Utility Statkraft plans to install a bypass valve and supplemental turbine-generator at the 130-MW Trollheim hydroelectric project on Norway’s Surna River.
Statkraft said March 7 it plans the modifications at the 1968-vintage project to prevent a reoccurrence of a fish-stranding incident in 2005 caused by an equipment failure at the hydro plant.
High temperatures in a transformer in August 2005 caused the generator to stop, halting the flow of water through the plant for 90 minutes. Fish fry were stranded downstream as a result. The Norwegian National Authority for Investigation and Prosecution of Economic and Environmental Crime (Okokirm) fined Statkraft 1.5 million kroner (US$242,000) and confiscated 2 million kroner (US$322,660) of Statkraft’s profits.
Rather than appeal the penalty, Statkraft said it preferred to use its resources to prevent the problem from happening again. The utility said a review of technical aspects and routines determined the solution is to install a bypass valve that will channel water past the turbine and into the Surna in the event of a stoppage.
Statkraft said it also is preparing an application to install a supplementary turbine-generator at Trollheim that would generate power more efficiently during low flows than the current unit.
Trollheim was Norway’s first hydropower plant to be documented under Norway’s Environmental Product Declaration, a comprehensive statement of the environmental resources consumed or affected in producing a particular product. In 2002, Norske Veritas certified the project as being in accordance with relevant International Standardization Organization (ISO) standards and guidelines of the Nordic Coordinating System for Environmental Product Declaration (NIMBUS).
Located in More og Romsdal County, Trollheim generates an average of 739 gigawatt-hours per year.