The district heating plant in the village of Bedsted (Bedsted Fjernvarme A.m.b.a.) is a consumer owned cooperative with the sole purpose of supplying heat to households in Bedsted.
- Guided tours: Yes
- Open: By appointment
- Booking: 2 work days prior to visit
- Participants: By appointment
- Admittance fee: None
- Parking: Yes
- Public transportation: Train station 500 m from the plant
- Toilet: Yes.
was founded in 1963 at which time heat was produced on the basis of oil. In 1964 142 consumers were connected to the district heating network and in 1966 the plant expanded its capacity with an even larger boiler. The oil fired boiler was later (in 1984) replaced with a coal fired boiler, but the coal-era only lasted for five years in Bedsted. In 1989 the plant reduced its dependency on fossil fuels by converting the coal fired boiler to run on wooden pellets. Today the old oil fired boiler is only activated at peak times or emergency situations. Bedsted Fjernvarme now supplies 450 consumers with environmentally friendly heating which is an almost 100% connection rate. 24 new consumers were connected when a new private nursing home in Bedsted opened in March 2013.
Production costs are kept down by a state of the art distribution grid with well insulated pipelines that significantly reduce loss of heat. Also the flow temperature is adjusted according to time of year since heat loss is less during summer than during winter. This saves energy.
The Wood Fired Boiler
At Bedsted Fjernvarme the primary heat source is wooden pellets. Approximately 2800 tonnes of wooden pellets are delivered to the plant each year where they are unloaded to the grated floor of the storage building. The gateway into the storage is fitted with heavy plastic curtains to stop dust from the pellets being of nuisance to the neighbours. The grated floor allows the pellets to fall onto a conveyor belt situated in the cellar below the storage room. From the conveyor belt the pellets are dumped into a bucket elevator which transports the material into the boiler. Once the water in the boiler is heated it is lead to the district heating pipes via a demand controlled pump which can be supplemented by to manual pumps. The flow temperature is between 74 and 76 degrees Celsius.
The boiler is highly efficient and only a small amount of ashes is left after incineration. The ashes are automatically transported from under the boiler into a container which is emptied three times a year, a rather impressive feat considering the 2800 tonnes of pellets that are processed each year. The boiler has a standard effect of 2,5 MW but if run properly it will yield 2,8 MW. The boiler is the original coal fired boiler from 1986 which was successfully converted to run on wooden pellets in 1989.
Flue Gas Cleaning and Energy Optimization
The boiler is fitted with two cyclone cylinders where the flue gas is cleaned of particles harmful to the environment. The effect of the cyclones is checked by the authorities at unannounced visits. In order to increase the effect of the plant an economizer was installed in the late 90s. The economizer utilizes the remaining heat in the flue gas before it escapes through the chimney. Additionally the economizer is designed to extract heat from the return water optimizing the effect of the plant even more.
Managing the System
At the district heating plant in Bedsted the equipment is looked well after according to the philosophy that there is no need to replace that which works. Therefore the plant is still controlled via the original Metra control system installed in 1963. Spare parts for the system are getting increasingly harder to come by, but by the help of a local radio technician no problems remain unsolved. Furthermore the old system is very robust and repairs are seldom called for. Many other district heating plants have long since shifted to modern computerized SCADA systems, but to Bedsted DHP it is important to sustain a certain level of self-reliance by using equipment that can be repaired on site. Also, installing a new SCADA system would be a large investment for the plant.
Maintaining the district heating system includes maintaining a proper water quality of the water circulating between the plant and the consumers. A water treatment system softens the water by adding salt. Subsequently the water passes through a baghouse filter that filters even very fine impurities from the water preventing pipes and valves from clogging up.
Free Consumer Service
District Heating consumers in Bedsted benefit from free annual service checks including advice on the best way to operate the system. Customers are advised to keep a weekly account of their heat consumption. District heating systems normally run without any operational disturbances, but leaks and malfunctioning valves represent a potential risk of overspending which may not be discovered until the bill is due.
The service check also includes measuring the return water temperature. The return temperature should be as low as possible because low temperatures indicate optimal use of heat in the customer’s household. High return temperatures on the other hand mean that heat has not been sufficiently used prompting the district heating plant to produce more hot water and use more energy. That is why the service check pays off, reducing costs for both the consumers and Bedsted Fjernvarme.
Each year district heating plants in Denmark submit their price lists to the Danish Energy Regulatory Authority. According to the price list of December 2012, district heating from Bedsted Fjernvarme costs DKK 425 per MWh VAT included. This means an annual cost of DKK 9,453 for heating in a standard flat of 75 m2 consuming 15 MWh per year, and an annual cost of DKK 11,886 for heating in a standard single-family house consuming 18.1 MWh per year.
The above mentioned prices are standard prices and in order to calculate the actual price for heating it is necessary to consider the actual heat consumption of a given family and the fixed costs of for example subscription.
For more Danish district heating prices see www.energitilsynet.dk
- Founded 1963 – Renovated in 1996
- 2,5 MW wood pellet fired boiler, Danstoker
- 3,0 MW oil fired boiler, Vølund
- Economizer, Vølund.