Development, performance and energy trade-off analyses of wind turbine precipitation-reactive control at offshore and onshore sites in Western Europe

Leading edge erosion of wind turbine blades increases Annual Energy Production (AEP) losses and maintenance. Precipitation-Reactive Control (PRC) curtails rotor speed during erosive precipitation events, alleviating erosion but incurring curtailment-induced AEP losses. Using novel methods combining accurate wind and rain measurements and computationally efficient algorithms to select optimal precipitation metrics to steer PRC, the trade-offs of AEP losses for curtailment and erosion at an onshore site in England (Lancaster-Hazelrigg), and a Mediterranean and North Sea offshore site are evaluated. All analyses use time-series of wind speed from cup, sonic or lidar anemometers, and droplet size distributions from laser beam disdrometers. Varying levels of AEP losses for erosion are considered. The assessment at the Mediterranean site, with low erosivity, shows that PRC enables 25+ years of erosion-free operation with a 0.07% curtailment-induced AEP loss, against a 1% loss for moderate erosion. At Lancaster-Hazelrigg, the three-year mean AEP loss of 1.3% considering curtailment and erosion losses is lower than with standard control. The doubled erosion-free life gives a net positive contribution to cost of energy reductions. At the North Sea site, the three-year mean total AEP loss with PRC is higher than without, indicating the need for long-term cost analyses to evaluate PRC viability.