A tidal energy converter has a pivoting lever that moves in response to tidal fluid moving other elements on the converter. The pivoting lever can be operatively coupled with an electricity generator to produce electricity. Namely, the pivoting lever may be coupled to an air source and compress the air to create a compressed air. The compressed air may be used to power an electricity generator. The pivoting lever is moved by fluid that empties from a feed tank to a spill tank. There may be one or more ballast tanks connected to the feed tank and/or the spill tank. Some of the feed tanks work in opposing unison with one of the ballast tanks.

A power generator driving device utilizing tides to form a liquid piston comprises a fixed upside-down lid container, the container mouth is immersed in the seawater and the top end is higher than the highest sea surface while in the flood tide; and, at least one air pipe, having a first end pipe port communicating with the interior of the upside-down lid container and the other second end pipe port being defined above the sea surface, a rotating shaft of the power generator is configured outside the second end pipe port and the second end pipe port faces the windward side or the leeward side of the blade of the rotating shaft. The said configuration enables the seawater inside the upside-down lid container to form a liquid piston, and the liquid piston will gradually rise or fall accompanying with the flood tide or ebb tide of the seawater. Based on the communicating vessel principle, the air inside the upside-down lid container is squeezed by the seawater, such as the liquid piston to be blown out or suck in from the second end pipe port of the air pipe while in flood tide or ebb tide, thereby driving the blade to rotate to enable the power generator to generate electricity.

An electricity generating apparatus has a turbine between two vertical water-tight towers on a floating base that may be managed to attain a buoyancy such that the towers protrude above a water surface and the turbine remains below the water surface. One tower has an upward extending air conduit with an air pump driven by wind vanes at an upper region. The turbine is adapted to be driven by both wave motion and by tide currents, and an air manifold beneath the turbine, fed with air from the air pump, feeds air to aid in turning the turbine, which in turn drives a generator in one of the towers.

A concave hermetic air/brine encapsulating vessel, or cap 10, positioned in the sea at a chosen area according to tidal range. Wherein the open underside of the vessel allows brine/sea water to freely enter or exit the vessel and the tide rises and falls respectively. This rise and fall of the brine within the vessel will result in changes to the air pressure within the vessel, as the air because pressurised as the brine rises, and forms a vacuum with the vessel as the brine falls. These changes in pressure are used to operate a pneumatic actuator 60, via a suitable system of valves 50,52 coupled to the inlets and/or outlets of a pipe couple to a vent 30 on the upper portion of the vessel, or within a plurality of pipes couple to a manifold 40 coupled to the vent 30. Wherein the operation of the pneumatic actuator 60 powers a generator 62 for producing and storing power.

A power generator for generating power from a water flow. The generator has a single blade (1) rotatable through a limited arc about a sweep axis (13) and rotatable through a limited arc about a pitch axis (6) extending along a mid-portion of the blade such the blade is overbalanced. The blade is retainable in two rotary positions in which opposite faces (4) face the flow, It is pushed by the flow in about the sweep axis and is configured to tack about the pitch axis to an opposite rotary position. Passive tacking stops (26) arrest the momentum of the leading edge of the blade and cause the blade to tack. The generator is preferably mounted to extend downwardly from a surface vessel (80).