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Great Lakes
Article:
Global Wind Map May Provide Better
Locations For Wind Farms
American Geophysical Union
Posted on Science Daily May 16, 2005
WASHINGTON - A new global wind power map has quantified
global wind power and may help planners place turbines
in locations that can maximize power from the winds and
provide widely available low-cost energy. After analyzing
more than 8,000 wind speed measurements in an effort to
identify the world's wind power potential for the first
time, Cristina Archer and Mark Jacobson of Stanford University
suggest that wind captured at specific locations, if even
partially harnessed, can generate more than enough power
to satisfy the world's energy demands. Their report will
be published in May in the Journal of Geophysical Research-Atmospheres,
a publication of the American Geophysical Union.
The researchers collected wind speed measurements from
approximately 7,500 surface stations and another 500 balloon-launch
stations to determine global wind speeds at 80 meters
[300 feet] above the ground surface, which is the hub
height of modern wind turbines. Using a new interpolation
technique to estimate the wind speed at that elevation,
the authors report that nearly 13 percent of the stations
they reviewed experience winds with an average annual
speed strong enough for power generation. They note that,
based on their expectations of other global areas, an
even greater percentage of locations would likely reach
the 6.9 meters per second [15 miles per hour] wind speed
considered strong enough to be economically feasible.
Such wind speeds at 80 meters, referred to as wind power
Class 3, were found in every region of the world, although
North America was found to have the greatest wind power
potential. The researchers also found that some of the
strongest winds were observed in Northern Europe, along
the North Sea, while the southern tip of South America
and the Australian island of Tasmania also recorded significant
and sustained strong winds at the turbine blade height.
In North America, the most consistent winds were found
in the Great Lakes region and from ocean breezes along
the eastern, western and southern coasts. Overall, the
researchers calculated winds at 80 meters [300 feet] traveled
over the ocean at approximately 8.6 meters per second
and at nearly 4.5 meters per second over land [20 and
10 miles per hour, respectively].
"The main implication of this study is that wind,
for low-cost wind energy, is more widely available than
was previously recognized," Archer said. "The
methodology in the paper can be utilized for several applications,
such as determining elevated wind speeds in remote areas
or to evaluate the benefits of distributed wind power."
The study also estimated the amount of global wind power
that could be harvested at locations with suitably strong
winds. The authors found that the locations with sustainable
Class 3 winds could produce approximately 72 terawatts
and that capturing even a fraction of that energy could
provide the 1.6-1.8 terawatts that made up the world's
electricity usage in the year 2000. A terawatt is 1 billion
watts, a quantity of energy that would otherwise require
more than 500 nuclear reactors or thousands of coal-burning
plants. Converting as little as 20 percent of potential
wind energy to electricity could satisfy the entirety
of the world's energy demands, but the researchers caution
that there are considerable practical barriers to reaping
the wind's potential energy.
Chief among those barriers is creating and maintaining
a dense array of modern turbines that would be needed
to harness the wind power. Some sources have suggested
that millions of turbines would be needed to produce an
acceptable level of energy and that alternative energy
sources would still be necessary to produce power when
the wind speeds fall below a certain threshold. Creating
a large field of turbines could also be hazardous to birds
and may produce unacceptable noise levels.
The current research, however, indicates that several
of those limitations can be overcome with better placement
of wind turbines. The researchers report that their study
can assist in locating wind farms in regions known for
strong and consistent winds, which may help avoid some
of the problems with intermittent winds. In addition,
they suggest that the inland locations of many existing
wind farms may explain their inefficiency.
"It is our hope that this study will foster more
research in areas that were not covered by our data, or
economic analyses of the barriers to the implementation
of a wind-based global energy scenario," Archer concluded.
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The research was supported by NASA and by Stanford University's
Global Climate and Energy Project (GCEP).
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