District Heating Plant, Nordby-Maarup

Nordby Maarup plant
The Nordby-Maarup plant. Solar array in the fore-
ground. Accumulation tank (round) and boiler house
(with chimney) in the background.

The Nordby-Maarup plant supplies district heating to the villages of Nordby and Maarup. The plant burns wood chips, and it has an array of solar panels as a supplementary source of heat. In fact, during the summer-period the solar array supplies all energy in extended periods of time. The energy company NRGi owns and operates the plant. According to the original master plan, this plant was to be the last to be built. But a local group of citizens managed to accelerate the project and finish it five years before the final deadline.


After a citizens meeting, a local work group asks the energy company NRGi to design a district heating plant. Meanwhile the work group walks from door to door to talk to the potential consumers, and the group is highly active in all respects.

NRGi submits the first project proposal end of November 1999.

After negotiations — with the national authority (the Danish Energy Agency, da: Energistyrelsen), the municipality, and the Samso Energy Company — the energy company NRGi submits its second revised proposal in October 2000.

The municipality pre-approves the proposal, then the Danish Energy Agency approves. The municipality gives its final approvement on the following conditions: that all municipal buildings connect to the distribution net, that at least 70% of all houses with own central heating agree to connect, that all new buildings are obliged to connect, and that the owner tries to utilize local energy crops such as elephant grass. Start-up of wood chip boiler in November.

Start-up of solar array in April.


Power rating 1.4 MW
Heat generators 0.9 MW wood chip boiler with flue gas heat exchanger (Weiss) + 2.2 MW solar collector array (ARCON)
Auxiliary generator for reserve and peak load 1.4 MW oil burner, delivers about 4% of the energy
Hot water accumulation tank 800 cubic meters
Fuel 3 200 MWH/year wood chip + 96 MWH/year oil at design capacity.
Storage Wood chip: 7 days of peak load. Oil: 14 days of peak load.
Design capacity 90% of the potential heat consumption
Potential heat consumption 3.7 MWH/year
Initial consumer connections 72% of the potential heat consumption
Production by solar array 1 090 MWH/year or 430 KWH/sq m,
Solar array coverage 21% of the energy (May 2002 - Apr 2003)
Buildings - One boiler room with 130 cubic meters of chip storage,
- one accumulation tank, diameter 8.5 m and 300 mm insulation,
- 2 500 square meters of solar panels, and
- a 25 000 liter oil tank underground
Solar array 20 rows of 10 panels at 12.5 sq meters, bearing 167 degrees, inclination 40 degrees. Max power rating: 2 200 kW.
Fuel savings 1 000 MWH/year compared to individual oil boilers
Fuel source Primarily from the woods of Brattingsborg at Samso
Owner NRGi
Construction costs 20.4 mill DKK (2.7 mill EUR)
Subsidies 9 mill DKK (1.2 mill EUR) from the Danish Energy Agency
Construction cost of solar array 4.7 mill DKK (0.63 mill EUR)
Calculated consumer price of solar energy 0.29 DKK/KWH or 0.15 DKK/KWH with subsidies
Consumers connected 180 households corresponding to 80%
Consumer's annual fee (2010) 2817 DKK/year (376 EUR/year), VAT tax (25%) included
Consumer's heat price (2010) 755 DKK/MWH (101 EUR/MWH), VAT tax (25%) included
Consumer's connection fee 25 000 DKK + 1 200 DKK/m piping (3 330 EUR + 160 EUR/m)

Created by jj. Last Modification: Thursday 16 September 2010 21:10:32 CEST by jj.