HELIOS – SOLAR DISTRICT HEATING

The HELIOS project uses existing resources and combines innovative, renewable energy generation with modern storage technology. The heat generation plant is directly integrated into the Graz district heating network and demonstrates the advantages of the optimal use of existing local resources (landfill space and landfill gas) on the one hand, while on the other hand, special technical measures are used to demonstrate ecologically innovative alternatives to conventional heat generation. Together with the implementation partner Caverion, SOLID won the tender for the 2nd and 3rd construction phase of the HELIOS project of Energie Graz to expand the collector area from 2,000 m² to 4,000 m² and later to 6,000 m². The heart of the hybrid system is an unpressurized heat storage tank with a usable volume of 2,500 m³, which is filled using solar thermal energy, heat from landfill gas, power-to-heat and other cross-site ecological heat extraction systems. HELIOS cushions power peaks in the district heating network and reduces the use of peak-load boilers – and does so entirely on the basis of renewable energy. Since completion of the 3rd expansion stage to a collector area of 6,000 m², 700 households can now be supplied with heat for heating and hot water. The project was awarded the “Energy Globe Styria Award 2018” and the “Austrian Solar Prize 2018” and is an important part of Graz’s sustainability vision “Heat Supply Graz 2020/2030”.