For many, Denmark’s green energy transition is associated with wind or biomass. However, combining several renewable energy technologies for heat and power has recently led to the realization of an ambitious green energy project in the town of Brønderslev – the world's first combined heat and power (CHP) plant to integrate concentrated solar power (CSP) and a biomass boiler while also using Organic Rankine Cycle (ORC) to turn the energy into district heating and electricity.

Utilizing the benefits of these innovative technologies enables the Brønderslev Forsyning district heating plant to achieve record energy efficiency, lower energy prices and a future-proof solution that is no longer dependent on fluctuating fossil fuel prices while reducing fossil carbon dioxide (CO2) emissions.
Part of the new, sustainable CHP facility is an advanced, 26 929 m2 solar energy plant from Aalborg CSP A/S, a Danish developer and supplier of innovative concentrated solar power technologies. This solar-thermal system is based on the concentrated solar power (CSP) technology that has already been producing heat since the end of 2016. With the Organic Rankine Cycle (ORC) and biomass units also going online, it is now ready to contribute to electricity production as well.
We have been honoured to participate in this revolutionary project which is yet another good example of how innovative Danish technologies have the potential to boost energy transition. The era of gas and coal power plants is slowly coming to an end. We are positive that Brønderslev Forsyning’s example is a global trendsetter for markets such as China, where Danish solutions provide proven answers to the country’s future heat and power demands, said Jes Donneborg, Executive Vice President, Aalborg CSP.
Concentrated solar power (CSP) – a flexible energy technology
The CSP technology consists of 40 rows of 125 m U-shaped mirrors that collect the sun rays throughout the day and reflect them onto a receiver pipe. This receiver pipe is surrounded by a special glass vacuum tube and inside this thermal oil is heated solely by the sun to 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 (CHP) at peak price periods, or exclusively deliver heat. On sunny days, the solar-thermal system in Brønderslev is set to reach 16.6 MWth capacity.
The CSP technology is capable of supporting the production of pretty much any energy outputs, be it heat, electricity, cooling, process steam or even desalinated water. That is why our corporate strategy has been focusing on learning from our existing projects and optimizing this technology as a result. Soon, we will be able to deliver the next generation of this type, and reduce the gap between renewable and conventional fuel prices on a global scale, said Jes Donneborg.
The achievement of the world’s first CSP system combined with a biomass-ORC plant was supported by the Danish Government’s Energy Technology Development and Demonstration Programme (EUDP).