Aerial view of the University of Konstanz with photovoltaic systems on some roofs.
Eight roofs at the University of Konstanz were equipped with photovoltaic systems in 2018. Now, another 20 roofs with around 14,000 square metres will be added. Image: Frank Nachtwey

Lake water for heating the university

Utilizing thermal energy from Lake Constance and photovoltaic systems on nearly all campus roofs: The University of Konstanz is expanding its renewable energy infrastructure.

In the future, two major projects will make it possible for the University of Konstanz to cover large parts of its energy consumption through renewable energy sources. Thanks to the construction of large heat pumps, more than two thirds of the energy required for heating will be generated from lake water, presumably starting 2027. In addition, the photovoltaic systems on university roofs will be expanded: it is planned that a total of 28 roofs (16,000 square metres) will be equipped with photovoltaic systems by the end of 2025.

"Our aim is to minimize CO2 emissions through the use of renewable energy sources. For us, the project is an important step towards a climate-neutral university", explains Christine Peter, Vice-Rector for Sustainability, Information and Communication Technology (CIO) at the University of Konstanz.

The state of Baden-Württemberg is investing a total of around 30 million euros in the implementation of the large water heat pumps and the expansion of the photovoltaic system. The construction projects were initiated on the basis of Baden-Württemberg's energy and climate protection concept for state-owned properties. They are planned and implemented by "Vermögen und Bau", Konstanz office.

"The heat pump project is one of eight pilot projects in Baden-Württemberg. Combined with one of the largest photovoltaic systems in our area of responsibility, these measures are a significant step towards fulfilling the climate targets of the state of Baden-Württemberg", says Sieglinde Neyer-Bedenk, head of "Vermögen und Bau" in Konstanz.

Lake water for heating
Utilizing lake water to heat the campus: Several large heat pumps will enable the University of Konstanz to cover more than two thirds of its heat requirements through thermal energy from Lake Constance. Taken at a depth of 42 metres at around 6 degrees Celsius, the water will be channelled to the university, where the heat pumps cool it by two to three degrees. The thermal energy extracted in the process is then used to generate heat. The large heat pumps will be installed underground on the campus; the area above will be used for bicycle parking. The pumps are scheduled to be put into operation in 2027.

Utilizing lake water for a sustainable energy cycle is nothing new at the University of Konstanz: since its founding days, water from Lake Constance has been used to cool the university's systems. The existing pipes of the cooling system between the university and Lake Constance will now also be used for heat utilization.

Expansion of the photovoltaic systems on campus roofs
At the same time, the University of Konstanz will significantly expand the photovoltaic (PV) systems on its roofs. In 2018, eight roofs at the university were equipped with PV systems (1,216 modules on around 2,000 square metres). Now, another 20 roofs (around 14,000 square metres) will be added so that PV will be installed on nearly all roofs. This will increase the current capacity of 364 kWp by 1,505 kWp. All of the electricity generated is fed into the university's grid and consumed there.