Conclusions o A significant proportion of the tidal and marine current energy resource is to be found on the east coast of Ireland. The resource on the west coast is concentrated in the Shannon Estuary.

It is estimated that there is some 615 terawatt-hour (TWh) per year of harvestable energy from tidal streams, ocean currents, and riverine currents and marine hydrokinetic power systems can harvest that energy. This is equivalent to about twenty times the Republic’s annual electricity usage.

The main disadvantages of tidal power are that there are limited installation sites, it is expensive, the turbines can impact the surrounding ecosystem, and the power produced does not always match up with peak energy demand.

Ireland has one of the best resources in Europe for harnessing offshore wind energy. The east coast of Ireland has sufficiently shallow water depths to allow for fixed foundations turbines, while floating structure may be more appropriate for many sites off the south, west and north-west coasts.

A tidal energy generator using tidal lagoons would function much like a barrage. Unlike barrages, however, tidal lagoons can be constructed along the natural coastline. A tidal lagoon power plant could also generate continuous power. The turbines work as the lagoon is filling and emptying.

In simple terms, a tidal energy works via a turbine works like a wind turbine, with blades rotating 12-to-18 times a minute depending on tide strength. The turbine is connected to a gearbox that turns a generator, creating electricity.

South Korea
With total installed tidal power capacity of 511MW, South Korea is leading the way globally, according to the information provided by National Energy Board of Canada. South Korea is followed by France with 246MW, and the United Kingdom with 139MW.

The largest facility is the Sihwa Lake Tidal Power Station in South Korea. The United States has no tidal plants and only a few sites where tidal energy could be produced at a reasonable price. China, France, England, Canada, and Russia have much more potential to use this type of energy.

Difference between tidal energy and wave energy Tides are the rise and fall of the ocean caused by the gravitational pull of the moon and sun on the earth while waves are the wind energy moving across the surface of the ocean thereby making waves much easier to measure as when compared to tides.

But it turns out that NI is home to one of Earth’s best sites for harnessing tidal energy – specifically, Strangford Lough. The world’s first tidal power station was constructed here in 2007. Tidal energy involves harnessing the predictable, and powerful, surge of water that happens twice a day with high and low tides.

The sun and moon’s gravitational pull and the predictability of the tides make tidal energy an inexhaustible form of renewable energy which has been used in various forms since the Roman times. When the high tide makes its way to the shoreline, water is trapped in reservoirs or river estuaries and stored behind dams or barrages.

The gross energy content of tidal and marine currents in the zone between the 10m depth contour and the 12 nautical mile territorial limit is referred to as the Theoretical Resource. The theoretical tidal energy resource has been determined using computational modelling of current flows around Ireland.

The coast off the west of Ireland has been identified as one of the major potential sites worldwide for wave energy. Potential of up to 70 GW of ocean energy opportunity within 100km of the Irish coastline (offshore wind, wave and tidal).