To ensure optimal energy utilization, Taars Varmeværk decided to install a combined solar heating system consisting of flat solar-thermal collectors and CSP parabolic trough collectors.


Client:       Taars Varmeværk
Location:    Tårs, Denmark
Status:    Operational
Technology:      CSP + flat panels
Layout:    4,039m2 CSP + 5,972 m
Contract type:    EPC

Combination plant for optimum use of the sun

The system consists of a 4,039m2 CSP plant and a 5,972m2 flat panel field capable of producing 6,082 MWh annually and covers approx. 31% of the annual district heating plant's energy demand, without the use of seasonal storage. The combination of parabolic troughs and flat solar-thermal panels ensures a high performance throughout the day and a large solar heat production, which leads to a significant reduction in the gas consumption. Flat panels have a higher performance at lower temperatures and produce more heat around midday, whereas CSP is most efficient at higher temperatures. The flat panels preheat the water which is thereafter boosted by the CSP technology to achieve the final temperature of 98 °C. By letting the flat solar panels produce at a lower temperature than usually, they provide approx. 20% more.

The first of its kind

The high solar share is achieved by oversizing the plant and using the CSP collectors' control function to avoid problems with overproduction. This is done by utilizing the two existing accumulation tanks, thus avoiding seasonal storage. As the facility in Tårs was the first of its kind in the world, EUDP support was provided for verification and experience sharing.


  • Design and delivery of complete solar collector system (parabolic troughs)
  • Design and delivery of pipping (valves, drain, headers etc.) 
  • Design and delivery of civil works
  •  Mechanical and electrical installation
  • P&I diagrams and control system
  • 3D model
  • Strength and flex calculations
  • Documentation
  • Supervision of installation and commissioning
  • Legalization of the plant


Andreas Zourellis
VP Sales - International
District heating / industrial solar technologies
Phone: +45 50 30 00 25