Artwork illustrating four rotor TidalStream SST tidal turbine units in a typical application (Image source: wikimedia commons)

Artwork illustrating four rotor TidalStream SST tidal turbine units in a typical application (Image source: wikimedia commons)

No, it’s not an article about 80s music, but rather a glimpse into a promising source of renewable energy: the deep blue sea. Hydroelectric power is nothing new, but it has traditionally been generated through the use of river dams, which can have some negative effects on the environment. Two experimental categories of ocean-based electricity generation are currently being tried out in several locations around the world: tidal power (or tidal energy) and wave power.

 

Anyone who has stood on a beach, watching and listening to the awesome roar of the waves as they crash onto the shore, or experienced the massive pull of ocean tides, has surely been impressed by their staggering force. Mankind has been utilizing the power of the tides since perhaps as far back as Roman times, mostly as mills. Now in an age when finding alternative, sustainable energy sources is becoming more and more crucial, tidal and wave power may offer great options for electricity needs in coastal locations. One advantage of tides and waves is that they are consistent compared to the unpredictable nature of sunshine and wind.

Tidal Power

There are three main varieties of tidal power generators:

  1. Barrages operate similarly to dams and pose some of the same environmental concerns.
  2. Tidal stream systems use basically the same principle as wind turbines, yet are located underwater.
  3. Tidal lagoons are like self-contained barrages, yet do not fully span estuaries or have the same environmental risks or costs.

Below is a report by The Nation (CBC Canada) on tidal energy in the Bay of Fundy, Nova Scotia. It is hoped that one seventh of Nova Scotia’s energy needs could be provided for by tidal power generators. The government of the Canadian province hopes to use its tidal stream system to power close to 100,000 homes.

The “giant sea snake” method

New Zealand also plans a tidal generator near its capital Wellington. Within 10-15 years New Zealand’s Neptune Power would like to have a team of 30 underwater turbines providing more power than the entire current grid. However, tidal turbines are still considered to be in the experimental stage and their possible impact on wild life such as dolphins is as of yet unknown.

Wave Power

The Pelamis Wave Energy Converter, Aguçadoura wave farm, northern Portugal (Image source: wikimedia commons)

The Pelamis Wave Energy Converter, Aguçadoura wave farm, northern Portugal (Image source: wikimedia commons)

The world’s first wave power energy farm is the Aguçadoura Wave Park near the city of Porto in northern Portugal. The Wave Energy Converters that make up the farm are made by a Scottish company called Pelamis Wave Power. Pelamis is an Ancient Greek term for sea snake, which the serpentine metal behemoths resemble. Looking nothing like any other power source, the snake-like generators float atop the ocean and ride the swell, their four sections twisting and turning in the push and pull of the waves. The sections are connected to one another by power modules, which in turn generate electricity from this movement and send it to land via cable.

Future sights for similar wave energy farms include Orcadian Wave Farm and EMEC north berth, both off the northwest coast of Scotland, according to a BBC story from last year. Additional Pelamis projects are also planned for Norway, Spain, France, South Africa and North America.

What wave power and tidal power projects demonstrate, like wind and solar energy ventures, are clever and enterprising endeavors to use what nature provides, yet – most importantly – in sustainable ways. Though these technologies are still in their experimental stages, they look very promising and are – in theory – more dependable than wind and solar energy.

Additional resources:
Portugal opens the world’s first wave power farm news report from France 24
Wave Energy To Be Harnessed Off Maui KITV News (ABC) report
Grist.org article about tidal energy in the Puget Sound

About The Author: Graham Land

Greenfudge editor and London-based writer Graham Land grew up in the suburbs of Washington, DC, where he was part of the local hardcore punk scene, playing in several bands. Through this musical movement he became involved in grass roots interests such as anti-racist activism, animal rights and Ecology. In 2000 he relocated to Europe, eventually earning an MA from Malmö University in Sweden. He has also lived in Japan, Ireland, Portugal and Greece.



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