Largest ground-mounted solar thermal plant in Austria opened!

Styrian flagship project aims to be a role model for the heating transition in Austrian municipalities. The 7,000 square meter solar thermal plant is located in the heart of the Green Energy Lab showcase region and is directly connected to the district heating network in Mürzzuschlag.

Eröffnung Großsolaranlage_SOLID_Vogl_Kelz_Lackner_Jantscher_Rudischer_Hochörtler_Schaffer_Foto: Podesser

(from left) Bernd Vogl, Joachim Kelz, Ursula Lackner, Stephan Jantscher, Karl Rudischer, Thomas Hochörtler, Mathias Schaffer, Photo: Podesser


Mürzzuschlag, September 20, 2023. The largest ground-mounted solar thermal plant in Austria was ceremonially opened today in Mürzzuschlag by Ursula Lackner, Styrian State Councillor for the Environment, and Karl Rudischer, Mayor of Mürzzuschlag, as well as Bernd Vogl, Managing Director of the Climate and Energy Fund, together with Stephan Jantscher, SOLID – Solar Energy Systems, and Thomas Hochörtler, Stadtwerke Mürzzuschlag, as well as representatives of the Green Energy Lab and AEE INTEC. In the future, 7000 m2 of high-performance collectors with 5 megawatts of power will supply around 420 apartments in Mürzzuschlag with environmentally friendly heat from the sun. In the summer months, the heat required in Mürzzuschlag will be generated entirely by solar energy in the future. The large-scale solar plant project in Mürzzuschlag thus makes an important contribution to the ecological heat transition and enables district heating customers to participate in the energy transition. The project is financially supported by the Climate and Energy Fund and the Province of Styria. The plant has already been awarded the Energy Globe Styria for its exemplary function and was also part of the large-scale research project ThermaFLEX, which was awarded the Energy Globe Austria in June 2023.

County Council Ursula Lackner: Important project for the transformation of our energy system.

The importance of the Mürzzuschlager lighthouse project for the transformation of the energy system in the direction of renewable energies and the achievement of the Styrian climate goals is the focus of the Styrian Environment Minister Ursula Lackner in her opening statement: “The energy crisis last winter has once again clearly underlined how fatal the dependence on oil and gas is. Not only for our climate, but also for a secure energy supply in our country. That’s why it’s so important that we manage to phase out fossil fuels. With projects such as the solar thermal plant in Mürzzuschlag, we in Styria are taking major steps towards greater energy independence, climate protection and, ultimately, an affordable and secure energy supply for the people of Styria.” Therefore, the expansion of the large-scale solar plant is financially supported by the province of Styria with 280,000 euros.

SOLID CEO Stephan Jantscher: Roll out proven solar thermal concept to the whole of Austria now!

Solar thermal energy – the use of solar energy to heat water and support heating – has been used successfully in Austria for decades. The solar thermal concept as a substitute for oil and gas is increasingly becoming an international model for a future climate-friendly heating and cooling supply in cities but also in rural areas.
“The first large-scale solar thermal plants have proven to be a cornerstone on the path to an ecological heat transition. The task now is to roll out the concept throughout Austria. In addition to clear legal framework conditions, sufficient subsidies are needed from the federal and state governments. This will give municipalities and energy utilities planning security for the implementation of innovative and sustainable CO2-free alternatives for heating and cooling, such as solar thermal energy,” emphasizes Stephan Jantscher, Managing Director of SOLID Solar Energy Systems.

Mürzzuschlag – e5 municipality focuses on large-scale district heating expansion.
The municipality of Mürzzuschlag received the fourth “e” from Energie Agentur Steiermark in 2021 – only two years after achieving the third “e” (a maximum of 5 e can be achieved). Because: economical and efficient use of energy, the promotion of renewable energy sources such as the large-scale solar plant Mürzzuschlag as well as soft mobility and lived climate protection through numerous projects to reduce CO2 emissions are at the top of the agenda of the city of Mürzzuschlag. “District heating in Mürzzuschlag represents an important factor in increasing sustainability in the city of Mürzzuschlag,” says Mürzzuschlag Mayor Karl Rudischer.
Stadtwerke Mürzzuschlag operates a district heating network with a route length of about 15.3 kilometers, which is operated all year round and supplies not only many private households but also major customers such as the Municipal Sports Center “VIVAX”, the Provincial Care Center, the Provincial Hospital Mürzzuschlag and the Federal School Center Mürzzuschlag. Further expansion projects will be implemented over the next few years. So far, 85% of the heat supplied has already come from regional biomass. The goal of Stadtwerke Mürzzuschlag is to realize an even higher share of renewable energy with simultaneously low emissions for its district heating customers.
“We are aiming to increase the share of renewable energy to close to 100% from 2025, with the solar thermal plant on the Mayerhoferwiese making a significant contribution in the summer months,” DI Thomas Hochörtler of Stadtwerke Mürzzuschlag is pleased to report.

