Energy supply for ETH Zurich

The anergy grid beneath the H?nggerberg campus comprises a ground storage system containing hundreds of geothermal probes, as well as a kilometre-long low-temperature ring loop connecting the buildings' energy centres. This allows waste heat sources and sinks to be connected and balanced, marking a significant step towards the efficient use of energy.

Currently, nearly half of the H?nggerberg campus buildings are heated and cooled by the anergy grid and heat pumps.

In contrast, the Zentrum campus is primarily heated using environmentally friendly district heating. A modern cooling network powered by efficient chillers is supplying cold. In future, it is planned to use water from Lake Zurich for this purpose.

There is huge potential for energy savings in electrical lighting at ETH Zurich. While LED lighting is used consistently in new buildings, existing buildings are gradually being converted. In addition, optimised control systems with sensors will further reduce electricity consumption.

Once all these measures have been implemented, they will save around 4,000 MWh of electricity per year.

Many of the buildings at ETH Zurich have complex building services and HVAC systems. Hundreds of heating, cooling and ventilation systems, complete with fans, sensors and controls, are installed throughout the campus.

The energy optimisation team regularly checks and optimises the settings based on energy and operating data to ensure that the buildings are operated with minimum energy consumption, while still meeting user requirements.

ETH Zurich strives to use energy as sparingly as possible for financial and sustainability reasons. At the same time, the Swiss Government has set mandatory energy-saving targets. For over 20 years, ETH has been formulating energy-saving measures and implementing them step by step.

For the current target period up to 2035, ETH has committed to achieving an annual efficiency improvement of 2 percent. These measures will result in additional annual savings of 28,000 MWh from 2035 onwards.

ETH supports various pilot projects (living labs) relating to net-zero technologies.

For instance, the H?nggerberg campus houses a pilot plant for storing hydrogen chemically in iron reactors (see photo).

There are also plans to implement carbon capture and storage (CCS) technology in the H?nggerberg campus's heating plant. This involves capturing CO? emissions produced during combustion directly and storing them long term.

ETH Zurich procures most of its energy with the support of professional partners. It purchases energy in a staggered and forward-looking manner in order to avoid price spikes and ensure security of supply. This process is coordinated by the Engineering and Systems department.

To ensure a fully redundant power supply, it was decided in 2024 that both campuses should be connected to two different medium-voltage substations of the municipal electricity supply via separate lines. Work on this project is underway and is expected to be completed by 2027. This will ensure continuous power supply even if one of the substations fails. The low-voltage transformation will take place directly on campus.

Various ETH sites have emergency diesel generators. These enable the sites to operate in the event of a power failure in the public grid. However, outages of a few seconds may still occur during the switchover in an emergency. Particularly sensitive systems therefore still require an uninterruptible power supply (UPS).

Heating boilers, district heating exchangers, heat pumps and chillers are also partly redundant. This means that there is sufficient capacity to continue normal operations even if individual systems fail.

ETH Zurich is prepared for extraordinary situations. Plans are in place for various scenarios, including power outages, gas or electricity supply shortages, and mandatory rationing. The principle is that teaching and research must take priority.