Wind turbines and hydrogenerators can be built for any battery system (12V, 24V, 48V) in case of stand-alone system and for any inverter in case of grid connection. Also their nominal power can be determined according to the application, i.e. depending on the wind or hydraulic potential of the area and the daily demand for electricity. Usually the wind turbine or hydrogenerator is built in the context of a multi-day seminar, so that the future user can participate in the construction, which facilitates the maintenance of the generators. At the same time, a key objective of the project is fulfilled, which is to share knowledge with other people. In this case, the user contributes to the cost of the materials. In case the construction in a seminar is not feasible or desirable then we can do the construction with the corresponding cost.