The demands placed on modern data centres are growing rapidly. Increasing power densities, new legal requirements and the growing need for energy-efficient solutions pose major challenges for operators. How can data centres (DC) be optimally planned and operated? What role does water cooling play and how does the German Energy Efficiency Act (EnEfG) affect the industry?
In this interview, Peter auf dem Graben, Senior Data Centre Consultant at dc-ce DC-Beratung and expert in data centre planning and operation, provides insights into the most important developments, challenges and strategies for the future. He explains why precise coordination between IT and facility management is crucial, which technologies drive energy efficiency and how operators should respond to increasing power densities.
Mr auf dem Graben, why is the correct planning of power densities in data centres more important today than ever before? What requirements does the law place on operators, particularly with regard to energy consumption, waste heat utilisation and reporting obligations?
Let’s start with the first of the two questions:
The range of power densities of IT infrastructure systems is becoming ever greater. A combination of different power densities poses a greater challenge for DC planning than a homogeneously populated data centre. However, regardless of how the whitespace is later used, the DC infrastructure must be precisely tailored to this in order not to run the risk of violating the legal requirements for data centre operators.
It is true that data centre operators are increasingly being required to comply with legal requirements. Some of these requirements have already been mentioned – they all have the goal of operating data centres efficiently in the long term. This includes, among other things, ensuring that there is a planned ratio of energy consumption between the IT and DC infrastructure, that waste heat from the IT infrastructure is at least partially reused and that a measurement management system is installed in the DC to monitor operations in terms of energy consumption figures. Ultimately, this data must be transferred to the federal government in the DC register.
What impact does the new German Energy Efficiency Act (EnEfG) have on data centres?
In order to operate a data centre efficiently in accordance with the requirements of the German Energy Efficiency Act, the IT infrastructure (required space and power density) and DC infrastructure in the whitespace must be precisely coordinated. The desired efficiency can only be achieved if the intended IT infrastructure is operated with the calculated load. Data centres must therefore be designed ever more precisely for their tasks. This requires greater flexibility in terms of the scalability of a data centre.
How has the increase in power densities in server racks affected the planning, operation and physical infrastructure of data centres?
It is clear to see: The higher the electrical power consumption per rack gets, the more precisely the cooling needs to be planned. We are increasingly coming up against limits where air cooling only works efficiently to a limited extent. However, there are special solutions if air-cooled server systems cannot be dispensed with at present. Otherwise, we are already increasingly focussing on water cooling – or at least planning an infrastructure for it – in order to switch to it with the next generation of IT systems and thus adapt to changing performance requirements.
What role does energy efficiency play in the planning and modernisation of data centres? What specific measures can operators take to make their data centres more sustainable – especially in terms of power supply, cooling and space efficiency?
A common problem is that data centres are built and operated with oversized capacities. As a result, the relationship between the electrical power of the IT infrastructure and the DC infrastructure is out of balance with the desired balance or – to put it more clearly – the balance prescribed by the German Energy Efficiency Act (EnEfG).
Direct water cooling of server systems is an important lever for improving energy efficiency. This offers the great advantage that waste heat can in many cases be directly utilised for other purposes.
