Green heating to Grenaa

Green sustainable energy

Despite investments of 165m DKK into a new heating plant, district heating consumers in Grenaa can look forward to lower heating prices. The explanation comes in the shape of wood chips.

District heating consumers in Grenaa have more than just one reason for having a big smile on their face: First of all, the city’s district heating is now based on green, sustainable energy. And second, consumers can look forward to lower heating bills since Grenaa Varmeværk in January first fired up the newly built plant, which is exclusively fuelled by wood chips.

There is a ’green’ decision behind the large construction. The heating plant has made a conscious effort to focus on providing consumers with heating from climate and environmentally friendly biomass in the future. At the same time, Grenaa Varmeværk has acquired the newest technology, so the large heating plant can be operated by just four employees as opposed to the 17 that have been there to supply Grenaa with district heating previously. It is due to, among other things, this streamlining that prices are expected to be lowered.

With a joint investment of 165m DKK, the building of the new wood chip plant is one of the largest construction works in Norddjurs Municipality for several decades. Throughout, the project has been hit by unforeseen big problems, since the main supplier of the plant went bankrupt during the process. After that, Grenaa Varmeværk, led by managing director Søren Gertsen, chose to take on the project by itself and finish the plant in collaboration with a subcontractor.

”It cost a summer holiday and some sleepless nights, but I am proud that we have been able to more or less stick to the deadline, and to stay exactly within budget,” says Søren Gertsen.



With the wood chip plant, a new era has in many ways started for Grenaa Varmeværk. For one, the production of heating by using gas oil and waste incineration has now been replaced by biomass, and at the same time, Grenaa Varmeværk will produce all of its heating on its own. Previously, the energy company Verdo has been supplier of the primary part of the heating that Grenaa Varmeværk has then distributed to its approximately 5,500 consumers in Grenaa.

The idea behind ’green’ heating emerged when the contract with Verdo was terminated with a 5-year notice, and in the future, about 95% of the heating from Grenaa Varmeværk will be based on sustainable energy. Primarily biomass – but also heating from the 12,000 square metre solar heating system, which will be expanded with another 18,000 square metres later in 2018, on the large grounds by the wood chip plant.

”Only at absolute peak load on the coldest winter days, will we have to supply with heating from the conventional plants running on gas oil. On the other hand, during summer weeks, we will be able to close down the wood chip plant, and cover demand by pure solar heat,” says Søren Gertsen.



Grenaa Varmeværk has now become a new customer on the market for biomass. 80% of the wood chips, that the Grenaa plant burns, come from Norwegian forests, while 20% come from woods on Djursland.

”We have chosen to use so-called log chips, which is the type that gives the least amount of waste product,” says Søren Gertsen.

The plant expects to use approximately 50,000 tons of wood chips a year, and about 40,000 tons of those will arrive by ship from Norway to the port in Grenaa.

”Grenaa is located perfectly for this type of delivery. From Statkraf in Norway, where all wood chips are delivered from, it only takes 7-8 hours of sailing to Grenaa. This leaves us with really good flexibility.”



He expects 10-15 ship arrivals a year, and the wood chip cargo will at first be stored in a special area on port of Grenaa. From there, the biomass will be shipped continuously to the large silos at Grenaa Varmeværk where it will be stoked directly into the plant’s two ovens. They have an average consumption of 200 tons per day.

Modern technology at the wood chip plant will get the optimal heat out of the fuel. In fact, the plant runs at a 116% efficiency, because the combustion ovens are supplemented with heat pumps, and because heat is harvested from the smoke from the incineration. In fact, so much heat is harvested, that the cleaned smoke is only 20 degrees warm when it leaves the plant’s 55 metre tall chimney.


Video interview with managing director Søren Gertsen, Grenaa Varmeværk: