Landsvirkjun

Búrfell II Power Station

Optimal utilisation of the resource and increased flexibility in operations

With Búrfell Power Station II, the generation output increases by up to 300 GWh per year. This is due to improved utilization of flow to Búrfell Power Station and a decrased efficiency losses, when the load is transferred. The new power station was built underground in the Samsstaðaklif Hill and houses one 100 MW Francis turbine. The 370 m long headrace canal is connected to the existing intake reservoir Bjarnalón and the 2,200 m long tailrace canal discharges the harnessed water into the Fossá River, approx. 1 km downstream from the original Búrfell Station. The harnessed water travels between the headrace and tailrace canals through a 110 m long pressure shaft which connects to the turbine.

100 MW
Hydropower
100 MW
100 MW
100 MW
Installed capacity
1 x 100 MW
1 Francis turbines
300 GWh p.a.
Generation capacity
110 m
Total head
92 m3/s
Maximum flow
June 28, 2018
Brought online

Catchment Area

Thjórsá and Tungnaá Catchment Area

There are seven hydropower stations in the catchment area of Rivers Thjórsá and Tungnaá: Búrfell, Sultartangi, Hrauneyjafoss, Vatnsfell, Sigalda, Búdarháls and now Búrfell II, with combined energy of 1035 MW. Water for all the power stations is provided by three main reservoirs, Thórisvatn, Hágöngulón and Kvíslarveita, along with smaller reservoirs connected with each station.

Lake Thórisvatn, Iceland’s largest lake, is the largest reservoir and an important part of Landsvirkjun’s utility system. All water accumulated in Kvíslarveita and Hágöngulón reservoirs runs through Lake Thórisvatn.

Lake Thórisvatn became a reservoir with the harnessing of River Thjórsá at Búrfell Mountain in 1970-1972. River Kaldakvísl was diverted into the lake at the northern edge of the lake and a controlled outflow constructed at the southern edge.

A canal was dug from the lake and a concrete gate structure built in the canal to manage the flow rate. The canal is named the Vatnsfell Canal, and carries water from Lake Thórisvatn through the Vatnsfell Station into the Krókslón Reservoir above the Sigalda Station, and from there to other stations further down in the catchment area.

Work on the Kvíslaveita Reservoir began in 1980 and was completed in 1997. Kvíslaveita is the collective name for the dams, canals, bottom outlets and gate structures that manage the flow rate from the River Thjórsá and its tributaries into Lake Thórisvatn.

The Háganga Reservoir was constructed in 1997–1999 and covers an area of 27 km2. Its purpose is to increase the efficiency of the catchment area of River Kaldakvísl. During the summer months, water accumulates in the Hágöngulón Reservoir, with very little water flowing down the Kaldakvísl riverbed.

History

The Titan Waterfall Company was founded in 1914, to develop plans for the construction of power stations that would harness the power of Þjórsá River and other Icelandic waterfalls. During the next four years, the company acquired almost all water rights in Þjórsá River and Tungnaá River from Urriðafoss Waterfall and into the highlands of Hrauneyjafoss Waterfall. A Norwegian engineer, named Gotfred Sætermoen, was sent to investigate the Þjórsá area on behalf of the company. The idea was to dam Þjórsá River by Klofaey and direct the river through an open canal in Bjarnarlón reservoir to an intake at Sámsstaðaklif.

The company’s design suggested a powerhouse with 20 turbines at Sámsstaðaklif, between Mt. Búrfell and Sámsstaðamúli. Despite the company’s research on hydrology and hydropower potentials in Iceland, none of its plans came to fruition. The Titan Waterfall Company was dissolved in 1951, when the state of Iceland purchased its water rights.

Landsvirkjun was founded on July 1, 1965, in relation to a power contract with a new aluminum smelter in Straumsvík. To fulfil the contract, Búrfell Power Station was erected. Construction started in June 1966 and three 35 MW turbines started electricity generation in 1969.

In 1972, the capacity was doubled, to 210 MW, and the addition of the mediums above the catchment area created a possibility of expanding the hydropower plant. To that end, it was deemed feasible to build a new power station in Sámsstaðaklif. In 1981, construction began and in 1981-1989 saw the removal of approximately 1.4 million cubic meters of material from the tailrace canal. Subsequently, plans for a new power station were put on hold and the decision made to start construction on other options deemed more feasible at the time. Then, in 1997-1999,Búrfell Power Station was expanded in capacity from 210 MW to 270 MW. Despite the expansion, the possibility remained to further utilize the hydropower flowing through the area. Therefore, the 100 MW Búrfell Power Station II was constructed in 2016-2018, utilizing the flow energy that previously flowed untapped past the older Búrfell Station.

Specifications

Afl og orka
Hönnunarfallhæð 121,5 m
Afl véla, gerð 1 x 100 MW, Francis
Orkugeta 300 GWst/ári
Rennsli
Vatnasvið 6.750 km2
Meðalrennsli 315 m3/s
Virkjað rennsli 92 m3/s
Miðlunarlón
Flatarmál Bjarnalóns 1,18 km2
Miðlunarrými 1,7 GI
Hæsta vatnsborð 247 m y.s.
Lægsta vatnsborð 241 m y.s.
Aðrennslisskurður
Lengd 355 m
Botnhæð 232,5 m y.s.
Botnbreidd 12 m
Fallgöng
Þvermál 5.2 m
Lengd 128,5 m
Straumvölur
Þvermál 4,5 m
Hæð 110 m
Háspennustrengur
Lengd 2,7 km
Spenna 245 kV
Stöðvarhús
Hæð 33 m
Lengd 65 m
Breidd 15,35 m
Frárennslissgöng
Lengd 450 m
Þverskurðarflatarmál 72 km2
Aðkomugöng
Lengd 270 m
Helstu magntölur
Gröftur 1.000.000 m3
Steinsteypa 26.000 m3
ECO steypa (umhverfisvæn steinsteypa) 195 m3
Bendistál 1.164.000 kg
Helstu verktakar
Framkvæmdaeftirlit Landsvirkjun og Mannvit
Hönnun mannvirkja Verkís
Arkitekt VA arkitektar
Landslagsarkitekt Landark
Byggingaverktaki ÍAV Marti Búrfell
Verktaki véla- og rafbúnaðar Andritz Hydro, Þýskaland
Verktaki loka og stálfóðringa DSD Noell, Þýskaland
Framleiðendur háspennustrengs LS Cable, Suður Kóreu
Framleiðendur aflspenna Efacec, Portúgal