HR: 10:20h
AN: A12C-01 [Abstracts]
TI: Evaluation of Global Wind Power and Interconnected Wind Farms
AU: * Archer, C L
EM: lozej@stanford.edu
AF: Stanford University, Stanford University, Stanford, CA 94305
AU: Jacobson, M Z
EM: jacobson@stanford.edu
AF: Stanford University, Stanford University, Stanford, CA 94305
AB:
The world wind power potential is evaluated in this study. Wind speeds are calculated at 80 m, the hub height of modern, 77-m
diameter, 1500 W turbines. Since relatively few observations are available at 80 m, the Least Square extrapolation technique
is utilized to obtain estimates of wind speeds at 80 m given observed wind speeds at 10 m (widely available) and a network
of sounding stations.
Globally, about 13% of all reporting stations experience annual mean wind speeds >= 6.9 m/s at 80 m (i.e., wind power
class 3 or greater) and can therefore be considered suitable for low-cost wind power generation. This estimate is believed to
be conservative. Of all continents, North America has the largest number of stations in class >= 3 (453). Areas with great
potential are found in Northern Europe along the North Sea, the southern tip of the South American continent, the island of
Tasmania in Australia, the Great Lakes region, and the northeastern and northwestern coasts of North America.
Assuming that statistics generated from all stations analyzed here are representative of the global distribution of winds,
global wind power generated at locations with mean annual wind speeds >= 6.9 m/s at 80 m is found to be approximately 72 TW
(54,000 Mtoe) for the year 2000. Even if only 20% of this power could be captured, it could satisfy 100% of the world's
energy demand for all purposes (6,995-10,177 Mtoe) and over seven times the world electricity needs (1.6-1.8 TW).
Several practical barriers need to be overcome to fully realize this potential. Wind intermittency could be perceived as one
of them. However, interconnecting wind farms through the transmission grid, also known as distributed wind power, is a simple
and effective way of reducing deliverable wind power swings caused by wind intermittency. As more farms are interconnected
in an array, wind speed correlation among sites decreases and so does the probability that all sites experience the same wind
regime at the same time. Consequently, the array behaves more and more similarly to a single farm with steady wind speed and
thus steady deliverable wind power.
Other benefits of interconnecting wind farms are: array-average wind speed and wind power standard deviations decreases as
the number of interconnected sites increases, decreasing intermittency and backup power requirements; reliability increases
to over 99% for a 7-site array; the frequency distribution of wind speeds changes from Rayleigh, when only one farm was
considered, to approximately Gaussian, when 19 farms are interconnected. Although these parameters improved less than
linearly as the number of interconnected sites increased, no saturation of the benefits was found. Thus, the benefits of
interconnection continue to increase with more and more interconnected sites.
DE: 0399 General or miscellaneous
DE: 3307 Boundary layer processes
DE: 3399 General or miscellaneous
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005