Sustainable Energy

Tapping the Tides

First “underwater windmill” hitting the grid.

A handful of tidal-power plants dot the world, and most of them are sprawling facilities that impound incoming water in estuaries, block shipping, and disrupt marine life. But 50 meters under the sea, at the bottom of a remote Norwegian strait, the world’s first unobtrusive, grid-connected “watermill” will soon produce power for the world’s northernmost town.

It looks like a wind turbine, except it’s anchored to the seabed. Tidal currents moving at 2.5 meters per second spin three 10-meter fiberglass blades, generating power that is sent to the grid via a cable. When the tide turns, the blades twist 180 degrees, reversing the direction of the watermill’s rotation. Electricity from the 200-ton apparatus is expected to hit the grid this spring, providing enough power for between 40 and 50 houses. “This is the first mill-type system hooked up to the grid,” says Anthony Jones, a San Francisco-based ocean-energy consultant. “I’m betting that they’ll be quite successful.”

That’s partly because Hammerfest Strom, the company behind the project, tapped ocean-engineering expertise from partners that include Zurich, Switzerland-based ABB and Statoil in Stavanger, Norway. Project leader Bjorn Bekken says a modular design allows replacement of broken parts, while redundant hydraulics and control systems should minimize service calls. Eventually, repairs will be performed by remotely operated vehicles similar to those used on offshore oil platforms.

This story is part of our May 2003 Issue
See the rest of the issue
Subscribe

The prototype is the first and smallest of 20 mills slated for the Kvalsund Strait-near the town of Hammerfest, 1,360 kilometers north of Oslo. They will supply enough power for 800 to 1,000 houses within a few years. Although it is twice as costly as wind power right now, “the watermill has just started its development, and I think it will be competitive with the windmill within 10 years,” says Ole G. Dahlhaug, an engineer at the Norwegian University of Science and Technology in Trondheim, Norway.

Hammerfest Strom isn’t the only company aiming to build watermills. Hampshire, England-based Marine Current Turbine plans to install a prototype watermill just beneath the waves off the coast of Lynmouth, England, by early summer. Together, these efforts could turn the tide for this renewable power source.

Become an MIT Technology Review Insider for in-depth analysis and unparalleled perspective.

Subscribe today

Uh oh–you've read all of your free articles for this month.

Insider Premium
$179.95/yr US PRICE

More from Sustainable Energy

Can we sustainably provide food, water, and energy to a growing population during a climate crisis?

Want more award-winning journalism? Subscribe to Insider Plus.
  • Insider Plus {! insider.prices.plus !}*

    {! insider.display.menuOptionsLabel !}

    Everything included in Insider Basic, plus ad-free web experience, select discounts to partner offerings and MIT Technology Review events

    See details+

    What's Included

    Bimonthly home delivery and unlimited 24/7 access to MIT Technology Review’s website.

    The Download. Our daily newsletter of what's important in technology and innovation.

    Access to the Magazine archive. Over 24,000 articles going back to 1899 at your fingertips.

    Special Discounts to select partner offerings

    Discount to MIT Technology Review events

    Ad-free web experience

/
You've read all of your free articles this month. This is your last free article this month. You've read of free articles this month. or  for unlimited online access.