Vojens District Heating

One of the largest solar district heating systems in the world

The consumer-owned district heating company Vojens Fjernvarme is one of the largest solar heating in the world, with 70,000 m2 of collectors, with one of the largest underground thermal storage pit (200 000 m3). The water volume is separated from the district heating water by a heat exchanger and the surface of the water is covered by the liner and an insulated cover and draining system. This storage is operated as an inter-seasonal heat storage, which allows the solar plant to deliver more than half of the annual heat demand of the network. The rest of the heating demand is provided by 3 gas engines, a 10 MW electric boiler, an absorption heat pump, and gas boilers.


One of the biggest hermal pit storage, Vojens District Heating

Technical details:

  • Energy generation: 49 MW at peak effect
  • Energy sources: solar thermal collectors, gas engines, electric boiler, absorption heat pump,
    gas boilers
  • Storage capacity: 200 000 m3
  • Supplied temperature: maximum 95° C