Búrfell hydropower plant – extension

The existing Búrfell powerstation started generating energy to the national grid in 1969 with six units with total installed capacity of 270 MW and a generation capacity of 2.300 GWh/a. It harnesses the river Þjórsá with a headrace tunnel from the Bjarnalón pond to the powerhouse located in the Thjórsárdalur Valley. The 100 MW extension will be installed with a single turbine unit in a separate underground power station some 2 km east of the existing one. The utilization of the river flow will be substantially improved with the extension since it is estimated that the equivalent of about 410 GWh/a currently passes by the station unutilized. The extension will increase the efficiency in the new and old power plants resulting in an increase in the power plant generation capacity by up to 300 GWh/a. The project will be completed using BIM.

The Búrfell Extension HEP consists of a new underground powerhouse located at the foot of the Sámsstaðaklif depression, with one 100 MW turbine unit harnessing the same head potential and utilizing the same intake pond as the six units in the existing Búrfell Station. A 355 m long headrace canal conveys water from the Bjarnalón pond to the power intake, equipped with trashracks, bulkhead gate and a main wheel gate. A approx. 115 m high vertical pressure shaft, lined with Ø5,2 m embedded steel liner, connects the power intake with the turbine unit located in the underground powerhouse cavern. An approx. 270 m long access tunnel provides access to the powerhouse. The MV power cables are installed in a vertical cable shaft leading to the Transformer building located on the top of the Sámsstaðaklif depression. A 450 m long tailrace tunnel conveys the harnessed water to a approx. 2,2 km long tailrace canal that transfers the water into the Fossá river.