Virtual heating plant Gleisdorf

THERMAFLEX DEMO PROJECT: Coupling of the wastewater treatment plant with the energy supply

Virtuelles Heizwerk Gleisdorf

This demo is part of the lead-project ThermaFLEX that has been completed successfully. Download the final report.

Objective of the project ThermaFLEX Virtual Heating Plant Gleisdorf

As part of the concept development (individual technologies and system solutions), future heat demand scenarios and strategic development plans were carried out, taking into account all relevant and available local heat sources for the heating network of the town of Gleisdorf. The focus is on the control approach of the “virtual heating plant”, which combines technical measures such as sector coupling with the sewage treatment plant, low-temperature heat utilisation through cascaded heat supply and advanced monitoring and control of the central and decentralised renewable heat supply as innovative elements under one roof.

Approach and methodology of the project ThermaFLEX Virtual Heating Plant Gleisdorf

The sector coupling with the wastewater treatment plant was identified as a key element and is the intended starting measure for the implementation of an “energy hub” at the wastewater treatment plant site. The concept provides approx. 4,320 MWh of thermal energy from the wastewater (heat source for a heat pump) and approx. 864 MWh from the biogas, making a total of approx. 5,200 MWh.

The concept enables full utilisation of the biogas produced now and in the future, and offers another important positive effect in terms of efficient use of resources and circular economy by avoiding the flaring of biogas (surplus). As a result, around 1,368 tonnes of CO2 per year will be saved by linking the sectors. The concept is supported by all relevant stakeholders (City of Gleisdorf, Stadtwerke Gleisdorf, Wastewater Association, etc.) and paves the way for the integration of various further implementation steps that are necessary to cover the constantly growing heat demand of approx. 500 kW/a. The holistic planning of current and future network extensions, supported by energy space planning, is another central element of the demonstration. The new heating system for the town of Gleisdorf will therefore be largely based on renewable energy sources (biomass, solar energy, waste heat from wastewater and biogas).

An expansion and modernisation concept was also developed to optimise the operation of the wastewater treatment plant using membrane distillation (MD). As a first step, an MD pilot plant was installed for demonstration purposes at the end of 2020 in order to obtain important data as a basis for further planning. Optimal process parameters and achievable ammonia recovery rates were investigated, as well as the stability and fouling behaviour of the modules. The quality of the fertiliser produced was also evaluated and possible distribution channels identified. For the first time in Austrian research, a pilot plant for the selective removal of ammonia from the central water of a wastewater treatment plant was investigated for long-term operation.

A new alternative heat supply concept was also developed and installed in an apartment building (10 apartments, floor area: 1,018 m²), which allows cascaded heat utilisation from the return flow only. The heat is supplied via underfloor heating. The maximum required flow temperature of approx. 40°C can be provided by the return flow. The hot water demand is covered by a power2heat application (PV and electric heating).

In general, the implementation of the virtual heating plant control concept in combination with continuous optimisation activities (based on systematic evaluation of operational data and heat consumer analyses) has led to reduced system temperatures of currently 81/49°C, but still has further reduction potential and increases flexibility with regard to sector coupling with the sewage treatment plant. Ongoing measures (primary and secondary measures) to reduce system temperatures and the expansion of the heating network and heat supply capacities in combination with the expansion of the network and the connection of new customers are being implemented on an ongoing basis and have resulted in significant reductions to date.

to the ThermaFLEX lead project

Contact

Joachim Kelz
T: +43 (0)3112 5886-236
E: j.kelz@aee.at

Project key facts

Duration
01.11.2018 - 31.10.2022

funding program
Flagship Region Energy

Project type
Demonstration project

Project budget
2.500.000 €

Project management

AEE - Institut für Nachhaltige Technologien

The following model solutions where being developed in the Virtual heating plant Gleisdorf project:

VIRTUAL HEATING PLANT

Media reports on the project

Kurier: Abwasser als Energiequelle

Wastewater and process water provide heat for buildings: Kurier reports in December 2024 on 'How wastewater can save the future of heat supply! Wastewater could could prove to be an essential element of a sustainable heat supply.

to the article
Energate: Energie aus dem Kanal

There are many advantages to using wastewater as an energy source. In addition to its year-round availability, especially in urban areas with high heating and cooling demand, this mature technology is particularly cost-effective.

to the article
Abwasser-Wärmepumpe

Purified wastewater from the Gleisdorf wastewater treatment plant was used as a heat source and integrated into the district heating network of the Gleisdorf municipal utility. This makes a significant contribution to reducing emissions in the heat transfer process.

Abwasserverband Gleisdorf