Among the Renewable Energy Sources, Wind Energy is taken up with careful prior efforts before implementation as it requires all capital and technical inputs before payback starts. However, it is a clean source of electric power compared to coal based thermal power. India is a country that has made progress in wind power investment.

1. Turbine Photo Source: http://www.skystreamenergy.com/skystream-info/productphotos.php

2. U b Pl i
Renewable Energy Projects in Action
Wind Power
Fundamentals

7. A
Kinetic Energy
Thus:
Fundamental Equation of Wind Power
A
v
mass flux– Power is KE per unit time:
dt
• dm/dt = ρ* A * v
Thus:– • Power ~ cube of velocity
•
•
Power ~ air density
Power ~ rotor swept area A= πr 2
v 3• P = ½ * ρ * A *
– Wind Power depends on:
• amount of air (volume)
• speed of air (velocity)
• mass of air (density)
flowing through the area of interest (flux)
– Kinetic Energy definition:
• KE = ½ * m * v 2
m& dm
• P = ½ * m& * v 2
– Fluid mechanics gives mass flow rate
(density * volume flux):

8. Efficiency in Extracting Wind Power
extracted by
= PT/PW
the turbine
16/27
nd turbine can do in
Betz Limit & Power Coefficient:
• Power Coefficient, Cp, is the ratio of power
to the total contained in the wind res urce Cp
• Turbine power output
PT = ½ * ρ * A * v 3 * Cp
• The Betz Limit is the maximal possible Cp =
• 59% efficiency is the BEST a conventional wi
extracting power from the wind

17. •
Wind types
•
•
Tornadoes
Gusts / Dust devils / Microbursts
•
•
Nocturnal Jets
Atmospheric Waves
• Planetary circulations:
– Jet stream
– Trade winds
– Polar jets
• Geostrophic winds
• Thermal winds
• Gradient winds
• Katabatic / Anabatic winds – topographic winds
• Bora / Foehn / Chinook – downslope wind storms
• Sea Breeze / Land Breeze
• Convective storms / Downdrafts
• Hurricanes/ Typhoons

32. Wind Turbine Types
Photos courtesy of Steve Connors, MITEI
Horizontal-Axis – HAWT
• Single to many blades - 2, 3 most efficient
• Upwind, downwind facing
• Solidity / Aspect Ratio – speed and torque
• Shrouded / Ducted – Diffuser Augmented
Wind Turbine (DAWT)
Vertical-Axis – VAWT
• Darrieus / Egg-Beater (lift force driven)
• Savonius (drag force driven)

42. Wind Turbine Blades
Systems
Hubs:
and
http://guidedtour.windpower.org/en/tour/wres/index.htm
• Blade tip speed:
• 2-Blade
Teetered
Pitch
control:

64. Fundamentals of Wind Power …Wind Power Fundamentals …

65. A
Kinetic Energy
Thus:
Fundamental Equation of Wind Power
A
v
mass flux– Power is KE per unit time:
dt
• dm/dt = ρ* A * v
Thus:– • Power ~ cube of velocity
•
•
Power ~ air density
Power ~ rotor swept area A= πr 2
v 3• P = ½ * ρ * A *
– Wind Power depends on:
• amount of air (volume)
• speed of air (velocity)
• mass of air (density)
flowing through the area of interest (flux)
– Kinetic Energy definition:
• KE = ½ * m * v 2
m& dm
• P = ½ * m& * v 2
– Fluid mechanics gives mass flow rate
(density * volume flux):

66. Efficiency in Extracting Wind Power
extracted by
= PT/PW
the turbine
16/27
nd turbine can do in
Betz Limit & Power Coefficient:
• Power Coefficient, Cp, is the ratio of power
to the total contained in the wind res urce Cp
• Turbine power output
PT = ½ * ρ * A * v 3 * Cp
• The Betz Limit is the maximal possible Cp =
• 59% efficiency is the BEST a conventional wi
extracting power from the wind

67. 0.12
0.1
0.08
0.06
0.04
0.02
0
1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0- - - - - - - -<
Power Curve of Wind Turbine
is operating at
ut ≈ 30%
turbine and the
good site)
windspeed(m/s)
Distribution
Capacity Factor (CF):
• The fraction of the year the turbine generator
rated (peak) power
Capacity Factor = Average Output / Peak Outp
• CF is based on both the characteristics of the
site characteristics (typically 0.3 or above for a
Power Curve of 1500 kW Turbine Wind Frequency
Nameplate

68. Lift and Drag Forces

69. Wind Power Technology …

70. Diagnostics
Wind Turbine Subsystems
–
–
Cooling
Diagnostics
– Foundation
– Tower
– Nacelle
– Hub & Rotor
– Drivetrain
– Gearbox
– Generator
– Electronics & Controls
– Yaw
– Pitch
– Braking
– Power Electronics

