Environmentally-friendly district heating for the future

The heating sector is responsible for around half of energy consumption in Vienna, which is why the supply of district heating in Vienna will have a major part to play in the process of decarbonisation. Wien Energie already supplies 380,000 apartments with environmentally-friendly district heating today and operates one of the largest district heating networks in Europe, extending over 1,200 km, enabling us to save 1.5 million tonnes of CO2 every year.

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Background information

District heating already plays a key role in the energy system today and will have to occupy an even more prominent position in the future for renewable energy sources to be integrated into the heating sector. Most of the district heating in Vienna comes from waste incineration and highly efficient cogeneration plants, supply environmentally-friendly heating to around one third of all households in Vienna as part of what is known as the Vienna Model.

  • District heating is environmentally-friendly. In Vienna alone, 1.5 million tonnes of CO2 are already being saved by using efficient and environmentally-friendly technologies.
  • District heating is flexible. A wide range of different methods can be used to supply heat such as heat pumps, geothermal energy, solar thermal energy, power-to-heat, biomass, residual waste and waste heat, making district heating the perfect heating technology for sector coupling.
  • District heating is safe. It does not contain any hazardous substances and there is no need for a combustion process in the buildings that may produce CO2.
  • District heating saves space when installed and is easy for customers to use.

The nearly 1,200 km-long district heating network in Vienna is divided into a primary and a secondary network. The primary network is used to transport significant quantities of heat at high pressure and temperatures of up to 160°C throughout Vienna. The secondary network carries the hot water from the primary network to the individual buildings via converter stations.

Almost the entire district heating in Vienna comes from existing waste heat:

  • Around two thirds of Vienna’s district heating come from highly efficient cogeneration plants, that simultaneously generate electricity and heat, and from industry.
  • About one third of district heating comes from the waste incineration plants Spittelau, Simmeringer Haide, Flötzersteig and Pfaffenau as well as the forest biomass plant in Simmering
  • The remaining one to five percent are provided by district heating plants, which are only used if required.

In the future, the district heating supply will come almost entirely out of renewable energy (such as geothermal energy or green gas).

Aside from having suitable framework conditions, developing renewable sources of heating is the key to expanding the use of environmentally-friendly district heating. Such sources include biomass, green gas, geothermal energy, solar thermal energy or heat pumps. The waste heat from production plants can also be used to make district heating.

Wien Energie has presented a feasibility study setting out the path to achieve a fully decarbonised heating supply by 2050. Wien Energie also provides further insights into the future of heating in its podcast entitled ‘Petajoule’.

Land zoning is a particularly effective way to decarbonise the building sector, which is why Vienna enshrined climate protection zones (including energy plans) with the 2018 amendment to the city’s building regulations. The new regulation pertaining to these zones states that the city council can adopt end-to-end energy concepts for certain areas in Vienna. Only highly efficient alternative heating systems may be used in these areas, including decentralised energy supply systems based on renewable energy sources, micro-cogeneration plants, district heating and heat pumps. Climate protection zones (energy zoning) are to be gradually expanded to cover the whole of Vienna, thereby ensuring an environmentally-friendly supply of heat to the city.

Jürgen Schneider

“The potential for decarbonisation when using district heating is 100 percent, enabling us even in urbanised regions to gradually progress with the process of decarbonisation. This means we are also optimistic that it will be possible to produce district heating entirely without fossil fuels by 2050 at the latest. Another advantage of district heating is that the existing infrastructure can continue to be used in an environmentally-friendly setting.”

Jürgen Schneider, Department Head at the Federal Ministry of Climate Protection (BMK)

Our demands

There is still so much potential when it comes to supplying buildings with district heating. More work is needed and changes to certain framework conditions are required in order to achieve the goal of expanding the supply of highly efficient and renewable district heating.

District heating is the most cost-effective way for heating to help decarbonise cities. Rapid expansion requires a sufficient and secure level of funding from the law on promoting the expansion of heating and cooling pipelines (WKLG) for expanding the district heating network. Local and district heating networks must be developed and expanded, avoiding duplicate gas and district heating infrastructures in doing so. In addition, established investment subsidies from various renewable energy measures such as the Domestic Environmental Support programme (UFI), which can be incorporated into or used in the district heating system, must sufficiently funded.

  • Clear regulatory measures must be taken now to ensure the success of efforts to expand the use of geothermal energy. For the urban heating revolution to succeed, a comprehensive set of subsidies and research initiatives are needed, focusing on the use of renewable district heating produced from geothermal energy. It is also necessary streamline administrative processes as well as accelerating the procedure to search for and extract geothermal energy.
  • Large heat pumps will meet almost one fifth of the demand for district heating in the future. In order to speed up the process of increasing the use of decentralised heat pumps, they also need to be exempted from the flat-rate fees for green electricity as well as other fees and charges for heat pumps that are integrated into heating networks. Another important incentive system are investment subsidies for heat pumps larger than 100 kW and which are integrated into the heating networks.
  • Gas is used in industrial processes, the supply of district heating, mobility and to provide indoor heating and hot water. When it comes to process heat and district heating, there is simply no substitute for gas as an energy source, which means these processes can only be decarbonised by using green gas. Sufficient quantities of so-called green gas must be legally available for use in these essential facilities.

Further information

Your contact person

Tobias Rieder
Tobias Rieder

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