The 26,929 mᶟ concentrated solar power (CSP) plant provides the city of Brønderslev with sustainable heating and has been operational since the end of 2016. However, it has not reached its full capacity until now. Currently, the CSP plant supplies heat to Brønderslev’s district heating network but it will soon be contributing to power production when a biomass-fuelled organic rankine cycle (ORC) system goes operational later this year. This combined solution will be the first large-scale system in the world to demonstrate how CSP with an integrated energy system design can optimise efficiency of ORC even in areas with less sunshine.
The 16.6 MWth solar energy plant is based on the CSP parabolic trough technology consisting of 40 rows of 125 metre U-shaped mirrors with an aperture area of 26,929 mᶟ. 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 containing thermal oil. This oil is heated by the sun to temperatures of up to 330°C which in turn enables the plant to drive an electric turbine to produce electricity. 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 development of the world’s first CSP system combined with a biomass-ORC plant is supported by the Danish Government’s Energy Technology Development and Demonstration Programme (EUDP). The subsidy provides substantial support for technology development thereby making the Aalborg CSP solution more competitive in export markets, such as Germany, Austria or Italy that have a well-established district heating infrastructure or an existing base of ORC plants. While the prices of different types of fuel fluctuate, concentrated solar energy proves to be a stable and efficient renewable alternative in Europe.
Danish renewable energy specialist Aalborg CSP was awarded the contract to develop and deliver the solar energy plant by the Danish district heating plant (Brønderslev Forsyning) in February 2016. Construction and installation of the system set records as it took just six months to reach completion.
Image: Aalborg CSP
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