First Electricity, Now Heat Transition

The backlog of renovation work at universities in Berlin is something we are all familiar with. However, the funding required for energy renovation is particularly restricted. “Would it not make sense to view the costs and benefits of individual measures in terms of the entire campus?” This was the question a team of researchers at Technische Universität Berlin asked itself before going on to develop a software tool for this purpose. The software calculates exactly which measures at which buildings have the greatest energy-saving potential for the entire Charlottenburg campus and at the least possible cost.

A new software tool calculates how to achieve the federal government´s goal of heat transition on the TU Berlin/Berlin University of Arts (UdK) campus.

TU Berlin´s computer center is fairly bursting with energy. The servers produce 4.7 gigawatt hours of thermal discharge each year. The annual thermal discharge of the cooling devices in the Main Building is even greater at 5.8 gigawatt hours. “This total of 11.5 gigawatt hours (the equivalent of the heating requirements of some 50 typical Berlin apartment buildings from the late nineteenth/early twentieth centuries) is enough to provide 20 percent of the annual heating requirements of TU Berlin and the Berlin University of the Arts,” says Professor Martin Kriegel, head of the Chair of Building Energy Systems. This finding was the result of an analysis conducted together with the Chair for Energy Conversion Technology, led by Professor Felix Ziegler, as part of a research project whose goal was to examine ways to create a more energy-efficient campus. Up until now, this energy has simply gone unused.

We need a heat transition

Changes need to be made. The team of researchers want to develop a plan by 2023 to meet the federal government´s energy transition target for the heating of buildings (to use renewable energies to meet 80 percent of primary demand by 2050) on the TU Berlin/ Universität der Künste (UdK) campus. Currently only 10 percent of the energy used to heat buildings in Germany comes from renewable sources.

One hundred percent of the electricity used by TU Berlin is already gained from renewable sources. However, it is a very different story concerning the energy used for heat supply, in other words the heating and cooling of rooms and labs. “We have fully achieved electricity transition at TU Berlin; now we need to do the same for heat,” says Kriegel. To achieve this, thermal discharge and renewable heating are to be used, deployed and cached on the campus.

From scientific analysis to practical implementation

During the first phase of the project from 2016 to 2018, the researchers analyzed all 49 buildings of the two universities (TUB and UdK) in terms of their energy consumption and developed 1000 individual measures to achieve the goal of energy transition. These include renovating the facades, roofs and windows as well as the use of thermal discharge, solar energy and heat recovery. It is common knowledge that Berlin´s finances are stretched and given that the universities receive money from the city to finance building work, the researchers involved wish to achieve heat transition at as little cost as possible. This benefit-cost approach led to the development of a new method: “We abandoned the idea of renovating every single building in terms of energy, which would have been complete financial madness, and decided instead to view the entire TU Berlin/UdK complex as a kind of holistic organism and coordinate the energy measures for the buildings in such a way as to achieve the goal of heat transition. In doing so, we are shifting the energy audit from the individual buildings to the entire complex,” Kriegel explains.  The teams have developed a software tool to correlate the 1000 individual measures with the buildings. By doing so they can find out which measures have the biggest energy-saving potential for which buildings at the least cost.

Wärmerückgewinnung heißt das Zauberwort

This method is to be introduced as part of the campus development program, which seeks to clear the backlog of renovation work at TU Berlin and UdK over the next 10 to 20 years. The team of researchers is making itself available to advise on which decisions need to be taken in terms of energy throughout the renovation work. “The Eugen Paul Wigner building at TU Berlin, for example, has the largest consumption of energy and heat of all the 49 buildings. Using our tool, we were able to determine that renovating the windows would result in negligible energy savings but would involve high costs. However, installing a heat recovery facility would halve the annual energy consumption, with the measure paying for itself within a year,” says Martin Kriegel. Both Physics Buildings, the Chemistry Building and the Physical Chemistry and L Buildings on Müller-Breslau-Straße all use a lot of ventilation engineering and would also therefore benefit greatly from the installation of heat recovery facilities. The combined energy-saving potential would amount to approximately 10 gigawatt hours per year.

The project is being funded with five million euros by the Federal Ministry for Economic Affairs and Energy. Further cooperation partners in the project are Professor Claus Steffan, Chair of Building Engineering (TU Berlin), Professor Christoph Nytsch-Geusen, Chair of Supply Planning and Supply Engineering (UdK), EON Energy Solutions and Vattenfall Berlin.