Data centres combine digitalisation with substantial energy demand. Robust planning therefore considers IT load, power supply, cooling, metering and potential heat customers together. Applicable statutory requirements depend on factors including the size of the facility, commissioning date and the relevant legal conditions. For operators, implementation starts with a transparent assessment of the existing situation and a realistic action plan.
Data centres support digital applications in businesses, hospitals, public administration and many other sectors. As computing requirements grow, IT capacity, utilities and energy demand must be planned together.
PUE is the ratio of a data centre’s total energy use to its IT energy use. For facilities covered by Section 11 of the German Energy Efficiency Act, requirements depend in part on commissioning dates. Facilities commissioned before 1 July 2026 must meet PUE limits of 1.5 from July 2027 and 1.3 from July 2030. A limit of 1.2 generally applies to newer facilities; evidence deadlines, calculation rules and exceptions must also be considered.
Editorially updated on 11 September 2026. Refer to the current Section 11 of the German Energy Efficiency Act.
Great Challenges for the Future
Data centres within the scope of section 11 of Germany's Energy Efficiency Act are subject to differentiated requirements. For data centres commissioned before 1 July 2026, the statutory PUE limits of 1.5 from July 2027 and 1.3 from July 2030 must be taken into account. New data centres from July 2026 are subject to their own requirements for power usage effectiveness and energy reuse. Statutory calculation rules, evidence deadlines and exemptions must be examined for the specific project.
Heat utilisation planning also requires suitable customers, temperature levels and an economically viable connection. This does not imply a blanket heat utilisation percentage for all facilities or a universally mandatory server inlet temperature. Design must bring together operations, technical requirements and applicable regulations.
A Precise Overview Thanks to Sustainability Certification
In order to be prepared for the strict requirements of the future, you need partners who can take a holistic view of the situation. Because an energy-efficient data center is based on different elementary pillars. “It's about keeping an eye on all aspects when planning the tasks to be implemented. It's about the right cooling, the efficiency of the server or the question of location," explains Knopf. "By the way, this applies to the planning of a new data center as well as to the energy-efficient renovation of an existing center."
However, before concepts can be implemented, the current situation must be examined in detail, which is why the individual location is scrutinized. The infrastructure of the entire IT and the utilization of servers are also considered. In addition, sustainable planning also includes the close examination of water as an increasingly valuable and increasingly scarce resource. Based on the sustainability certification, a well thought-out, holistic view of a data center can then be carried out. In this context, for example, in the case of a new building, an assessment is also made of how the data center can later be sustainably dismantled and what use the building could then have.
Working Sustainably with the Elements
“Most data centre operators do not know where they stand on energy efficiency,” explains Martin Vogt, Head of Technology at High Knowledge. Once this assessment of the existing infrastructure is complete, concrete approaches to future improvements can be developed and implemented. High Knowledge has, for example, developed its integrated Blue DC Elements solution, which combines power supply, cooling and waste heat utilisation through project-specific modules. Appropriate advanced technologies can be selected for the local conditions. “In many cases, untapped potential can be identified and substantially lower energy consumption achieved,” says Knopf.
The components connect power supply, cooling and heat reuse. Suitable water circuits can transfer heat from the data centre to neighbouring buildings or heat networks. Technical and economic feasibility depends on factors including temperature, availability over time, heat users and connection costs. Water demand, auxiliary energy and PUE are assessed for the particular facility; the concept alone does not guarantee any specific value.
Choose the best location
Another factor for an energy-efficient data center will be the location in the future. In most cases, such centers are now in the immediate vicinity of Internet hubs such as in Frankfurt am Main. In most cases, however, the waste heat is released directly into the atmosphere – without being used effectively. Knopf: “In the foreseeable future, new plans for data centers will definitely have to break new ground. Since the waste heat is completely released into the environment, as is unfortunately still often the case today, we have several negative effects at the same time. Energy is practically wasted and the waste heat also has a negative effect on the microclimate at the locations of the data centers - and the waste heat has such an enormous potential for meaningful reuse!"
Concepts for economic use see e.g. B. the association with customers in the vicinity. For example, central data centers can be located next to kindergartens or schools, for which the waste heat then serves as a heat source. A connection to the district heating network should also always be planned for a new building. "Especially in today's discussion about high gas and energy prices, hardly anyone talks about the use of waste heat from data centers," notes Knopf. "Here, too, a lot of energy could be used sensibly, but in most cases it still vanishes into thin air."
Conclusion
Planning energy-efficient data centres starts with actual requirements: IT load, utilisation, availability, location and measurement boundaries. Cooling and heat reuse are aligned with these requirements. Blue DC Elements combines technical components in a project-specific concept. Potential energy savings are calculated against a defined baseline and checked during operation. The components alone do not guarantee a particular PUE or climate neutrality.
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