Builds large-scale thermal energy storage, solar thermal, biomass heating plant and high-temperature heat pumps for renewable district heating in Graz.
Wärmespeicher Weitendorf GmbH
Wildon (Headquarters) · Köflach (Biomass Heating Plant) · Weitendorf (Heat Storage)New on Amplifa
About Wärmespeicher Weitendorf GmbH
Wärmespeicher Weitendorf GmbH, headquartered in Wildon (Styria), is implementing large-scale infrastructure for renewable district heating under the project name Sonnen Speicher Süd. The core of the project is the conversion of a quarry in Weitendorf into a heat storage facility with a volume of around 1.5 million cubic metres, whose thermally insulated, floating cover retains seasonally stored heat into spring. Solar fields with a gross collector area of 28 hectares heat water to around 90 degrees; a biomass heating plant with around 49.5 MW fuel heat capacity (BWE Energieservice GmbH, Köflach) raises the temperature to up to 120 degrees as needed for grid feed-in. High-temperature heat pumps with 60 MWth use the storage as a heat source and improve the temperature stratification. Via a transport pipeline approximately 4 km long, the heat is fed into the district heating network of Energie Steiermark and covers about 30% of Graz's district heating demand; around 100,000 tonnes of CO2 are saved annually.
- Site
- Wildon
- Processes
- Solar Thermal, Large-Scale Heat Storage, Biomass Heating Plant, High-Temperature Heat Pumps, District Heating Feed-in via 4 km Transport Pipeline
- Materials
- Large-Scale Heat Storage, Solar Thermal, Biomass Heating Plant, High-Temperature Heat Pumps, Heat Transport Pipeline
- Certificates
- ISO 9001
- Industries
- Renewable Energy, District Heating
- 01
Solar heat generation (28 ha collectors, ~90 °C)
- 02
Seasonal storage in the large-scale heat storage facility in Weitendorf
- 03
Supplementary heating via biomass heating plant (up to 120 °C)
- 04
Heat pump operation for temperature stratification
- 05
Feed-in via 4 km transport pipeline into the Graz district heating network
Plant Technology and Processes
Large-Scale Heat Storage
Conversion of a quarry in Weitendorf into a seasonal heat storage facility with a volume of 1.5 million m³ and a thermally insulated, floating cover.
Solar Thermal
A gross collector area of 28 ha heats water to around 90 degrees for transfer into the storage facility.
Biomass Heating Plant
Around 49.5 MW of fuel heat capacity raises the water temperature to up to 120 degrees as needed for grid feed-in.
High-Temperature Heat Pumps
60 MWth use the storage as a heat source, preferably during electricity surpluses, and optimise the temperature stratification.
Heat Transport Pipeline
A pipeline approximately 4 km long for feeding the heat into the district heating network of Energie Steiermark.
Locations
Wildon
ATHeadquarters of Wärmespeicher Weitendorf GmbH
Köflach
ATProject site of BWE Energieservice GmbH / biomass heating plant
Weitendorf
ATHeat storage facility (quarry)
- Part weight / size
- Storage volume 1.5 million m³
Project Components
Inside the production
Industries
Additional services
Reference customers
Operation and Reliability
The operation of the system comprising storage facility, solar field, biomass heating plant and heat pumps is designed for optimal temperature stratification and efficient use of the collectors. Certificates are currently not documented.
| Evidence | Weitendorf |
|---|---|
| ISO 9001 |
Project History
Sonnen Speicher Süd – project to supply approximately 30% of Graz's district heating with renewable energy; co-financed by the EU's InvestEU Advisory Hub