Budarhals Hydroelectric Plant

The Budarhals hydroelectric plant is located in the lower highlands of southern Iceland on the rivers Tungnaa and Kaldakvisl.  Civil construction work on the plant itself began in November 2010 and start-up took place in March, 2014. Power output is 95 MW in two Kaplan turbines with a vertical axis and electricity generation is up to 585 GWh per year. Mannvit was involved in the Budarhals HEP project from the beginning, supervising the geological and hydraulic research, pre-design and feasibility study. Additional involvement included, tender design and tender documentation of penstock and gate equipment, participation in evaluation of tenders and procurement, review of detail design.

Búðarhálsvirkjun - Mannvit.is

Power Plant Details

Water comes from Spordoldulon to the station via 4 km headrace tunnel to station intake. Harnessed discharge is 280 m3/s. The complex includes two steel penstocks where the gross head is approximately 40 m.  A 7 km2 intake reservoir is formed with 1.2 km long earth fill dams with a maximum height of 26 m.  Total reservoir volume is 50 Gl.  The spillway has a maximum discharge capacity of 1500 m3/s. Headrace facilities include a 400 m long canal, tunnel intake, and a 4.0 km long headrace tunnel with a cross sectional area of 140 m2.  The tunnel is supported by rockbolts and fibre reinforced shotcrete as appropriate.

A surge basin is located at the downstream end of the headrace tunnel.  A power intake with trash racks, bulkheads and two roller gates located at the downstream end of the surge basin.  Two 60 m long 5.8 m diameter steel penstocks connect the intake to the above ground powerhouse, where there are two 47.5 MW vertical axis Kaplan turbines with steel spirals.  A short tailrace canal conveys the water from the powerhouse to the existing Sultartangi reservoir.


  • Feasibility study and pre-design
  • Geology
  • Hydraulic, civil, mechanical, electrical, design memorandum

Penstock and gate equipment:

  • Tender design and tender documents
  • Participation in evaluation of tenders and procurement
  • Review of detail design
2x47.5 MW 
65,000 m³ 
4 km 
Headrace tunnel

Budarhals HEP is owned and operated by Landsvirkjun . Landsvirkjun operates 13 hydropower stations, 2 geothermal stations and two wind turbines, in five areas of operation, all over Iceland. Landsvirkjun’s total energy generation for 2013 was 12,843 GWh. Over 85% of the energy is utilised by energy intensive industry and nearly 15% is utilised by smaller companies and for domestic use.