Tidal Energy: The World's Next Renewable Powerhouse?

(3Bl Media/Justmeans) - In a windy, protected sound off the north coast of Scotland ,a power generator is being built to harness energy from Scotland’s most abundant resource: the ocean. The generator is owned by MeyGen, majority-owned by Atlantis Resources, LTD, and is slated to be the largest tidal array in the world, with the capacity to power as many as 175,000 homes. Plans are for 269 turbines to churn the water below the ocean’s surface, in what experts say surprisingly, is the most stable environment in which to generate electricity.

Some 350 miles south, on the western coast of Ireland, the U.S.-based Ocean Renewable Power Company is working on launching its first U.K. tidal energy array. It won’t be as big as MeyGen, but its endeavor will help add push to the U.K.’s investments in hydroelectric energy.

Wave and tidal energy is becoming an increasing focus around the world, as governments and power companies realize that there is a potential for developing a power source from the natural gravitational pull of the sun – a concept that has been used for more than a thousand years. Historians point out that rising and falling tides and the power of fresh water used as early as 8th century to facilitate essential operations like milling grain.

Today, tidal power operations are considerably more sophisticated and have the potential to generate significantly more power. In the seaside city of Cardiff, a 14-mile seawall is expected to serve as a tidal energy generator, using the rise and fall of Wales’ ocean tides to power homes.   It is one of six different lagoons across the U.K., that would generate as much as eight percent of the U.K.’s energy for the next 120 years.

According to TidalEnergyUK, tidal barrages, like Cardiff’s proposed sea wall, offer distinct advantages in seaside cities and river communities where the environment can be adapted to energy conservation. Where tidal stream systems can be placed off the coast in unpopulated areas, the tidal barrages can be built as features within coastal and fresh-water communities.  An 11-mile-long barrage proposed for the environmentally sensitive area called the Wash, in Northwest England, for example, would use the ebb and flow of a small, remote inlet frequented by waterfowl.

Tidal stream systems are favored in many areas because they are less expensive  to implement than tidal barrages. The cost of the 14-mile seawall is estimated to be in excess of $9B/£6. The massive MeyGen turbine project has been estimated so far to cost $1.56B/£1B. The $80m/£51 cost for Phase 1 of the project has already been raised.

Advocates of the tidal stream system suggest it can also be more environmentally compatible, since it does not act as an obstacle to wildlife. The Wash project, on the other hand, has come under fire because while proponents say that it will help reduce flooding in the area, critics say it can interfere with the migration of waterfowl. As many as 350,000 wading birds use the area each year.

Here in North America, tidal energy efforts have been met with mixed success. ORPC’s Cobscook, Maine pilot project was the first tidal energy array to successfully hook to the grid and is still under development. The company also operates a river-based system in Alaska that has been successful in generating electricity for remote “islanded” communities that are too far from main grids to obtain electricity. 

In the Bay of Fundy, Nova Scotia, Canada, effort is underway to establish a four-berth tidal energy facility that “can give Canadians the opportunity to acquire the know-how to deploy, service, and grid-integrate tidal turbines just as a world market opens up.” Canada supplies 59 percent of its energy from hydro sources, and has been exploring the prospect of developing a national east-west grid that would allow provinces to share such resources more evenly. At the present time, Canada’s electric is primarily north-south due to energy agreements with the U.S. Additional development of its tidal resources in places like Nova Scotia and Quebec on the east coast, and British Columbia on the west, would complement those efforts.

With projects like MeyGen, ORPC Ireland and numerous barrage projects underway, the U.K. is well positioned to become the world leader in tidal energy. Geography, climate and a lengthy investment in hydro electric development have made the British Isles uniquely suited for this type of energy production. It will be interesting to see how global investment and new advances in technology shape the future of this growing renewable energy industry.

Photo Credit: Atlantis Resources, LTD