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Wind Farming Earth
A Global Impact
By Nathan Randol
8/1/2012
Weather shapes the landforms of the world. Now humans are
reshaping the landforms. What becomes of weather?
Wind Farming Theory
Wind energy has been around since the beginning of time. It is only recently,
through farming, that humans began pursuing wind energy as a means for electrical
energy and to offset the amount of carbon emissions produced by other forms of energy
production. Wind farming is seen as a green, renewable, free energy source. This idea of
endless green energy at no cost is an illusion. The truth is that all energy comes and goes
at some cost. Whether something is killed for food or mined to be burned for heat, all
forms of energy come at some cost. The question for wind farming is: What costs are we
paying to obtain this energy for our personal use? This paper looks into how weather is
created, wind farms and what effects it has on the Earth.
Weather Creation
“The Sun’s heat (solar energy) is the origin of all our weather. It causes air
masses to form and circulate in our atmosphere. This movement creates differences in air
pressure which, in turn, create winds [1-pg 26]”. “Numerous factors affect the amount of
solar energy reaching the earth, including cloud cover, reradiation of heat from the land
and the sea, and winds [1-pg 27]”. These factors combined with solar energy make up the
inner workings of the atmosphere. Diagram 1, Earth’s Energy Budget, shows a rational
make up of this system [2, 3].
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Earth’s Energy Budget [2]
Diagram 1
In the book A Guide to Weather, “The atmosphere constantly works toward
equilibrium, attempting to “smooth out” the world’s irregular temperatures by carrying
warm air from the equator toward the poles and draws cold air from the poles toward the
equator. However, as this happens, the air is redirected by the Earth’s rotation, slowed
down by friction with the land and sea, and held within the confines of the atmosphere by
gravity. Together, these cycles and forces create complex, ever-changing patterns that
make up our weather [1-pg 16]”.
Wind farms
A wind farm creates electrical energy by the use of wind turbines. According to
the U.S. Department of Energy, “a wind turbine works the opposite of a fan. Instead of
using electricity to make wind, like a fan, wind turbines use wind to make electricity.
The wind turns the blades, which spin a shaft, which connects to a generator and makes
electricity [4]”. Today an industrial turbine for wind farms can range in height of 197 –
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344 feet (excluding the blade height) [5]. Blade diameters vary in size of 204 – 368 feet
[5].
The electrical capacity that can be farmed per unit is anywhere from 1 Megawatt
(MW) to 6 MW [5]. In the U.S. the most common turbines used in farming are 1.5 MW
and 3 MW [5].
A general view of a wind farm layout can best be described by the model
constructed in a study by Somnath Baidya Roy and Justin J. Traiter, 2010 [6]. The model
had “turbines 100m (300ft) tall with (an extra) 50m (150ft) (for the) rotor blades (100m
(300ft) rotor diameter), spaced 10 rotor diameters, i.e. 1km (3,000ft) apart [6].” Farms are
built in strategic locations where wind movement is constant and strong, as on top of
mountain ranges, narrow valleys, ocean or lake shores, and the flat lands at the base of
mountain ranges. Almost every U.S. state has a wind farm. In 2010, the top five largest
wind farm areas in the U.S. were Texas (10,223 MW), Iowa (3,708 MW), California
(3,599 MW), Minnesota (2,681 MW), and Illinois (2,438 MW) [7].
The first large industrial wind farm was built in the mountain passes of San
Gorgonio, California in the 1980s. It consists of 17,000 wind turbines, ranging between
20 to 350 kilowatts (KW) [8]. Then, in the 1990s, public concern about environmental
issues such as air pollution and climate change became center stage [8]. Government
leaders around the world took greater interest in using renewable energy to address these
issues [8]. By means of regulations and subsidies, wind farms began to grow in the U.S.,
Europe, Canada, and India [8]. In 2001, China became involved as well [8]. The growth of
installed wind energy capacity of the world since 1996 is shown in Diagram 2.
Global Cumulative Installed Wind Capacity 1996-2010
250,000
197,039
200,000
158,908
MW 150,000
120,291
93,820
100,000
50,000
6,100
7,600
1996
1997
17,400 23,900
10,200 13,600
31,100 39,431
47,620
59,091
74,052
0
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
World’s Installed Wind Capacity [9-pg. 14]
Diagram 2
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This growth over a 14 year span has been a steady yearly average rate of 28%. The
Global Wind Energy Council (GWEC) predicts the world’s installed wind energy
capacity will grow to around one Terawatt (TW) by 2020 [9].
