Shadows cast by wind turbines affect combined solar and wind farms

Combined solar and wind farms, which have the advantage of doubling surface area use and better balancing the load on the energy grid, are on the rise. However, the shadows wind turbines cast on solar panels negates some of these advantages.

Dekker et al. present the first study of the effects of these shadows — both dynamic shadows caused by turbine blades and static shadows from turbine towers — on solar panels, based on measurements rather than model calculations.

“As these combined farms are becoming increasingly important in regions with grid congestion, it is important to know the effect and see if they can be mitigated,” said author Lenneke Slooff. “Our results will give a first guideline for developers in designing their combined solar and wind farms.”

The researchers developed a monitoring system that measures the current, voltage and irradiance levels on millisecond scale needed to capture the effects of the fast-rotating wind turbine blades. With detailed measurements at a combined farm in the Netherlands, the researchers identified effects from the dynamic shadows on inverter performance by for instance disturbance of the Maximum Power Point Tracker (MPPT) of the inverter.

“The effect is strongly affected by the layout of the solar panel system with respect to the electric connections and equipment,” Slooff said. “And similarly of the position of the wind turbines with respect to the solar panel system.”

With more data to comb through, the researchers plan to continue analyzing their initial results. They want to create a calculation tool to predict a farm’s energy output for different system designs and provide data that can improve inverter design.

Source: “Wind turbine dynamic shading: The effects on combined solar and wind farms,” by Nico J. Dekker, Lenneke H. Slooff, Mark Jansen, Gertjan de Graaff, Jaco Hovius, Rudi Jonkman, Jesper Zuurbier, and Jan Pronk, Journal of Renewable and Sustainable Energy (2023). The article can be accessed at https://doi.org/10.1063/5.0176121 .