A wind energy system (2, 2.1, 2.2), in particular an offshore wind energy system (2, 2.1, 2.2), comprising: - a first wind turbine apparatus (6, 6.1) and at least one further wind turbine apparatus (6, 6.2), - wherein the wind turbine apparatuses (6, 6.1, 6.2) each have a power detection unit for detecting the actual value of the output power, and - at least one control unit connected to the wind turbine apparatuses (6, 6.1, 6.2) via a communications network, - wherein the first wind turbine apparatus (6, 6.1) comprises at least one operating state detection unit (16a, 16b, 16c, 18a, 20a) for detecting at least one operating parameter of the first wind turbine apparatus (6, 6.1), - wherein the further wind turbine apparatus (6, 6.2) comprises at least one operating state detection unit (16a, 16b, 16c, 18a, 20a) for detecting at least one operating parameter of the further wind turbine apparatus (6, 6.2), - wherein the control unit is configured to determine a performance characteristic for the first wind turbine apparatus (6, 6.1) at least in dependence on the operating parameter of the first wind turbine apparatus (6, 6.1), - wherein the control unit is configured to determine a performance characteristic for the further wind turbine apparatus (6, 6.2) at least in dependence on the operating parameter of the further wind turbine apparatus (6, 6.1), and - wherein the control unit is configured to deactivate at least one wind turbine apparatus (6, 6.1, 6.2) in dependence on the performance characteristics when a power reduction is required, characterized in that - the control unit is configured to generate a model of at least one wind turbine apparatus (6, 6.1, 6.2), - the control unit is configured to simulate at least one power characteristic curve of the wind turbine apparatus (6, 6.1, 6.2) by means of the model, and - the control unit is configured to deactivate at least one wind turbine apparatus (6, 6.1, 6.2) in dependence on the simulation result if a power reduction is required. - a first wind turbine apparatus (6, 6.1) and at least one further wind turbine apparatus (6, 6.2), - wherein the wind turbine apparatuses (6, 6.1, 6.2) each have a power detection unit for detecting the actual value of the output power, and - at least one control unit connected to the wind turbine apparatuses (6, 6.1, 6.2) via a communications network, - wherein the first wind turbine apparatus (6, 6.1) comprises at least one operating state detection unit (16a, 16b, 16c, 18a, 20a) for detecting at least one operating parameter of the first wind turbine apparatus (6, 6.1), - wherein the further wind turbine apparatus (6, 6.2) comprises at least one operating state detection unit (16a, 16b, 16c, 18a, 20a) for detecting at least one operating parameter of the further wind turbine apparatus (6, 6.2), - wherein the control unit is configured to determine a performance characteristic for the first wind turbine apparatus (6, 6.1) at least in dependence on the operating parameter of the first wind turbine apparatus (6, 6.1), - wherein the control unit is configured to determine a performance characteristic for the further wind turbine apparatus (6, 6.2) at least in dependence on the operating parameter of the further wind turbine apparatus (6, 6.1), and - wherein the control unit is configured to deactivate at least one wind turbine apparatus (6, 6.1, 6.2) in dependence on the performance characteristics when a power reduction is required, - the control unit is configured to generate a model of at least one wind turbine apparatus (6, 6.1, 6.2), - the control unit is configured to simulate at least one power characteristic curve of the wind turbine apparatus (6, 6.1, 6.2) by means of the model, and - the control unit is configured to deactivate at least one wind turbine apparatus (6, 6.1, 6.2) in dependence on the simulation result if a power reduction is required.