Abstract: A turbine has a first rotating portion configured to rotate about an axis and a second rotating portion configured to rotate about the same axis. The first rotating portion has a plurality of first fluid outlets, and, the second rotating portion has a plurality of second fluid outlets proximate to the first fluid outlets. The outlets are configured so that when a fluid flows out the first fluid outlets, the first rotating portion rotates in a first sense, and the fluid is forced out the second fluid outlets, thereby causing the second rotating portion to rotate in a sense opposite to the first sense. The first and second rotating portions may be connected to drive an electrical generator. The generator and the rotating portions may all be configured to rotate about a single axis, and may all be supported by bearings.