Exploiting excess heat from a converter station in Endrup, Denmark

This case study is part of a project catalogue produced by ReUseHeat to inspire how to utilize excess heat from urban sources for heating and cooling purposes. The catalogue contains 25 existing or planned projects, 12 of which are Danish and 13 from other European countries.

Description

The Danish Energinet and Dutch TSO TenneT are establishing an international connection between Denmark and the Netherlands called COBRA cable. The HVDC converter station in Endrup near Bramming is expected to deliver excess heat to the local district heating network.

Multiple HVDC converter stations in Denmark connect the Danish electricity grid with surrounding countries and enable international electricity transmission. Near Endrup in Jutland, a converter station has been built, where DC is transported to Eemshaven in the Netherlands through the COBRA cable. The cable has a voltage of 320 kV with a transmission capacity of 700 MW and is expected to be finished and ready for usage in 2019. The converter station will generate surplus heat, which, without energy recovery, is cooled away by fans. The surplus temperature will reach approximately 35 degrees Celsius, and the converter station will have a full load capacity of 3150 kW. Due to the origin of this excess heat, no tax is involved, which benefits the project.

The accessible end-user of excess heat from the converter station is the district heating company Bramming Fjernvarme, located 7 km from Endrup. Bramming Fjernvarme has a decentralized natural gas-powered CHP unit and a district heating network with approximately 2500 households and buildings connected. Multiple options for harvesting the excess heating potential from the converter station exist, but, no real project proposal has been made. One option is to transport low-temperature heat from the converter station to Bramming before heat pumps increase the temperature to district heating network levels around 68 degrees Celsius. A second option is to increase the temperature directly at the converter station and then transport the heat to Bramming. Which option is chosen largely depends on the actual costs and transmission losses. A high-level COP is obtainable due to the converter station's relatively high exit temperature. Estimates suggest a COP factor above 6.0. The costs of establishing the project are currently unknown, but heating production costs will probably be lowered compared to the existing natural gas-fired units.

Endrup, Denmark

ReUseHeat

Expected to be finished in 2019

IVL Swedish Environmental Research Institute

Other case studies from ReUseHeat's project catalogue:

Datacentre supplies local heating in Mäntsälä, Finland

Excess heat from datacentre in Val d’Europe, France

Open District Heating in Stockholm, Sweden

External links:

1. Energinet
2. Dutch TSO TenneT
3. The COBRA cable
4. Bramming Fjernvarme
5. Handbook – 25 cases of urban waste heat recovery