs) totaling 370 megawatts this year alone. At its Frankfurt FR13 site, the provider combines LEED certification with 100 percent renewable energy and a “living wall” featuring 17,000 plants.

T-Systems operates its data centers in Biere near Magdeburg with a PUE of 1.3 and LEED Gold certification. Since 2021, the Open Telekom Cloud has run exclusively on renewable energy. T-Systems is also a signatory to the Climate Neutral Data Centre Pact – the European industry’s self-regulatory commitment.

For mid-sized companies purchasing colocation or cloud capacity, these providers offer a tangible lever: selecting a certified, sustainable provider improves their own Scope 3 emissions reporting – without requiring internal infrastructure upgrades. This becomes especially relevant once ERP systems migrate to the cloud and IT infrastructure energy consumption appears explicitly in sustainability reports.

The European Green Data Center Market

The European green data center market was valued at approximately USD 8.9 billion in 2024. It is projected to grow to USD 12.8 billion by 2029 – driven by rising energy costs, CSRD reporting obligations, and regulatory pressure from the EnEfG. Germany is currently Europe’s largest individual market – ahead of the Netherlands and Ireland, which have traditionally served as hub locations.

Frankfurt remains continental Europe’s most important data center location – but it increasingly faces competition from northern European sites offering natural cooling and cheaper renewable energy. For German mid-sized enterprises with latency-sensitive IT systems, Frankfurt remains the top choice. For less time-critical workloads – such as backups, archiving, or batch processing – a Scandinavian location may prove both more economical and more sustainable.

Is PUE Still the Right Metric?

Power Usage Effectiveness (PUE) has been the standard metric for data center efficiency for years. It measures the ratio between total facility energy consumption and the energy actually used by IT equipment. A PUE of 1.0 would be perfect; a PUE of 2.0 means half the energy is lost to cooling, lighting, and infrastructure.

Yet the metric has blind spots. In November 2025, Equinix posed the provocative question: “Is PUE Dead?” The indicator does not measure whether electricity originates from renewable sources. A data center with a PUE of 1.1 running on coal power technically scores better than one with a PUE of 1.4 operating on 100 percent wind energy. Nor does PUE reflect the efficiency of the IT workloads themselves: an over-provisioned, underutilized system carries the same PUE as an optimally sized one.

For mid-sized companies purchasing – not operating – data center capacity, this means: PUE alone is insufficient as a selection criterion. Questions about energy mix, waste heat reuse, and actual utilization are at least equally relevant.

Why Green Data Centers Are Not a Luxury

The economic logic has shifted. Just three years ago, the rule of thumb held: sustainable infrastructure costs more. That remains true for capital expenditures – LEED certification, waste heat systems, and PPAs increase CapEx. But the overall equation flips when three external factors enter the picture.

First: rising energy prices. Investing in efficiency today lowers operational costs tomorrow. A PUE improvement of 0.3 – say, from 1.6 to 1.3 – saves roughly €200,000 per year in electricity costs alone for a data center with a 1-megawatt IT load. Second: regulatory costs. Non-compliance with EnEfG requirements risks fines and loss of access to customer segments that mandate ESG-compliant suppliers. Third: the CSRD compels reporting companies to disclose the carbon footprint of their IT infrastructure. A sustainable provider thus becomes a competitive advantage in supplier evaluations.

For mid-sized enterprises relying on colocation or cloud services – not owning their own data centers – the recommendation is clear: at the next contract renewal, demand sustainability metrics from your provider – and integrate them into your decision-making. The effort is minimal; the strategic impact is substantial.

What Companies Should Do Now

● Review hosting contracts: What PUE does your current provider report? Does it use renewable energy? Is there documented energy reporting? While EnEfG compliance rests with the operator, reputational risk falls squarely on the customer.

● Expand TCO to include CO₂ costs: The “GreenOps” model treats sustainability as a line item in financial statements. Companies subject to – or soon facing – CSRD reporting obligations must quantify their IT carbon footprint regardless.

● Treat waste heat as an asset: For companies operating their own data centers or server rooms: are there nearby heat consumers? Municipal utilities are increasingly open to collaborative partnerships.

● Optimize workloads before upgrading hardware: Before adding new capacity: are existing workloads efficiently sized? Cloud-native architectures, containerization, and automated scaling often reduce energy consumption significantly – even before physical interventions become necessary.

● Update supplier evaluation criteria: Integrate ESG criteria into your supplier evaluation process. Providers investing in sustainability today will likely offer more competitive pricing tomorrow – having already anticipated regulatory costs.

Conclusion: Sustainability Is Becoming a Differentiator

Green IT in data centers is no longer a feel-good topic. The EnEfG sets hard deadlines, the CSRD enforces transparency, and AI workloads drive demand. Anyone connecting these three forces recognizes that sustainable infrastructure is not a cost driver – but a strategic investment in regulatory security, location attractiveness, and lower long-term operating expenses.

Pioneers demonstrate that it works: windCORES at 11 g/kWh, NTT DATA supplying entire neighborhoods with waste heat, Equinix at 96 percent renewables. For mid-sized enterprises, the question is no longer whether Green IT is coming – but whether they’re choosing the right partners.

Frequently Asked Questions

What does the EnEfG require for data centers?

The Energy Efficiency Act (§11) mandates a maximum PUE of 1.5 for existing facilities starting July 2027, tightening to 1.3 by 2030. New builds must meet a PUE of 1.2 from July 2026 onward. Additionally, from 2027, operators must source 100 percent of their electricity from renewables and reuse 10-15 percent of waste heat. Annual energy data reporting is required by March 31.

What does PUE mean – and what’s a good value?

PUE (Power Usage Effectiveness) measures the ratio of a data center’s total energy consumption to the energy delivered to IT equipment. A PUE of 1.0 would be ideal (zero losses); a PUE of 2.0 means half the energy powers cooling and infrastructure. The EU average sits at 1.6. Top-tier providers like AWS achieve 1.15; Google reaches 1.09.

How much electricity do German data centers consume?

In 2024, German data centers consumed roughly 20 TWh – equivalent to 3.9 percent of Germany’s total electricity consumption. Bitkom forecasts growth to over 30 TWh by 2030, driven mainly by AI workloads. Today, AI-dedicated data centers account for 15 percent of installed capacity.

Can data center waste heat really be used for heating?

Yes – and it already is. NTT DATA supplies heating and hot water to over 1,000 buildings in Berlin using data center waste heat. Bitkom estimates this waste heat could annually warm around 350,000 apartments. The challenge lies in infrastructure: district heating networks must extend to data center sites, and heat consumers must be located nearby.

How can a mid-sized enterprise make its IT more sustainable?

Three concrete steps: First, review hosting contracts for PUE, energy mix, and waste heat reuse. Second, optimize your own IT infrastructure for utilization and efficiency – e.g., via containerization and automated scaling. Third, incorporate ESG criteria into supplier evaluations – especially for data center providers.

Header Image Source: Brett Sayles / Pexels