Green district heating for Denmark’s second largest city

One of the biggest biomass-fuelled combined heat and power (CHP) stations in the world is located in Denmark’s second largest city, Aarhus. The Studstrup Power Station began to use wood pellets instead of coal as fuel on 10 October, bringing green heating and electricity to the city’s residents and businesses, whilst reducing CO2 emissions by 1 tonne per resident.

One of the biggest CHP plants in Denmark is ready to supply green district heating to Aarhus and the surrounding area, corresponding to the annual heating consumption of 225,000 residents. After over two years of intense work converting the Studstrup Power Station, Lars Christian Lilleholt, the Danish Minister for Energy, Utilities and Climate, inaugurated a power station able to use wood pellets instead of coal as fuel on 10 October.

“I’m delighted that we can now open the new, green Studstrup Power Station, which will be able to supply green district heating to Aarhus and green electricity to the Danish grid. That means a significant contribution to the green revolution, and we’re well on the way to establishing an energy system that is green, independent and economically sustainable,” says Thomas Dalsgaard, Executive Vice President, DONG Energy.

A milestone for Aarhus’ climate targets

The recently completed conversion of Studstrup is the biggest single event in the entire green transformation of Aarhus. The switch from coal to wood pellets at Studstrup not only gives the biggest total CO2 reduction in Aarhus to date, but is also the biggest conversion to green energy sources in Denmark. Kristian Würtz, Alderman for the Department of Technology and Environment in Aarhus Municipality, looks forward to the massive benefits of switching from coal to wood pellets.

“The conversion of Studstrup means that we’ve taken a massive and important step towards fulfilling our ambition becoming CO2-neutral city by 2030. Green heat means that CO2 emissions for everyone in the city can be reduced by one tonne, from six to five tonnes per resident,” he says.

The green conversion of the Studstrup Power Station has provided the City of Aarhus with a tangible force for change.

“Using wood pellets as fuel at Studstrup Power Station will mean a lot in terms of us achieving our climate targets. It gives us the incentive to go further with the green transformation, something we intend to pursue to a greater degree together with residents and businesses,” says Würtz.

The Climate Plan 2016-2020 will set the city’s next climate target, and within the heating area, the new biomass-fuelled CHP station at Lisbjerg will also come on line within the next few months, supplying green heating to Aarhus. Aarhus Municipality will thus bolster green district heating again, ensuring green supply of energy for many years to come, as Studstrup Power Station will supply 50% of the green district heating annually, and the biomass-fuelled CHP at Lisbjerg will supply 20% on an annual basis.

An excellent example

Apart from the now completed switch from coal to wood pellets, the Department of Waste and District Heating in Aarhus built two massive electric boilers at Studstrup Power Plant 18 months ago. They can generate electricity to produce district heating when the Danish wind turbines are running at full capacity, and the electricity prices are low.

“Studstrup Power Station is an excellent example of how we maximise the use of our resources to the benefit of the climate, while ensuring competitive prices for the consumer. We will use both wind power, solar power and biomass and get the various technologies to work together to complement each other in the best way possible,” says Dalsgaard.

The conversion, costing around DKK 1.3 billion, makes Studstrup Power Station one of the biggest biomass-fuelled power stations in the world. In future, it is expected to produce district heating based on biomass for around 106,000 Danish homes as well as green electricity equivalent to the annual consumption of around 230,000 Danish homes.

Photo courtesy of DONG Energy A/S