Monday, February 10, 2014

THE LATEST SCOOP ON WIND ENERGY

The Sochi 2014 Winter Olympics
Medal standings
COUNTRY                  GOLD              SILVER            BRONZE
 1 Canada 3 3 1 7 2 Netherlands 3 2 2 7 3 Norway 2 1 4 7 4 United States 2 0 3 5 5 Germany 2 0 0 2 6 Russia 1 2 3 6 7 Austria 1 2 0 3

A quick course in wind energy.  The equation to remember is that the power produced is the cube of wind velocity.  Thus, a 20 miles/hour wind site produces 20/10 x 20/10 x 20/10 = 2x2x2 = 8 times the power of a 10 MPH location.  While it should make some common sense that there are only two types of wind energy conversion devices (WECS, horizontal and vertical axes), this diagram shows three, two vertical:

The optimal propeller-type WECS has only ONE blade, with a counterweight.  I think that's Paul Gipe to the left (forty years ago I chaired the Wind Power Division of the American Solar Energy Society, and he looked a lot younger then).  This maximizes the conversion efficiency.  However, no one builds this variation because it is metastable.  Two blades are thus the most efficient sold, and three or more can be used for specific applications.

Here is a presentation that argues for the latter.  Likewise, here is a high school guide that says that a three bladder is 5%  more efficient than a two blade system, which is 10% more efficient than a single blade system because it does not have to rotate so fast.   Likewise, Wikipedia says that an infinite number of blades of zero width is the most efficient, something that is impossible.  If this has confused you, such is the nature of wind power, which at one time was an ideal form of renewable energy, but now seems to have incurred some backlash because of noise, aesthetics and size.

1.  Vestas V164 8MW:  came online only last month at the Danish national wind test center in Osterild.  This machine will be able to supply electricity for 7,500 European households.  The V164 reaches up 722 feet, two feet longer than the length of two football fields.

2.  Enercon E126 7.6MW:  146 German E-126 wind turbines are now operating, in construction or nearing final approval.  Each costs \$14 million and reaches up 650 feet tall.

3.  Samsung S7.0 171 7MW:  this very first of Samsung's WECS is ready for  testing 20 meters offshore in Fife, Scotland.  It is 643 feet tall.  Samsung has reportedly invested around \$100 million over the past five years.

Who leads the world in wind energy production?
Top 10 countries
by windpower electricity production
(2011 totals)[59]
CountryWindpower production
(TWh)
% world total
United States120.526.2
China88.619.3
Germany48.910.6
Spain42.49.2
India24.95.4
UK15.53.4
France12.22.7
Italy9.92.1
Denmark9.82.1
(rest of world)67.714.7
World total459.9 TWh100%
However, the leadership changes for nameplate capacity:
Top 10 countries
by nameplate windpower capacity
(2012 year-end)[45]
CountryNew 2012
capacity (MW)
Windpower total capacity
(MW)
% world total
China12,96075,32426.7
United States13,12460,00721.2
Germany2,14531,30811.1
Spain1,12222,7968.1
India2,33618,4216.5
UK1,8978,8453.0
Italy1,2738,1442.9
France7577,5642.7
Portugal1454,5251.6
(rest of world)6,73739,85314.1
World total44,799 MW282,587 MW100%
Note that a typical nuclear power plant is around 1000 MW, so the world total wind energy capacity now is equivalent to nearly 300 nuclear facilities.  Well, not quite, as nuclear generation has a power capacity of 90%, while that of WECS is 25%.  Thus, doing the math, those WECSs above would be the equivalent of 79 nuclear power plants.  Clearly, this is produced by the nuclear industry, but here they compare land use of the two options:

Click on the above to read the fine print, but it says:

• there are 2077 2MW wind generators,
• and one 1154MW nuclear power plant produces the same amount of electricity annually,
• yet, if you read the article, the nuke site, including buffer space, would occupy one square mile, while those 2077 WECS would need 318 square miles.
However, it can be argued that wind farms, while producing electricity, can still be used for agricultural and other applications, while, as has happened too often, a Chernobyl or Fukushima cataclysm wipes out a large swatch of land for hundreds of years.  How large?  Well, there is increased radioactivity over 11,580 square miles around Fukushima, with 4500 square miles (about the size of Connecticut) having radiation levels that exceed allowable limits.

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