Atmospheric In-cloud Icing Using WRF for an Alpine Wind Power Plant in Norway

Abstract

Troms Kraft have identified a location in Kvænangen, Norway, for a new wind power plant with promising wind resources. However, the site is in an arctic climate with mountainous terrain exposed to severe icing conditions.

Assessments of icing conditions at proposed locations for new wind power plants in areas exposed to icing is crucial to identifying icing related challenges. This paper investigates atmospheric in-cloud icing and thereby identifying conditions affecting the wind turbines at the proposed site. Meteorological parameters are provided from simulations using the Weather Research and Forecasting (WRF) model. Modelled parameters are applied to calculate estimates of the expected annual hours with ice accretion rate exceeding threshold values 10 g/h and 50 g/h for suggested turbine locations. This is done by applying the Makkonen ice accretion model. The WRF model has been run for the whole of 2022.

It is found that model terrain elevation is strongly connected to the calculated ice accretion rate. Because of this, a method for adjusting the icing estimations to differences between model and actual terrain height is conducted.

Analysis of wind patterns at times with modelled meteorological icing shows that ice accretion normally accumulates during winds coming from north-westerly directions. Case studies shows that icing conditions with north-westerly winds induce an increased LWC as a result of orographic lifting.