Re: [cdn-nucl-l] " Norway tries underwater 'windmills' "

[George Stanford <gstanford@aya.yale.edu>]

        The article mentions

"700,000
kilowatt hours of non-polluting 
energy a year, or enough to light and heat about 30
homes."

  If my
arithmetic is correct, that's an average output 80 kW, or 2.6 kW
per home.  Is that enough for a house in a Norwegian winter?.

        

"The plant in the Kvalsund channel, which had cost about 
$11 million by Saturday's launch . . . "

Again if my arithmetic is
correct, that's $137,000 per average installed kWe.  Compare
some $600 for a gas-fired plant, and maybe $1500 - $2500 for
a nuclear plant (or is my estimate for nuclear high?).

        George Stanford

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

At 04:35 PM 9/24/2003, Jaro Franta wrote:
Date: Wed, 24 Sep 2003 17:35:20 -0400

Something weird with the numbers in this article...  (installed capacity,
for one, seems very small, even assuming a low CF).

....but they sure don't mince words, when they state flatly that "Aboveground
windmills, by contrast, are useless in calm weather and have to be built to
withstand hurricane-force winds."

Wonder what the maintenance list includes... cleaning barnacles off the
blades ?

 Jaro
^^^^^^^^^^^^^^^^^^^^^

http://www.msnbc.com/news/969748.asp
Norway tries underwater 'windmills'
Tides turn blades, providing power to local homes    
 
OSLO, Sept. 22 -  Homes on the Arctic tip of Norway are getting power from
the moon via a unique underwater power station driven by the rise and fall
of the tide. Caused by the gravitational tug of the moon on the earth, a
tidal current near the town of Hammerfest is turning the 30-foot 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, told Reuters.
      
$11 MILLION PROJECT
       The plant in the Kvalsund channel, which had cost about $11 million
by Saturday's launch [ie. $15.71/kWh ??] is a tiny contributor to help cut
dependence on fossil fuels like oil and gas that many scientists blame
for global warming.
       The water flows at about 8 feet 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. Aboveground windmills, by contrast, are useless in calm weather
and have to be built to withstand hurricane-force winds.
       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.
      
INITIALLY MORE COSTLY
       Drawbacks are that costs are high. Hammerfest Stroem has estimated
that electricity will cost about three times that of typical hydro-generated
electricity in Norway.
And maintenance - with divers having to go down to the seabed - could be
tricky.
       Still, partners like Norwegian oil group Statoil are excited about
the prospects. "We want to get experience from this and see that we can also
be a producer of green electricity," said Hanne Lekva at Statoil.