Energy Impact of Different Solar Tracker Wind Stow Strategies

Kendra Passow, Mudasar Zahoor, Todd Anderson, Kyumin Lee Array Technologies, Albuquerque, NM, United States

Single-axis solar trackers use stow strategies to withstand high-wind events, and “active” and “passive” strategies exist in the industry. With “active” stow, a controller continuously monitors the on-site wind speed and pre-positions the trackers to a safe angle when a wind event is likely. The “passive” stow relies on mechanical components that activate automatically when torque limits are surpassed. Both strategies result in energy losses due to the tracker being out of position temporarily. We simulated the different stow strategies and calculated the energy losses for a utility-scale PV plant. The results indicate that the passive stow strategy may result in significantly lower losses (0.04%-0.07%) than the active stow strategy (2.15%-5.47%) at the two locations considered.