Climate and Energy Fund: Scoring points with intelligent energy transition.
From the program “Solar thermal – large-scale solar plants”, the Climate and Energy Fund supports innovative large-scale solar thermal plants and their solar feed-in into grid-connected heat supplies – the expansion of the large-scale solar plant in Mürzzuschlag specifically with about 470,000 euros, in total more than 1.1 million euros flowed into this showcase project. The aim of the support program is – beyond the implementation of the goals of the domestic climate policy – to support the domestic economy where it can score points in international competition and at the same time to position Austria as a frontrunner for a sustainable energy future.
Bernd Vogl, Managing Director of the Climate and Energy Fund: “The solar thermal plant in Mürzzuschlag is a true lighthouse project not only because it is the largest plant in Austria. It also shows what perfect reuse of infrastructure can look like on technically challenging terrain – a former ski slope. In order to be able to achieve Austria’s committed goals, namely climate neutrality by 2040, it is a matter of understanding different energy sources and storage facilities as integrated systems and advancing them further.”

ThermaFLEX: Solar thermal system as a blueprint for other heating networks throughout Austria.

The large-scale research project ThermaFLEX, led by AEE INTEC, developed different elements and methods to use sustainable energy sources for district heating. The project was carried out as part of the “Green Energy Lab” research initiative, funded by the Climate and Energy Fund and awarded the Energy Globe Austria in June 2023. “The integration of solar thermal combined with corresponding storage concepts is an important step towards decarbonization of heating systems and thus provides a relevant contribution to the achievement of climate targets. The ThermaFLEX demonstrator here in Mürzzuschlag shows on the one hand the successful interaction of applied research & development with regional companies and investors in the implementation phase – on the other hand the high degree of maturity of this technology in combination with the solar potentials give an optimistic outlook regarding the roll-out of such solutions throughout Austria and beyond”, emphasizes Mathias Schaffer, CEO of Green Energy Lab.

Overview Large-scale solar thermal plant in Mürzzuschlag. Photo: Podesser

7,000 m2 large-scale solar thermal plant in Mürzzuschlag. Photo: Podesser

The large-scale solar plant Mayerhoferwiese in Mürzzuschlag

With 7000 square meters of high-performance collectors, the large-scale solar plant in Mürzzuschlag is the largest ground-mounted solar thermal plant in Austria after its expansion. It supplies nearly 420 apartments with environmentally friendly heat, completely replaces boilers running on natural gas in the summer months, and thus saves around 1,000 tons of CO2 per year. Seven heat accumulators with a total volume of 420 m3 act as storage tanks and ensure a solar heat share of approx. 10% over the entire year. The plant and its expansion were planned and built by SOLID Solar Energy Systems and is operated by the specially founded company SolarWärme MZ GmbH, which also supplies the heat to the Mürzzuschlag municipal utility.

About SOLID – Solar Energy Systems

Solar pioneer SOLID – Solar Energy Systems plans and constructs large-scale national and international solar projects in Europe, Asia and North and Central America under the management of Stephan Jantscher. SOLID is the global contact for research on the topic of heat transition and the builder of renowned international lighthouse projects.
Further information:

About Green Energy Lab

Green Energy Lab is the largest innovation laboratory for sustainable energy solutions in Austria and part of the “Vorzeigeregion Energie” of the Climate and Energy Fund. More than 300 participating partners from research, business and the public sector join Wien Energie, EVN, Energie Burgenland and Energie Steiermark in bringing new ideas for the energy future to life.


AEE – Institute for Sustainable Technologies (AEE INTEC) was founded in 1988 and is today one of the leading European institutes of applied research in the field of renewable energy and resource efficiency. The range of R&D projects carried out extends from basic research projects to the implementation of demonstration plants. Further Information:

>> TV report from TV Mürz

From left: Bernd Vogl, Thomas Hochörtler, Karl Rudischer, Ursula Lackner, Mathias Schaffer, Stephan Jantscher. Photo: Podesser

(from left) Bernd Vogl, Thomas Hochörtler, Karl Rudischer, Ursula Lackner, Mathias Schaffer, Stephan Jantscher. Photo: Podesser


Ludwig Fliesser

Communications Manager

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