Skip to main content
Part of complete coverage on

Tide turns towards undersea energy

By Eoghan Macguire, for CNN
updated 10:39 AM EDT, Fri June 1, 2012
Scottish Power has been testing the HS1000 sub-sea turbine in the fast flowing coastal waters of the Orkney Islands in Northern Scotland. Scottish Power has been testing the HS1000 sub-sea turbine in the fast flowing coastal waters of the Orkney Islands in Northern Scotland.
HIDE CAPTION
Capturing the power of the ocean
Underwater and out of sight
Power to the people
To the power of ten
World first
High costs of renwable energy
<<
<
1
2
3
4
5
6
>
>>
STORY HIGHLIGHTS
  • Scottish Power Renewables has successfully tested a new type of underwater tidal turbine
  • The device can produce 1 megawatt of electricity, enough to power 500 homes and businesses
  • A fleet of ten underwater turbines could be installed off the West coast of Scotland
  • This would be the first sub sea turbine farm anywhere in the world

(CNN) -- A 30-meter- turbine anchored to the seafloor off the Scottish coast is proving that tidal farms are a turn closer to being a viable renewable energy source.

Scottish Power completed preliminary trials of the giant undersea turbine in the fast-flowing coastal waters off the Orkney Islands. It found that the turbine produced one megawatt of electricity, enough to power 500 homes and businesses.

"We're very pleased with the initial results and we've operated at full power already," says Alan Mortimer, head of innovation at Scottish Power Renewables.

If the next stage of testing goes according to plan, Mortimer says that work will soon begin on a fleet of the turbines -- manufactured by Andritz Hydro Hammerfest -- and will be installed at another site in the Sound of Islay off the west coast of Scotland.

Although there are examples of similar stand-alone operations in Norway and the UK, the Sound of Islay turbines would be the first large group of its kind anywhere in the world. When fully operational it is estimated to produce electricity for 5,000 homes.

Other countries with strong tidal resources and potential sites for tidal power farms include Argentina, Chile, the U.S. and Canada.

Compared to offshore wind farms, tidal energy devices like the turbine trialed in Scotland are completely hidden from view.

They are criticized for being potentially harmful to marine life, but Mortimer contends that because the turbine's propellers move relatively slowly, the impact on fish and other forms of sea life is minimal.

See also: World's oceans are 'plasticized'

Scottish Power says that it already has planning consent and a lease for the seabed where the tidal farm will be built. However the main obstacle to the implementation of more tidal farms remains the cost.

"We have publicly stated that we expect the capital costs of the Islay project to be around £70 million ($110 million)," says Mortimer, which equates to roughly $11 million per turbine.

The 10 megawatts of power that will be generated by the Sound of Islay turbine farm pales into insignificance when compared to the output of a large nuclear or coal power station, which according to American hydro energy non-profit the Ocean Energy Council, can produce up to 100 times as much electricity.

Mortimer is quick to point out that he believes such challenges are inevitable in developing new technologies and that costs would fall and efficiencies improve as the fledgling industry develops.

"The estimate for the UK in terms of wave and tidal is that it could eventually produce in excess of 10% of the country's electricity requirements," says Mortimer. "That's definitely big enough to make it of interest for us to pursue it."

ADVERTISEMENT
Part of complete coverage on
updated 9:30 PM EST, Sun January 20, 2013
Patricia Wu looks at efforts to combat food waste in Hong Kong.
updated 9:33 PM EST, Sun January 13, 2013
CNN's Pauline Chiou goes to Hong Kong's annual toy fair to find out about the growing market for eco-friendly toys.
updated 11:15 PM EST, Sun December 30, 2012
CNN's Liz Neisloss reports on a roof that is only a sample of the greening of Singapore's skyline.
updated 9:16 PM EST, Tue December 18, 2012
A dam project in Cambodia could destroy livelihoods and ecosystems, says Conservation International
updated 10:22 PM EST, Mon December 17, 2012
Shipping lines, port authorities and technology companies are taking the initiative to go green and reduce costs.
updated 9:06 PM EST, Sun December 9, 2012
Less than 20 miles from Singapore's skyscrapers is a completely different set of high-rise towers.
updated 6:04 AM EST, Thu December 6, 2012
The Pitcairn Islands might only have 55 human inhabitants, but the waters surrounding them are teeming with marine life.
updated 10:22 PM EST, Sun December 2, 2012
Biofuel made from sugar cane waste in Brazil could revolutionize the global energy industry.
updated 9:58 PM EST, Sun November 25, 2012
Many believe that fuel-cell cars will overtake electric vehicles in the near future.
updated 3:20 AM EST, Mon November 19, 2012
Modern and sustainable buildings in the UAE are taking cues from an ancient Arabic design tradition.
updated 11:09 PM EST, Sun November 11, 2012
One man's artistic vision is distracting divers from Cancun's threatened underwater ecosystem.
updated 12:46 PM EST, Mon November 12, 2012
Lake Victoria, Africa's largest lake, has been plagued by water hyacinth plants for over two decades.
A turtle on Australia's Great Barrier Reef
Just how much are natural wonders like the Great Barrier Reef worth in monetary terms?
ADVERTISEMENT