Being a first of its kind, the district heating plant in Brønderslev (Denmark) has generated great interest around the world. Last year only, more than a dozen international groups travelled distances to see how this flagship project combines concentrated solar power with a biomass-fired Organic Rankine Cycle for efficient heat and power production. Most recently, a delegation from Japan visited the plant, and senior representatives from Aalborg CSP personally navigated them through the technicalities of the solar energy system.
The solar energy plant is based on the CSP parabolic trough technology consisting of 40 rows of 125m U-shaped mirrors with an aperture area of 26,929m2. These mirrors collect the sunrays throughout the day and reflect them onto a receiver pipe, which sums up to 5 kilometre receiver tubes. This receiver pipe is surrounded by a special glass vacuum tube and inside this runs - only heated by the sun - thermal oil with temperatures up to 330 °C. This high temperature is able to drive an electric turbine to produce electricity, but the flexibility of the system also allows production of lower temperatures for district heating purposes. The solar heating system can thus alternate between providing combined heat and power at peak price periods, or exclusively deliver heat. On sunny days, the solar-thermal system is set to reach 16.6 MWth capacity.The CSP system, developed by Aalborg CSP, has been operational since the end of 2016.
The solar energy system is the first large-scale system in the world to demonstrate how CSP with an integrated energy system design can optimize efficiency of ORC even in areas with less sunshine.
Special thanks to House of Energy for arranging the visit and for the nice picture.