Sustainability is part of our DNA

Data centers are a challenge in terms of sustainability due to their increasing energy consumption caused by advancing digitalization. The IT capacities of German data centers have grown considerably in recent years. However, there are approaches for improvement. Through the use of efficient server hardware and modern air conditioning technologies, data centers can be operated more energy-efficiently.

Sustainable data centers are characterized by various criteria aimed at minimizing energy consumption and reducing environmental impact. A central indicator for this is the Power Usage Effectiveness (PUE) value, which measures the ratio of the total energy consumption of a data center to the energy actually used for IT equipment. A low PUE value indicates high energy efficiency. The use of renewable energies, such as green electricity from wind, solar, or hydropower, as well as the integration of on-site generation, play an important role. Waste heat utilization and heat recovery systems help to optimize overall energy use.

According to a recent Bitkom study, German data centers consumed about 15.4 billion kilowatt hours (kWh) of electricity in 2021. This significant energy demand reflects the impacts of advancing digitalization and the increasing demand for IT services. The figures highlight the necessity to implement sustainable measures to reduce energy consumption and improve energy efficiency in data centers.

A data center must be cooled to maintain the temperature of IT equipment and infrastructure at an optimal level. Servers and other IT components generate considerable heat during operation. This heat must be dissipated to avoid overheating, which can impair performance or even lead to hardware failures. However, regulating temperature is not the only relevant factor in this context – equally important is the optimal humidity for IT hardware. A properly cooled data center can operate more efficiently, as IT equipment performs better and is less prone to errors at appropriate temperatures. This can also reduce energy consumption, as well-functioning hardware requires less energy for cooling.

The highest energy consumption in data center operations lies mainly in cooling and the operation of IT hardware. Cooling of IT equipment, which must be operated continuously to maintain optimal operating temperatures, accounts for about 30-40% of total energy consumption. Servers, storage devices, and network components that run constantly to process and transmit data consume around 40-50% of the energy. UPS (Uninterruptible Power Supply) systems, which ensure continuous power supply during power outages, contribute about 10-15% to the total energy consumption. Lighting and other infrastructure such as air conditioning and ventilation systems make up the remaining 5-10% of energy consumption.

The sustainability of a data center is evaluated through various metrics and methods. Power Usage Effectiveness (PUE) measures the ratio of total energy consumption in relation to the energy consumption of IT equipment, while Carbon Usage Effectiveness (CUE) assesses the carbon footprint in relation to the energy consumption of IT equipment. Water Usage Effectiveness (WUE) considers water consumption relative to the energy uptake of IT equipment.

Additionally, the use of renewable energy is measured, with a higher proportion contributing to the reduction of the CO2 footprint. Efficiency is also evaluated through energy consumption per computing unit and through sustainability certifications such as LEED or ISO 14001. Life Cycle Assessment (LCA) provides a comprehensive evaluation of a data center's ecological footprint over its entire life cycle. These metrics enable data centers to assess and improve their sustainability.