As early as the 1920s, waste heat from the waste incineration plant Josefstrasse in Zurich was successfully used for the first time in 1928 and distributed via district heating pipes. Later, in 1934, Lausanne joined in by using waste heat from the waste incineration plant Tridel and, in the 1940s, Basel with the use of waste heat from the waste incineration plant IWB. This technology provided a cheaper and relatively cleaner substitute for coal for heating large cities.
After the oil crisis in the 1970s, Switzerland started to build up gas networks, while Nordic countries already relied on district heating networks. However, it was not until the 1990s, after the signing of the Kyoto Protocol, that energy sources such as biomass were increasingly used in heating networks in Switzerland. In the meantime, woodchip heating networks are experiencing a boom in Switzerland. They are the most widespread heating technology in terms of numbers (over 600 of about 1,000 known heating networks). Their contribution to heat production is now nearly as large as the waste heat from incineration plants.
Nowadays, low-temperature district heating networks are also increasingly being implemented, which use, e.g., lake water, groundwater, wastewater, or waste heat as sources and are operated at ambient temperature. They currently account for about 2% of the existing heating networks and mostly supply new construction areas.
Within the program Thermal Networks supported by the Swiss Federal Office of Energy, more than 1,000 thermal networks in Switzerland are listed on the map opendata.swiss. Based on data from the association Holzenergie Schweiz, it can be estimated that about 1,200 GWh of district heating from wood-fired systems is supplied by non-members of the VFS (Verband Fernwärme Schweiz).
The heat production, including wood combustion of non-VFS members, amounted to about 8,468 GWh in 2020, corresponding to almost 9% of the total heat demand in Switzerland. The most important primary energy for thermal networks is wood (32.3%), followed by waste heat from waste incineration plants with 31.8%, natural gas (20.7%), renewable heat (8.5%), waste heat from nuclear power plants (4.6%) and fuel oil (2.1%).
The goal is to at least double heat generation by thermal networks by 2050 and thus achieve a share of 25% to 40% of the total heating demand in the long term.
Fernwärme-Statistik 2021 (pdf, in German)
Contact:
Andreas Hurni, Geschäftsführer
Verband Fernwärme Schweiz
E-Mail: andreas.hurni@fernwaerme-schweiz.ch
c/o Ryser Ingenieure AG, Postfach, 3001 Bern
