Investigating the most cost-effective strategies to use active load control in wind turbines of various sizes

Active load control (ALC) is widely considered a key technology for reducing wind turbine loads, thus enabling larger and more reliable rotors. In this work, we investigate the most cost-effective utilization of ALC for wind turbines by exploring the effects of ALC on a range of design variables. In this study, ALC is implemented using a controllable gurney flap (CGF) incorporating a plasma actuator. The five design variables (i.e., the ways we investigate using ALC) in this study include the implementation strategies (retrofit or upscaled), the upscaling design options (power-uprated or load-limited), the ALC operating ranges (in only above rated or across all wind speeds), the turbine sizes (3.4 MW, 10 MW or 15 MW), and the site locations (onshore or offshore). For each of these five design variables, we also evaluate the ALC impact on levelized cost of energy (LCOE) based on the three distinct operating expenditure (OpEx) strategies (fixed OpEx, damage equivalent load (DEL)-weighted OpEx, or capital expenditure (CapEx)-weighted OpEx). The study evaluates the design impacts and cost-effectiveness of ALC through a combined load and component resizing analysis, enabling assessment of capital and operating expenses and LCOE for the above ALC implementation strategies. ALC is widely known to provide fatigue load reduction. To compare different ALC implementations, the analysis involves applying the same rotor upscaling percentage and the same changes in DELs due to ALC across all turbine sizes (3.4 MW, 10 MW, and 15 MW). Results show significant DEL reductions in blade root flapwise moments due to ALC: 11.3 % reduction for retrofit, 6.9 % for power-uprated, and 7.0 % for load-limited designs. Load-limited designs with full-range ALC in all OpEx cases demonstrate the highest LCOE reductions across all turbine sizes. ALC utilized in the full operating range (both Region II and Region III) demonstrates the most cost-effective operating strategy for all turbine configurations. Overall, the evaluation offers a framework to assess ALC’s cost-effectiveness and performance, guiding future turbine designs and retrofits (using ALC) for improved LCOE. • Evaluation of costs (CapEx, OpEx, and LCOE) for active load control (ALC) across a large design space. • Rotor and non-rotor components assessed for resizing and cost implications. • Retrofit designs with ALC show significant fatigue load and cost reductions across all scales. • Load-limited upscaled designs yield high AEP gains and lower CapEx at all scales. • Full operating range ALC proves most economical versus above-rated only ALC operation.