Wind Energy
Ally Keefe, Dave Mccabe, Geoff
Frazier, Ryan Whalen, Meghan Moroni,
Jeb Stuart, Brianna Parke, Peter
Virchick
General Info
• Wind constitutes less than 3% of US
energy sources.
• Many say wind has the power to add more
to US generating capacity than coal in the
next 20 years.
• North Dakota, Kansas, and Texas alone
have enough harnessable wind to meet
national electricity needs.
History of Wind Power
• Wind power evolved from the use of simple, light
devices driven by aerodynamic forces to heavier
drag devices and finally to light, more efficient
lifts.
• The sailboat is the earliest known use of wind
power.
• The first windmills were made to automate the
tasks of grain grinding and water pumping in
Persia 500-900AD
Wind as Electricity
• The first use of a windmill to
generate electricity was in
Cleveland, Ohio in 1888 by
Charles F. Brush.
• In 1891, Dane Poul la Cour
made the first aerodynamically
(low solidity, four bladed)
designed system.
• By 1920, the la Cour system
replaced all previous sail and
fan systems.
Development of Wind Technology
-During the 1920’s modified propellers were used to drive direct current
generators.
-Bulk Power Wind Energy was first made in Russia in 1931 (100kw
Balaclava Wind Generator).
-The largest bulk wind energy producer was the Smith-Putnam
Machine (Installed in Vermont, 1941)
European and American
Involvement
• After WWII European
Countries developed
wind systems further
when fossil fuel shortages
led to high energy costs.
• US wind involvement
began after the 1973 oil
embargo. Beginning of
the US Federal Wind
Energy Program.
The Mechanics of a Wind
Turbine
Where Does the Wind Come
From?
• The wind is a by-product of
solar energy. Approximately
2% of the sun's energy
reaching the earth is
converted into wind energy.
The surface of the earth
heats and cools unevenly,
creating atmospheric
pressure zones that make
air flow from high- to lowpressure areas.
• Wind power is a measure of the energy
available in the wind. It is a function of the
cube (third power) of the wind speed. If the
wind speed is doubled, power in the wind
increases by a factor of eight (23). This
relationship means that small differences
in wind speed lead to large differences in
power.
Equation Of Wind Power
• The amount of power available in the wind is
determined by the equation:
• w = 1/2 r A v3
• w is power, r is air density, A is the rotor area,
and v is the wind speed. This equation states
that the power is equal to one-half, times the air
density, times the rotor area, times the cube of
the wind speed. Air density varies according to
elevation, temperature and weather fronts.
Vertical Axis Turbines
• Although vertical axis
wind turbines have
existed for centuries, they
are not as common as
their horizontal
counterparts. The main
reason for this is that they
do not take advantage of
the higher wind speeds at
higher elevations above
the ground as well as
horizontal axis turbines.
Horizontal Axis Turbine
• This is the most common
wind turbine design. In
addition to being parallel to
the ground, the axis of blade
rotation is parallel to the
wind flow. Some machines
are designed to operate in an
upwind mode, with the
blades upwind of the tower.
In this case, a tail vane is
usually used to keep the
blades facing into the wind.
Other designs operate in a
downwind mode so that the
wind passes the tower before
striking the blades.
• Rotor- The hub and the blades
together are referred to as the
rotor. Wind turns the blades
which turn the drive shaft.
• Shaft- Two different shafts turn
the generator. One is used for
low speeds while another is
used in high speeds.
• Gear Box- Gears connect the
high and low speed shafts and
increase the rotational speeds
from about 10-60 rotations per
minute to about 1200-1800 rpm,
the rotational speed required by
most generators to produce
power.
• Generator- The generator is what converts the turning
motion of a wind turbine's blades into electricity. Inside
this component, coils of wire are rotated in a magnetic
field to produce electricity. Different generator designs
produce either alternating current (AC) or direct
current (DC), and they are available in a large range of
output power ratings. The generator's rating, or size, is
dependent on the length of the wind turbine's blades
because more energy is captured by longer blades.
• Controller- Turns the blades on at 8-16 mph and shuts
them down around 65 to prevent any high wind
damage.
• Tower- Tall tubular metal shaft. The taller the tower,
the more power produced.
Pros of Wind Power
• Wind power Units are quickly
constructed.
• Wind generators are much smaller
in size compared other types
electrical generators.
• Small size allows wind power to be
very versatile.
• Wind power is a great compliment
to a house with a preexisting
photovoltaic system.
• Serves as a great backup system.
• Wind power gives off no harmful
emissions into the environment.
• It is a renewable
resource.
