Facts and figures

Where energy-related emissions come from

The ZHAW’s energy-related emissions are derived from heating, electricity and cooling. Heating accounts for the largest share. Accordingly, the reduction achieved since 2017 has been driven primarily by the replacement of fossil-fuel heating systems: where oil and gas heating systems have been replaced by district heating, heat pumps or woodchip heating systems, emissions have fallen significantly. In addition to energy efficiency, the choice of energy source used for heating therefore plays a crucial role.

This is particularly evident in the heating system at the Grüental campus in Wädenswil. Due to an extended heat-pump failure in 2025, additional heating had to be provided using natural gas: gas consumption rose significantly, leading to a sharp increase in heating-related emissions.

Unlike mobility- and resource-related emissions, energy-related emissions barely declined during the pandemic, as buildings need to be heated whether they are fully occupied or empty. Furthermore, the decision on when to replace a heating system is generally beyond the ZHAW’s direct control: the buildings are either owned by the Canton or are leased from it. The ZHAW is working with the Canton to achieve further progress in this area.

Differences between the ZHAW’s locations

The ZHAW occupies more than 70 buildings across seven campuses at its three sites in Winterthur, Zurich and Wädenswil. How much energy a campus consumes depends first and foremost on its size: the more space that needs to be heated, cooled and illuminated, the higher the consumption. Usage patterns are equally as important. Laboratories, workshops and server rooms require many times more energy than offices and classrooms do. And finally, user behaviour also matters, including how rooms are ventilated and heated and whether appliances and lights are switched off when not in use.

What makes up energy consumption and emissions?

The share of renewable energy used for heat generation continues to grow steadily. The average share of renewable energy since 2023 has stood at just under 80 percent. This is primarily due to the declining use of fossil fuels such as natural gas and heating oil. The ZHAW already meets almost all of its electricity needs from renewable sources.