The claimed invention relates to a turbine adapted to extract energy from the velocity of a streaming fluid such as wind, steam, tidal streams and water waves. The invented turbine is arranged with its axis of turbine rotation directed at substantially right angles to the current direction of the streaming fluid and comprising a kind of self-supported blade body which is rotationally symmetric and constructed by rotor blades integrated transversely and supported two by two, allowing the fluid to flow through the turbine with less turbulence compared to other types of turbines equipped with separate rotor blades.