Wind Farming and Earth’s Energy Budget
Looking at the Earth’s Energy Budget (Diagram 1) as a balanced equation is a
straight forward approach to evaluating the effects of wind farming. The current equation
has the variables of solar energy to Earth’s surface “In” and wind, clouds, and radiation
of Earth’s surface “Out”, see Equation 1.
Solar Energy to
Earth's Surface
51%
=
Wind by
Conduction &
Rising Air 7%
+
Clouds
23%
+
Radiation of
Earth's Surface
21%
Equation 1
If the equation becomes unbalanced, such as an increase in clouds, then solar
energy would be deflected out of the Earth due to more clouds, radiation of Earth’s
surface would drop, and winds would shift bringing the equation back towards balance.
If, instead, clouds decreased, then more solar energy would be allowed in, radiation of
Earth’s surface would increase, and more wind would be created. The same changes
occur when any of the variables shift. In our ever changing world these variables
fluctuate constantly as a cycle of weather, all in an effort to balance this equation.
Now add wind farms into the equation. The Earth’s wind energy drops due to the
harvesting by wind farms. The new variable to Equation 1 is shown in Equation 2.
Solar Energy to
Earth's Surface
51%
=
Wind by
Conduction &
Rising Air 7%
-
Wind
Farmed
Energy
+
Clouds
23%
+
Radiation of
Earth's Surface
21%
Equation 2
To balance Equation 2 the solar energy reaching Earth’s surface needs to increase. The
only way to do that is to allow more solar energy in without being reflected out (see
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Earth’s Energy Budget for reflection factors, Diagram 1). The extra solar energy needed
to offset the loss in wind would also impact the other variables. This new effect of wind
farming, on a large scale, would cause winds to move less fluidly or slower from equator
to poles and vice versa. This would change the current weather cycle. The new cycle
would start with an increase in radiation (surface temperature), higher humidity (drying
of the land of water to make clouds), and delayed winds. This would lead to greater high
and low pressure systems. As the systems build and are delayed from mixing, the
chances for unstable weather conditions grow. If wind movement is delayed too long,
then these unstable pressure systems can not only build in strength but drift farther out of
their average area towards the poles or equator before mixing to dissipate their condition.
This could lead to stronger storms and in areas where they are not common.
A cooling phase would then follow to bring down the spike in temperatures from
the previous warming phase. The clouds created during the warming phase start the
cooling phase by reflecting out more of the solar energy in. This would cause the planet
to cool down. Since the equation was high in the warming phase, it must swing into the
cooling phase to compensate. This cycle repeats with the purpose of “smoothing out” the
irregularities of the equation. So this cycle, as a whole, would have the Earth’s weather
fluctuating greater from low and high temperatures, clouds, winds, humidity, and storm
strengths.
Some supporting examples of fluctuations in the Earth’s Energy Budget can be
found throughout Earth’s past and present. Some are small and some large. No matter
the size, they do affect the area around them where ever they occur. A small example is
the hedge or trees that are put up around a person’s back yard. It blocks the wind,
changing the surrounding area to be more pleasurable for social gatherings and
preventing wind damage [1]. A similar situation is the installation of man made snow
fences along the highways of Wyoming [10]. They are designed to block the snow drifts
and high winds of winter that cause dangerous driving conditions for trucks and cars [10].
These structures also make the area behind them warmer, which is why wild antelope
take shelter behind them.
Larger examples are the tall structures that make up a big city. These structures
reduce and divert wind, making it flow less fluidly through a city to cool it and flush out
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smog [1]. This reduction of wind combined with few solar absorbing plants in a city
causes an increase in surface radiation energy making the city hotter then the surrounding
areas. This is known as urban weather [1].
An example bigger yet is the U.S. “Dust Bowl” of the 1930s. At that time, the
Midwest was being over farmed and the land poorly managed [11]. Those actions caused
the loss of plant life that would absorb solar energy [11]. Instead, that energy went to
surface radiation and wind energy which greatly dried the land, and caused more loss of
plant life [11]. This lead to massive droughts, very hot days and strong dust storms that
turned day to night where ever they went, even as far as Washington D.C. [11]. This
disaster severely impacted 27 states and affected more then 75 percent of the country
making life in that decade almost impossible [11].
