Abstract: The low head energy in for example a river flow is used to provide electrical energy by directing the water through a duct (70), and by inducing air into the duct to create an air flow which is drawn over an air turbine (76) to excite same, and thereby produce electrical energy. The air can be introduced into the flowing water in the duct by a switching arrangement to ensure that no bubbles or pockets of air travel along with the water, which impairs efficiency. The duct may be in the shape of an anti-gravity course (70) to prevent the bubbles from travelling.

Abstract: The invention provides for the generation of electrical power from low head water, such as the flowing water of rivers or the like, the electrical power is generated by passing the water in sequence over flexible bags or membranes to displace air under the flexible bags or membranes. The displacement of the air is utilized for the driving of a power generator such as an air turbine, and smooth power flow is achieved by diverting air displaced from the underside of one membrane into the cavity under the other membrane. The water flows over the membranes in sequence so that a self oscillating system is set up with the air being displaced back and forth from the cavities, and the displacement air being used to drive the air turbine. Preferably a bi-directional air turbine such as a Wells turbine is used.