NOVELTY - The method involves observing a number of rotations of a rotary drive unit (2) of an energy capturing device (1), and evaluating a derivative of the number of rotations of the drive unit. A load (3) is adjusted based on evaluation of the derivative. A generator (8) is electrically connected to a load circuit (13). A set of distinct regulation modes is governed respectively by a first law and a second law. The drive unit is driven by stream of fluid e.g. water, for transmitting energy to the load.    USE - Method for regulating a wind or tidal energy capturing device e.g. wind turbine or underwater turbine such as vertical axis wind or underwater turbine, that is utilized in an energy producing installation (all claimed) in urban or suburban environment for converting kinetic energy of fluid e.g. air, water and/or vapor, into mechanical and/or electrical energy. Can also be used for regulating a horizontal axis energy capturing device.    ADVANTAGE - The derivative of the number of rotations of the drive unit is evaluated, and the load is adjusted based on evaluation of the derivative, thus improving the performance of the turbine in an efficient, robust and reliable manner irrespective of flow conditions and fluctuations of fluid streams. The method allows the turbine to be operated and implemented in a simple and inexpensive manner. The method allows precise, stable and rapid optimization of operation regime of the turbine. The method enables controlling the turbine at wide operating ranges, and allows a power generation facility to be energy independent.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (1) a regulation module connected with an energy capturing device    (2) a computer program comprising instructions for performing a method for regulating a wind or tidal energy capturing device    (3) a computer readable medium comprising instructions for performing the method for regulating a wind or tidal energy capturing device    (4) an energy producing installation.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of an energy producing installation.    Energy capturing device (1)    Rotary drive unit (2)    Load (3)    Generator (8)    Energy producing installation (10)    Load circuit (13)