71. Foundations and Tower
monopole towers
for offshore

72. 6
methods to determine optimum
blade shape
Nacelle, Rotor & Hub
attack, lift and drag characteristics
Combine with theory or empirical6.
Main Rotor Design Method (ideal
case):
1. Determine basic configuration:
orientation and blade number
2 take site wind speed and desired
power output
3 Calculate rotor diameter (accounting
for efficiency losses)
4. Select tip-speed ratio (higher 
more complex airfoils, noise) and
blade number (higher efficiency with
more blades)
5. Design blade including angle of

73. Hi t i ll hi h t ( f
Electrical Generator
Generator
als)
–
–
Slip (operation above/below synchronous speed)
Reduces gearbox wear
Masters, Gilbert, Renewable and Efficient Electric Power Systems, Wiley-IEEE Press, 2003
http://guidedtour.windpower.org/en/tour/wtrb/genpoles.htm .
possible
• Generator:
– Rotating magnetic field induces current
• Synchronous / Permanent Magnet
– Potential use without gearbox
– Historically higher cost (use of rare-earth met
• Asynchronous / Induction Generator

74. control low
Control Systems & Electronics
with wind speed to actively
control low-speed shaft for a
more clean power curve
• Control methods
– Drivetrain Speed
• Fixed (direct grid connection) and
Variable (power electronics for
indirect grid connection)
– Blade Regulation
• Stall – blade position fixed, angle
of attack increases with wind
speed until stall occurs behind
blade
• Pitch – blade position changes

75. Wind Grid Integration
error
research:
rastructure,
Advanced
Controls
air, batteries,
-grid (V2G)
Wind Forecast
Real WindProduction
500
0
400
0
300
0 Time 23-24/01/2009
Left graphic courtesy of ERCOT
Right graphic courtesy of RED Electrica de Espana
WindProductioninMW
Wind Market Program
• Short-term fluctuations and forecast
• Potential solutions undergoing
– Grid Integration: Transmission Inf
Demand-Side Management and
– Storage: flywheels, compressed
pumped-hydro, hydrogen, vehicle-2
12000
11000
10000
9000
8000
7000
6000

76. Future Technology Development
superconducting
control methods
designs
materials, direct
maintenance
• Improving Performance:
– Capacity: higher heights, larger blades,
magnets
– Capacity Factor: higher heights, advanced
(individual pitch, smart-blades), site-specific
• Reducing Costs:
– Weight reduction: 2-blade designs, advanced
drive systems
– Offshore wind: foundations, construction and

77. Future Technology Development
materials, preemptive
ude concepts
Windpower
• Improving Reliability and Availability:
– Forecasting tools (technology and models)
– Dealing with system loads
• Advanced control methods,
diagnostics and maintenance
– Direct drive – complete removal of gearbox
• Novel designs:
– Shrouded, floating, direct drive, and high-altit
Sky

78. Going Beyond the Science &
Technology of Wind…
Source: EWEA, 2009

79. % Cost Share of 5 MW Turbine Components
Source: EWEA, 2009, citing Wind Direction, Jan/Feb, 2007

80. The Environment
ts,
effects
Natural Resources Defense Council,
World Wildlife Fund support wind power
projects like Cape Wind
Graphic Source: Elsam Engineering and Enegi and Danish Energy Agency
• Cleaner air -- reduced GHGs, particulates/pollutan
waste; minimized opportunity for oil spills, natural
gas/nuclear plant leakage; more sustainable
• Planning related to wildlife migration and habitats
• Life cycle impacts of wind power relative
to other energy sources
• Some of the most extensive monitoring
has been done in Denmark
– finding post-installation benefits
• Groups like Mass Audubon,

81. Wind energy is a mainstream,
competitive and reliable power
technology. Globally, progress
is strong, with more active
countries and players, and
increasing annual installed
capacity and investments.
Technology improvements have
reduced energy costs, on land.
The industry has overcome
supply bottlenecks and
expanded supply chains.

82. Since 2008, wind power deployment has more
than doubled, approaching 300 gigawatts (GW)
of cumulative installed capacities, led by China
(75 GW), the United States (60 GW) and
Germany (31 GW). Wind power now provides
2.5% of global electricity demand – and up to
30% in Denmark, 20% in Portugal and 18% in
Spain. Policy support has been instrumental in
stimulating this tremendous growth.

83. Wind power entails no direct greenhouse gas
(GHG) emissions and does not emit other
pollutants (such as oxides of sulphur and
nitrogen); additionally, it consumes no water. As
local air pollution and extensive use of fresh
water for cooling of thermal power plants are
becoming serious concerns in hot or dry
regions, these benefits of wind become
increasingly important

84. Wind energy, like other power technologies based on
renewable resources, is widely available throughout
the world and can contribute to reduced energy
import dependence. As it entails no fuel price risk or
constraints, it also improves security of supply. Wind
power enhances energy diversity and hedges against
price volatility of fossil fuels, thus stabilizing costs of
electricity generation in the long term.