| Moon
Brings Green Power
to Arctic Homes
Reuters International
Posted October 3, 2003
OSLO: Homes on the Arctic tip of Norway started getting
power from the moon on Saturday via a unique subsea power
station driven by the rise and fall of the tide. A tidal
current in a sea channel near the town of Hammerfest, caused
by the gravitational tug of the moon on the earth, started
turning the 10-metre (33 ft) blades of a turbine bolted
to the seabed to generate electricity for the local grid.
The prototype looks like an underwater windmill
and is expected to generate about 700,000 kilowatt hours
of non-polluting energy a year, or enough to light and heat
about 30 homes. “This is the first time in the world
that electricity from a tidal current has been fed into
a power grid,” Harald Johansen, managing director
of Hammerfest Stroem which has led the project, told Reuters.
The plant in the Kvalsund channel, which had cost about
80 million crowns ($11 million) by Saturday’s launch,
is a tiny contributor to help cut dependence on fossil fuels
like oil and gas blamed for global warming. The water flows
at about 2.5 metres (8 ft) per second for about 12 hours
when the tide is rising through the Kvalsund channel, pauses
at high tide and then reverses direction. The blades on
the turbine automatically turn to face the current.
If successful, the project could herald far
wider use of predictable tides in green energy and generate
millions of dollars in orders. Windmills, by contrast, are
useless in calm weather and have to be built to withstand
hurricane-force winds.
Artificial lagoons: Tides have previously been tapped for
power plants in France, Canada and Russia in barrages that
trap water in artificial lagoons at high tide. When the
tide goes out, gravity sucks the water through turbines
to generate electricity. But such barrages can disrupt the
habitats of animals and plants in river estuaries and along
the coasts.
Proponents of turbines turned by tidal currents say that
they cause less impact — they are silent and invisible
from the surface and fish, whales and seals can probably
swim round them without the risk of being sliced up. Drawbacks
are that costs are high. Hammerfest Stroem has estimated
that electricity will cost about 0.30-0.35 crowns a Kilowatt
hour to generate, three times that of typical hydro-generated
electricity in Norway. And maintenance — with divers
having to go down to the seabed — could be tricky.
Other subsea experiments to generate power from tidal currents
from Australia to Britain have not got to the stage of feeding
power into the grid.
Reuters International
- Back
to News Home -
|