Haraldrud heating centre is one of the nodes in Oslo’s district heating focus and has been in operation since 1982. Part of the base load comes from the City of Oslo’s Waste-to-Energy Agency’s (EGE) nearby waste incineration plant. Hafslund Varme also produces a base load from its own fixed incineration plant which primarily burns sorted waste wood. There are also peak load boilers for the coldest days, or when conditions in the district heating grid result in undercapacity.
The new 56 MW boiler will use pellets and represents an important step on the way to more renewable heat. Wood pellets are ground down into powder, and then blown into the boiler. This is the first boiler of this type of such a size in Norway. The benefits of such boilers is that they can also use other renewable fuels, including wood waste and bio-oil, and can be regulated in the same simple way as an oil boiler. The boiler is extremely flexible and can also be heated using mineral oil as a back-up solution. The new boiler is due to enter full operation in January 2013.
The pellets requirement will be around 40,000 tonnes, which corresponds to more than a third of the total pellets consumption in Norway and a timber consumption of 100,000 cubic metres. A 28-metre-high fuel treatment building with a storage capacity of 2,000 cubic metres of pellets has been constructed for the new plant, where the pellets will be ground down into powder and blown into an interim store before being fed into the incinerators. Consumption is estimated at 13 tonnes per hour at full power, and there is storage capacity for around four days’ consumption.
The establishment has a cost framework of NOK 220 million and will receive NOK 40 million in support from Enova. The Minister of Petroleum and Energy Borten Moe visited the heating centre in December 2011 together with Enova’s CEO, Nils Kristian Nakstad. The Minister has in many speeches highlighted Haraldrud as a reference project for renewable energy.
Following the establishment of the new wood-powder fired-boiler the plant at Haraldrud will have an overall capacity of 267 MW.