Energiekontor AG is a pioneering developer and operator of wind parks with technical innovation as one of its core values. ventodyne GmbH is a young dynamic company specialized in boosting the productivity of wind parks by wind farm control (WFC). Energiekontor and ventodyne have teamed up to bring WFC to the Withernwick wind farm, an onshore park with 13 closely-spaced wind turbines. In this document we report on the results of a six-month test campaign, where two of the Withernwick turbines were equipped with a wake-steering park controller. Toggling the park controller on and off provides clear and quantitative evidence of the effectiveness of this solution. The results also confirm the accuracy with which ventodyne estimated the gain in annual energy production (AEP) prior to field deployment.