A method of operating a wind turbine system, the wind turbine system comprising: a convergent section, a divergent section and a wind turbine section located between the convergent section and the divergent section, wherein: the wind turbine section comprises at least one wind turbine and an adjustable turbine-surrounding structure that at least partially surrounds the at least one wind turbine, the turbine-surrounding structure having openings (22, 23) configurable for wind to pass from the convergent section, through the wind turbine section and to the divergent section; and at least one of the convergent and divergent sections comprises adjustable side panels (10, 30) extending away from the wind turbine section; actuators (25, 108, 109, 308, 309) for controlling the configuration of the turbine-surrounding structure and side panels; and a controller for controlling the actuators (25, 108, 109, 308, 309); wherein the method comprises: determining, based upon first wind velocity data, a first configuration of the turbine-surrounding structure and/or side panels (10, 30) for wind to pass through the convergent section and at least one of the openings (22, 23) of the turbine-surrounding structure to the at least one wind turbine; operating, by the controller, at least one of the actuators (25, 108, 109, 308, 309) to configure the turbine-surrounding structure and/or side panels (10, 30) in the first configuration; determining second wind velocity data and measured operating condition data indicative of operating conditions of the wind turbine system whilst the turbine-surrounding structure and/or side panels (10, 30) are in the first configuration; determining, based upon the second wind velocity data and measured operating condition data, a second configuration of the turbine-surrounding structure and/or side panels (10, 30) for wind to pass through the convergent section and at least one of the openings (22, 23) of the turbine-surrounding structure to the at least one wind turbine such that the at least one wind turbine generates power; and operating, by the controller, at least one of the actuators (25, 108, 109, 308, 309) to configure the turbine-surrounding structure and/or side panels (10, 30) in the second configuration. a convergent section, a divergent section and a wind turbine section located between the convergent section and the divergent section, wherein: the wind turbine section comprises at least one wind turbine and an adjustable turbine-surrounding structure that at least partially surrounds the at least one wind turbine, the turbine-surrounding structure having openings (22, 23) configurable for wind to pass from the convergent section, through the wind turbine section and to the divergent section; and at least one of the convergent and divergent sections comprises adjustable side panels (10, 30) extending away from the wind turbine section; the wind turbine section comprises at least one wind turbine and an adjustable turbine-surrounding structure that at least partially surrounds the at least one wind turbine, the turbine-surrounding structure having openings (22, 23) configurable for wind to pass from the convergent section, through the wind turbine section and to the divergent section; and at least one of the convergent and divergent sections comprises adjustable side panels (10, 30) extending away from the wind turbine section; actuators (25, 108, 109, 308, 309) for controlling the configuration of the turbine-surrounding structure and side panels; and a controller for controlling the actuators (25, 108, 109, 308, 309); determining, based upon first wind velocity data, a first configuration of the turbine-surrounding structure and/or side panels (10, 30) for wind to pass through the convergent section and at least one of the openings (22, 23) of the turbine-surrounding structure to the at least one wind turbine; operating, by the controller, at least one of the actuators (25, 108, 109, 308, 309) to configure the turbine-surrounding structure and/or side panels (10, 30) in the first configuration; determining second wind velocity data and measured operating condition data indicative of operating conditions of the wind turbine system whilst the turbine-surrounding structure and/or side panels (10, 30) are in the first configuration; determining, based upon the second wind velocity data and measured operating condition data, a second configuration of the turbine-surrounding structure and/or side panels (10, 30) for wind to pass through the convergent section and at least one of the openings (22, 23) of the turbine-surrounding structure to the at least one wind turbine such that the at least one wind turbine generates power; and operating, by the controller, at least one of the actuators (25, 108, 109, 308, 309) to configure the turbine-surrounding structure and/or side panels (10, 30) in the second configuration.