In Mürzzuschlag is Austria’s largest ground-mounted solar thermal system

Mürzzuschlag is a town of 8,500 inhabitants in a mountain region between Vienna and Graz. It’s district heating system used to be fired by natural gas and biomass boilers.

The customer, Stadtwerke Mürzzuschlag, wanted to keep its high share of renewable energy in the district heating system at low emissions. And the utility didn’t want to invest on its own, so it preferred a heat-as-a-service contract.

SOLID developed a solution with a 5043 m2 collector field and 3 heat storages of 180 m³ in 2020. In 2023, the plant was expanded to 6850 m² (4800 kW) and 420,000 litres of storage capacity, making it the largest ground-mounted solar thermal plant in Austria. This will further increase natural gas and CO2 savings.