Government and private sectors also have examples of tampering with the Earth’s
Energy Budget by means of cloud seeding (cloud reduction). “Cloud seeding is the
attempt to change the amount or type of precipitation that falls from clouds, by dispersing
substances into the air that serve as cloud condensation or ice nuclei [12].” Seeding
operations started in 1947 by the U.S. followed by commercial use in the 1950s and is
still used today around the world [1, 13]. The largest use of cloud seeding occurred
between 1950s – 1980s [1]. The purpose for cloud seeding ranged from needed rainfall in
times of drought, increasing snow pack for snow resorts, cleansing air pollution, military
tactics, and attempting to weaken hurricane systems [1, 12, 13]. Few operations succeeded
but overall there has been no conclusive evidence that cloud seeding has increased
precipitation in seeded areas [1, 12, 13]. Instead, these areas experienced cases of deadly
flash floods, severe droughts down stream of seeded areas, and hurricanes altering course
that impacted people [1, 13].
Much larger examples that altered the Earth’s Energy Budget to a point that
affected much of the world are massive volcanic eruptions. One such eruption was Mt.
Tambora, Indonesia in 1815. The eruption put so much volcanic ash into the atmosphere
(cloud creation) that it created global climate anomalies that affected North American and
European weather the following year [14]. “1816 came to be known as the "Year Without
a Summer"[14-pg 1].” It caused agricultural crops to fail and reduced livestock in much of
the Northern Hemisphere, resulting in the worst famine of the 19th century [14].
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The largest reported example of Earth’s Energy Budget fluctuation is the meteor
impact that killed the dinosaurs [15]. So much dust, ash, water, and other Earth matter was
forced into the atmosphere by the meteor impact that the Earth was completely blanketed
by clouds [15]. This caused solar energy to be completely reflected out of Earth [15]. The
absence of solar energy caused a large planet cooling that lead to the extinction of many
species, including the Dinosaurs [15].
So how much extra solar energy is needed to balance the equation due to wind
farming? In 2010 the global wind farming installed energy capacity was 196,630 MW
(World Wind Energy Report 2010) [16]. The amount of solar energy needed to offset the
drain by wind farming can be determined by working the Earth’s Energy Budget
backwards as in Equation 3.
E
x Wind by Conduction
& Rising Air 7%
=
Wind Farmed Energy
Wind Farmed Energy
E
=
E
=
196,630 MW
7%
E
=
2.809 TW
Wind by Conduction &
Rising Air 7%
Equation 3*
The solar energy needed (E) reflects the amount of solar energy in from the sun
(refer to Earth’s Energy Budget, Diagram 1). Wind is only created when solar energy
reaches the Earth’s surface. That amount is 51% of E (refer Diagram 1). Therefore 51%
of E is 1.433 TW. That is the amount of solar energy needed to reach the Earth’s surface
to balance the offset that wind farming consumes. Since the solar energy from the sun
can not be increased, the only way to balance the equation is to change the reflection
variables percentages to allow more solar energy to reach the Earth’s surface. This
would result in warmer surface temperatures that lead to the creation of more wind.
*
To convert equation from power (watts) to energy use (watts/hour) divide by time.
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The other side effect of wind farming the Earth’s Energy Budget is that the extra
solar energy needed to feed wind farms also dumps energy into the cloud and surface
radiation variables. Those amounts are 23% clouds and 21% surface radiation of E,
shown in Equation 4.
Clouds
Clouds
=
=
=
23% x E
Surface Radiation
23% x 2.809 TW
646.07 GW
Surface Radiation
=
=
=
21% x E
21% x 2.809 TW
589.89 GW
Equation 4
In summery, wind farming the Earth’s Energy Budget requires an additional
1.433 TW of solar energy reaching the Earth’s surface to balance the equation. Of that
amount, 646.07 Gigawatts (GW) goes to forming additional clouds, 589.89 GW of
additional radiation to the Earth’s surface, and 196,630 MW goes to wind farms.†
Other side effects of wind farms are that, at approximately 450ft tall (including
blade height), they pose an obstacle for the fluid movement of wind. The strategic
locations of these structures make the path of least resistance for wind no longer the
easiest path. As an example, instead of going over the mountain ranges of the U.S. to the
Midwest, wind may find it easier to flow south through New Mexico or north to Canada,
taking with it any moisture and air temperature that would normally flow over the
Midwest. Another problem with the placement of these structures is on top of mountains.
