Abstract: A turbine for production of electric energy in flowing water, comprising a number of shaped foils (5), each foil (5) being attached with a shaft (6) to a supporting structure (3) which is connected to the main shaft (2) of the turbine, and the shaft (6) of each foil (5) being mainly parallel with the main shaft (2). Each foil (5) is equipped with a step motor (8) and encoder (16), and the main shaft (2) is equipped with an encoder (18) and circuit breaker (19); an external measuring device (22) for measuring the speed of the water (11); and a computer (23) comprising a particular computer programme, to obtain that the signals from said encoders (16,18) and said measuring device (22) being processed in said computer (23), to achieve by assistance of said step motors (8) that the angle of a main surface of each foil (5) be individually regulated into a desired direction of attack relative to the direction of said flowing water (11).