Fit for the future : Climate action at our sites

"In Bonn, we set ourselves the target of connecting five buildings in an energy-efficient way, merging the heating and cooling systems and significantly expanding photovoltaic capacity. We installed two water-to-water heat pumps, which are supplied from two groundwater wells. These wells act as a source of energy, while also allowing free cooling. To cover peak loads in the heating supply, we also rely on power-to-heat systems. We have also been able to install photovoltaic systems on four out of five roofs. Despite one roof that could not be used, we are achieving a peak output of over 460 kilowatts peak by using more efficient modules. Since 2024, continuous energy monitoring has been in place, which has already revealed optimisation potential that we have been able to implement successfully."

"In Berlin, we had to redesign the originally planned large-scale heat pump due to technical and structural problems. We are now using two smaller heat pumps, which we expect to be able to start using for heating for the first time in 2026/27. Combined with a power-to-heat system, which will be put into operation later, we will enable a heat supply completely free of CO2 emissions within the site. At the same time, we will start installing classic photovoltaic modules on suitable areas of new buildings and flat roofs in 2026. The use of solar roof tiles was originally planned for our listed buildings. However, as there are currently no suitable products available that meet the heritage conservation requirements, we are now also using conventional photovoltaic modules here. As you can see, the project is constantly presenting new challenges, which we solve constructively and creatively. That’s what makes this work so exciting."

"In Frankfurt, we are focusing on three actions: firstly, the cooling towers on the Northern Arcade are being replaced. We want to switch to a technology that minimises water consumption and the associated chemical treatment of water. Secondly, we are striving for maximum expansion of photovoltaic areas. However, not all roof areas can be used due to structural limitations. The expansion is expected to be completed by 2027. Thirdly, we are developing our energy supply concept further. Our target is therefore to be completely free of fossil fuels from 2030 onwards. Adding heat pumps into the mix means the exhaust heat from the cooling system is used almost in its entirety. Air-to-water heat pumps are also used. We cover peaks in demand with district heating. In order to achieve consistent decarbonisation, classic heat generators such as gas and pellet boilers are being dismantled as construction work progresses."