• The more time
spent researching
makes each new
wind turbine more
efficient.
• Mass production of
wind turbines
drives down costs.
Downfalls To Wind Energy
• Aesthetics – “Not in my back yard.”
• Inefficient and unreliable
• Hazard to bird migration
Aesthetics
• Turbines are around 50ft high and can be
seen for miles
• Wind Farms use up more space than any
other form of power plant
• Access roads will follow the construction of
a wind farm
• Houses too close to turbines will be
disturbed by their noise
“Not In My Back Yard”
Inefficient & Unreliable
• It is not uncommon for turbines to be hit by
lightning strikes. This can cause damage
to the turbine, and also provoke forest
fires.
• Propellers often fall off and are not
repaired – example -> Altamont area of
California
• Inefficient: 9,369 turbines only produce 1.7
% of Germany’s power
• No Wind = No Power
Some Stats on Contribution and Failure
Country
MW
windpowe
r
Wind
output
(GWh/y)
Total
output
(TWh/y)
Wind
contributi
on (%)
Denmark
2338
4240
35
Germany
6095
8400
486
1.73
76
817
0.009
12.1
Japan
121
UK
408
895
388
0.23
USA
2554
6000
3688
0.16
Failure Stats for Germany (2000)
FAULT % TURBINES AFFECTED
Loosening of parts-------3
Cause unknown----------8
Other causes------------10
High wind----------------4
Grid failure--------------6
Control system---------20
Icing---------------------1
Component failure---44
Lightning---------------4
Hazard To Bird Migration
• Turbines and power lines
and a danger to migrating
birds
• Proof:
- Wind Power Monthly
stated that large numbers
of several bird species
protected by European
Law have been killed by
turbines (1994)
- 200-300 Red Tail Hawks,
40-60 Golden Eagles are
killed each year by
turbines
- English nature stated
that habitat loss,
significant death to birds,
and changes in migratory
patterns are a result of
wind farms
Sources
Hinrichs, Kleinbach, Energy: Its Use and the Environment, 3rd ed. Thomson Learning,
Australia 2002.
Nigel Barnes, “An Ill Wind – An Objection Against Windfarms in Ireland.”
http://www.geocities.com/nigbarnes/#oth 3.28.04
www.windpowercons.com 3.28.04
What is the Cape Wind Project?
•Proposal for the first off shore wind farm in the United States
•130 turbines (24 square miles)
•maximum output=420 megawatts
Where will it be?
•Horseshoe Shoal, Nantucket
Sound, Massachusetts
•At least five miles off shore
•Strong, consistent winds and
shallow water
•Close to electrical
interconnections and away from
shipping lanes and boating
traffic
Pros of the Project
•Replaces 113 million tons of oil
per year
• “Zero-emissions”
•Boost to Cape Cod’s economy
-600-1,000 new jobs for
Cape Codders
•Does not require land
•May help with navigation and
rescue
Cons of the Project
•Private take over of public land
•May alter public use and access
•Decrease in property values
•No regulatory process to govern
project
•Potential hazard to wildlife
•Aesthetics of Cape Cod’s natural
landscape may be interrupted
Who are the major stakeholders?
•17 different government agencies
•United States Army Corps of Engineers (USACE)
•Massachusetts Environmental Protection Agency (MEPA)
•Clean Power Now
•The Alliance to Protect Nantucket Sound
United States Army Corps of Engineers
•Regulate water resources
•Seven Principles (2002)
•No regulatory framework or experience
•NEPA, EIS, and MEPA
•Public Interest Doctrine
•Scientific Monitoring Station
The Alliance vs. Clean Power Now
Supporters:
Supporters:
•The Kennedys
•U.S. Coast Guard
•Gov. Mitt Romney
•Walter Cronkite?
Argument:
Argument:
•navigation hazard
•help navigation
•blades will kill birds
•turbines are too slow
•interrupts whale migration
•Horseshoe Shoal is shallow
•there are other nearby options
•best location
Clean Power Now
Charley Cummings
(representative of the Brown
College Environmental
Action Network)
Protest outside of USACE meeting in
Falmouth, MA
Over 300
supporters
gathered in front
of the State
House!
The Alliance to Protect Nantucket Sound
State Rep. Demetrius
J. Atsalis and Sen.
Robert O’Leary
Susan Nickerson,
Director of the
Alliance
Cliff Caroll of
Wind Stop
Cape Wind’s Visual Simulations from Cotuit
6.0 miles off the coast
The Alliance’s Simulation from Cotuit
Websites to check out
www.capewind.org
www.cleanpowernow.org
www.saveoursound.org (The Alliance)
www.windstop.org