18/11/2019

Hörn delivered presentations about Laxá III

  • LaxáIII

Hörn Hrafnsdóttir, Water Resources Engineer at Verkís, has recently delivered two presentations about Laxá Power Plant III. The first presentation was at HYDRO 2019 in Portugal and the second one at NNICOLD 2019 in Norway.

The presentations are based on a field of study which Hörn wrote collaboratively with Guðmundur R. Stefánsson, Einar Erlingsson, Guðmundur Pétursson og Guðmundur Björnsson, engineers at Landsvirkjun og Landsvirkjun Power. 

Horn_hrafnsdottir_litur

The Laxá Power Plant III from 1973 (14 MW, discharge 44 m³/s) is a run of the river plant that had severe operational and abrasional problems due to ice and sediment transport. In 2016/17 the dam and intake were rebuilt to reduce the operational problems. The changes, designed by Verkís Consulting Engineers, include a new outer intake with ice skimming spillway on top and two small sediment traps for flushing sediment (sand up to relatively large stones) past the power station's waterways.

The goal was to divert both ice and sediment, back to the river downstream of the dam. The plant started again in March 2017. The experience after two years in operation is good, even though the ice skimming has not been fully functioning and the gravel excluder has been inoperational during part of both winters. No operational problems affecting the power production have occurred due to ice and sediment transport around the intake area. Some sediment still passes through the turbine but very little compared to before and wear on mechanical parts seems normal.

Verkís gave advice and designed the changes that were undertaken.

Laxá III - A new intake and changes to the dam