District heating systems

Vestmanna­eyjar district heating

Vestmannaeyjar - Iceland

Verkís services was feasibility studies, conceptual engineering, project planning and cost estimates, preliminary and detail design, civil, structural and mechanical, equipment specifications, tender documents, selection of mechanical and process equipment, construction supervision, start-up and commissioning.

 Sizes: 20 MW
 Project time:  1978 - 1993

Project overview:
The heat central in Westman Islands is operated by HS Veitur hf.  Before the marine electric cable was laid to the island in 1962 all houses were heated with oil boilers, but from that time all new houses were heated with electrical panel heaters. From 1974 to 1988, many houses were supplied by heat harnessed from the cooling lava from the 1973 volcanic eruption.  The district heating network and heat central were constructed in 1980´s, and supplies hot water to all homes on the island.

The heat central is part of Westman Island´s district heating system.  Primary energy is electricity from hydropower and geothermal power stations on the mainland. This is used to produce steam in an electrode boiler for heating of secondary district heating water circulated in a closed-loop distribution network. The electrode boiler´s output is controlled via speed controlled pumps that regulate the water level in the electrode vessel. Heating energy from other sources is also utilised, among these waste heat from a refuse burning plant and two fish processing factories. For reserve heating and emergency back-up, three heavy fuel oil boilers are installed.

The installed power is 20 MW and the current maximum demand is 15 MW. A feasibility study has been carried out for installation of a 3 – 9 MW heat pump that would provide the base load for the heating system. The distribution system is a traditional two pipe system. All pipes are pre- steel pipes insulated with polyurethane in polyethylene casing pipe. The annual energy consumption is 67 GWh, 81% from electricity, 9% from waste, 6% from fish processing factories and 4 % from oil.