These tall structures artificially raise the height of the mountain. The extra height
increases the rain shadow effect (this is when mountains force weather fronts to
condensate and make rainfall as they attempt to go over them) [1]. This would alter the
annual rainfall accumulation and temperatures on both sides of the mountain [1].
†
Keep in mind this is the wind energy that is reported as farmed and does not include the wind resistance
of the turbine leg, wind energy to electrical energy conversion loss, or the wind resistance of the wind
farms that are shutdown purposely during high winds to prevent motor damage (they still stand and block
wind when they are not spinning). These factors drain additional energy from the Earth’s Energy Budget
that is not reported.
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Conclusion
Wind farming and other means of green energy do not come free. Wind farming
comes at the cost of the Earth’s ability to moderate planet temperatures through weather.
The relatively little amount of wind energy farmed around the world in 2010 has the
atmospheric system adjusting to allow 1.433 TW of additional solar energy to the Earth’s
surface to balance this drain. That additional energy fuels the entire weather system. Of
that amount, approximately 86% goes to creating additional clouds and altering surface
temperatures while the rest supplies the wind farms. This variation in energy and the
reshaping of Earth’s landforms changes the cycle and strength of the current weather.
The weather that dictates the sort of life we lead for happiness, food, shelter,
transportation, communication, economy, etc. Just because humans have been able to
find new ways to satisfy their needs does not always mean that it should be implemented,
especially when it involves weather. If it is implemented, it should be in moderation and
well thought out. If not, then expect the unexpected and the hardships that are sure to
come.
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Reference:
1.
William J. Burroughs, Bob Crowder, Ted Robertson, et al. A Guide to Weather. San Francisco,
CA; Fog City Press; 2002.
2.
NASA. Earth’s Energy Budget. Web site. http//asd-www.larc.nasa.gov/erbe/components2.gif.
Accessed April 29, 2012.
3.
Jack Williams. The AMS Weather Book: The Ultimate Guide to America’s Weather. Chicago, IL;
University of Chicago Press; 2009.
4.
U.S. Department of Energy. (2010). How Wind Turbines Work. Web site
http://www1.eere.energy.gov/wind/wind_how.html. Accessed March 14, 2012.
5.
American Wind Energy Opposition. Size Specifications of Common Industrial Turbines. Web site.
www.aweo.org/windmodels.html. Accessed March 14, 2012.
6.
Somnath Baidya Roy and Justin J. Traiteur. Impacts of wind farms on surface air temperatures.
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7.
U.S. Department of Energy. Wind Powering America. Web site
http://www.windpoweringamerica.gov/wind_installed_capacity.asp. Accessed March 14, 2012.
8.
Centre for Energy. Wind Energy Timeline. Web site
http://www.centreforenergy.com/AboutEnergy/History.asp?print=1. Accessed December 5, 2011.
9.
Global Wind Energy Council. Global Wind Report, Annual Market Update 2010; GWEC – Global
Wind 2010 Report.
10. Tabler, R. D. 2003. Controlling Blowing and Drifting Snow with Snow Fences and Road Design.
NCHRP Project 20-7(147). Transportation Research Board of the National Academies,
Washington, D.C.
11. United States History. The Dust Bowl. Web site http://www.u-s-history.com/pages/h1583.html.
Accessed April 24, 2012.
12. New World Encyclopedia. Cloud seeding. Web site
http://www.newworldencyclopedia.org/entry/Cloud_seeding. Accessed April 29, 2012.
13. Ronald B. Standler (2002). History and Problems in Weather Modification. Web site
http://www.rbs2.com/w2.htm. Accessed April 24, 2012.
14. Clive Oppenheimer. Climatic, environmental and human consequence of the largest known
historic eruption: Tambora volcano (Indonesia) 1815. Progress in Physical Geography 2003 27:
230. DOI: 10.1191/0309133303pp379ra
15. Alvarez, et al. Extraterrestrial Caused for the Cretaceous-Tertiary Extinction. Science June 6,
1980: 1095-1108. DOI:10.1126/science.208.4448.1095.
16. World Wind Energy Association; World Wind Energy Report 2010; April 2011.
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