Together with the city of Leibnitz, the local district heating utilities, Nahwärme Tillmitsch, Bioenergie Leibnitzerfeld and Biowärme Holler, are pursuing a common goal: to supply district heating to Leibnitz residents with 100% renewable energy. In order to achieve their objectives, a wide ranging set of measures are being implemented to increase the flexibility of the district heating network. The central element is to link up the district heating networks of Nahwärme Tillmitsch and Bioenergie Leibnitzerfeld.
Bi-directional heating network went into operation
The option to exchange heat, either way, between the two networks will ensures an efficient district heating supply that saves resources. A smart control concept was developed for this purpose, under the ThermaFLEX research project, which optimises use of all heat generators in the linked network, to achieve maximum environmental benefit. To facilitate heat exchange across the networks a bidirectional transfer station has been constructed with a transfer capacity of 4 MW. This consists primarily of two heat exchangers (each of 2 MW), with the appropriate ancillary plant (pumps, valves, etc.) and measurement technology. The heat transfer station was installed at the end of 2020 and put into operation in March 2021.
The central element is to link up both of the current district heating networks of Nahwärme Tillmitsch and Bioenergie Leibnitzerfeld. Combining the networks enables two-way exchange of heat and ensures efficient district heating supply that saves resources using renewable energy and simultaneously reducing the use of fossil fuels. To fully exploit the environmental and economic potential of inter-network heat exchange, an appropriate sophisticated network Energy Management System (EMS) has been developed. The EMS uses an intelligent control concept that optimises the use of all heat generators in the entire combined district heating network. This achieves better and more climate-neutral heat supply than with separate operation of the heating networks.
A pre-evaluation study, using historical data to simulate operation for the entire combined district heating network, showed operational cost savings of around 9% and savings in CO2 emissions of some 45% (see Figure 2), due primarily to the significant reduction in use of a gas boiler, amongst other aspects, by combining networks.
More about ThermaFlex
Under the ThermaFLEX project, the AEE – Institute for Sustainable Technologies is conducting work on how to make district heating networks more flexible and efficient and dispense with the use of fossil fuels. In collaboration with 27 project partners, including the Green Tech Cluster, they are providing scientific expertise to support and implement versatile demonstrator projects. One of the demonstrator projects is the Leibnitz district heating network. ThermaFlex is funded by the Climate and Energy Fund and is being implemented under the Green Energy Lab research initiative as part of the Austrian Flagship Energy Region Innovation Campaign.
Participating partners in the demonstrator project – 100% Renewable District Heating Leibnitz:
- AEE – Institute for Sustainable Technologies (AEE INTEC)
- BEST – Bioenergy and Sustainable Technologies GmbH
- Horn Consult – Dr. Wolfgang Horn
- StadtLABOR – Innovationen für urbane Lebensqualität GmbH
- Schneid GmbH
- Alois Haselbacher GmbH
- Nahwärme Tillmitsch GmbH & Co KG
- ENAS Energietechnik und Anlagenbau GmbH
- Bioenergie Leibnitzerfeld GmbH