Tidal harness

Tidal harness is a method of electricity generation achieved by capturing the energy contained in moving water mass due to tides.

Tidal Harness is considered to be a renewable energy source, since the total amount of energy available over time is "Really big".

Interest in Tidal Harness has increased recently, since the inactment of the Kyoto Protocol.

Tidal Harness is really a type of Wave Harness, since a Tide is just a large Wave. The root source of the energy comes from the slow deceleration orbit of the moon around the Earth, and the deceleration of the Earth's rotation.

Currently, large-scale Tidal Harness are considered impossible due to the lack of technology necessary, however there are many small-scale Tidal Harness electricity generators in operation.

La Rance, France 1960 Annapolis Tidal Generating Station, Nova Scotia, 1984 Hammerfest, Norway, 2003

The Hammerfest facility is the first to be connected to an electricity grid.

There are two possible ways to capture Tide energy. The first, older method, is to build a dam called a Barrage on a river or estuary that remains open while the tide is flowing in, and as the tide flows out becomes a Hydroelectric generator. This method is expensive because dam building is expensive, it disrupts the ecosystem in the estuary, and dams have expensive and environmentally destructive silt problems.

A newer method involved placing turbines underwater. This method requires more research to make it practical.

Like Wind Power, selection of location is critical for a Tidal Harness generator. The potential energy contained in a volume of water is E = xMg Where x is the height of the tide, M is the mass of water and g is earth's gravitational force. Therefore, a tidal energy generator must be located in a location with very high-amplitude tides. Suitable locations include parts of the USA, Canada and the UK.

Tidal energy is considered economically infeasable based on current technology. Costs are more than wind power, but are considered less of an eyesore, since turbines are located under the water.

One huge advantage of tidal power is that the energy output is absolutely predictable years in advance, and that a generator can produce energy up to 17 hours per day.

One problem with tidal generators is that it is hard to transport electricity underwater.