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.
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.
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.
|Afl og orka|
|Afl véla, gerð||1 x 100 MW, Francis|
|Virkjað rennsli||92 m3/s|
|Flatarmál Bjarnalóns||1,18 km2|
|Hæsta vatnsborð||247 m y.s.|
|Lægsta vatnsborð||241 m y.s.|
|Botnhæð||232,5 m y.s.|
|ECO steypa (umhverfisvæn steinsteypa)||195 m3|
|Framkvæmdaeftirlit||Landsvirkjun og Mannvit|
|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|