Presentation 11.9.2013 at Jordan University, Amman

1. WIND ENERGY TECHNOLOGY
&
Application of Remote Sensing
Siraj Ahmed
Professor & Head
Department of Mechanical Engineering
MANIT Bhopal, India
GCREEDER 2013
11 September

2. Contents
 Introduction
 Wind Resource
 Site Characterization
 Wind Turbines
 Energy Calculations
 Optimization Opportunities
 Challenges of Integration

3. ………….Contents
 Re Powering
 Current Research Areas
 WRA & Remote Sensing
 Siting
 Environmental Impact
 Economics
 Wind Farm Development Steps

4.  Wind is air in motion
 Earth is tilted 23 1/2o of its axis to plane of rotation
results in Differential Heating from sun and causes
pressure difference on earth
 Rotation of Earth
 Geographical factors: global as well as local
 Kinetic Energy in Wind around the Globe is about
0.7x1021 J
What causes wind?

5.  Fuel is wind
 Less than 2% of land area is needed
 Wind turbines design life is 20-25 years
 Turbines are modular and quick to install for rapid
increase in generation
 Require no water
 Boost to regional economy, employment
Wind Energy

6. Wind Energy
 Arrests Climate Change, Global Warming
 Complements other sources during high wind
 Conserve fossil fuels
 Significant role in overall energy mix
 Perennial Energy Resource

7. Wind is air in motion
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Wind Vector
Steady Value
Fluctuating Value

8.  Stochastic in Nature
 Apart from the seasonal and daily
variations, the wind pattern may change
from year to year, even to the extent of
10 to 30 per cent

9. Wind Power Density (WPD)
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VAVP 
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VWPD 
Truer Indication
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WPD
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10. Wind Rose

11. Frequency
Cumulative time the wind blows at
prescribed values of velocity on an annual
basis
Persistence
Continuous time the wind maintains a particular
speed

12. Typical Wind Rose and Frequency
Distribution for a Site

13. Vertical Profile

14. Turbulence
 Rapid disturbances in wind speed, direction, and
vertical component
 Turbulence Intensity (TI)
V
TI


Relative Indicator
Low, Medium or High Levels on Different Sites
 = Standard Deviation
V = Mean Wind Speed

15. Wind Resource
Main Parameters
 Annual average wind speed (Uave)
 Wind Power Density (WPD)
 Wind Rose
 Wind Resource Map
 Prevailing Wind Direction
 Speed Frequency Distribution and
Persistence

16. Wind Resource
 Vertical Wind Speed Profile
 Wind Shear Exponent ()
 Weibull Parameters: Shape Parameter (k)
and Scale Parameter (c)
 Turbulence Intensity (TI)
 Wind Density () and its Variation Vertically
and Seasonally
 Historical Wind Data (including Fequency and
Intensity of Storms)

17. Site Characterization
 Longitude, Latidute, Average Mean Sea Level
 Available Land Area, Soil Type
 Positions of Existing Roads and Dwellings
 Type of Land Cover (e.g. Forests, Desert etc.)
 Political/Administrative Boundaries
 National Parks, Forest Reserves, Restricted Areas
 Proximity to Transmission Lines
 Location of Obstructions
 Potential Impact on Local Aesthetics
 Cellular Phone Service for Remote Data Transfers

18. Topographic Screening
Ridges oriented
perpendicular to the
prevailing wind direction
Highest Elevations
within a given
area
Locations where
Local Wind can
Funnel

19. Other Associated Parameters
 Power Curve of Turbine
 Capacity Factor (CF)
 Annual Energy Production (AEP)
 Economics
 Topographical Map, Contour Map
 Roughness Class of the Site
 Grid Related Studies
 Transmission Line Map
 Approach Road
 Other Infrastructural Facilities

20. Wind Turbines
Small (10 kW)
• Homes (Grid-connected)
• Farms
• Remote Applications
(e.g. Battery Changing, Water
Pumping, Telecom Sites)
Intermediate
(10- 500 kW)
• Village Power
• Hybrid Systems
• Distributed
Power
Large (500 kW – 6 MW)
• Central Station Wind Farms
• Distributed Power
• Offshore Wind

21. Wind Turbine
Horizontal Axis Wind Turbine Vertical Axis Wind Turbine

22. Energy Calculation
 Wind Kinetic Energy:
 Wind Power:
 Electrical Power:
 Cb  0.35 <0.593 “Betz limit”
 Ng  0.75 generator efficiency
 Nt  0.95 transmission efficiency
2
2
1
vmE airk 
32
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vrP airwind 
windtgbgenerated PNNCP 

23. Wind V and E Match

24. Optimization Opportunities
 Site selection
 Altitude, Wind Frequency, Consistency, Grid Access, etc
 Turbine Selection
 Design (HAWTs vs VAWTs), vendor, size, quantity,
 Turbine Height: “7th root law”
 Greater precision for local conditions
 Local topography (hills, ridges, …)
 Turbulence caused by other turbines
 Prevailing wind direction, wind rose, Turbulence Intensity
 Ground stability (support massive turbines)
 Grid upgrades: extensions, surge capacity, …
 Non-power constraints/preferences
 Environmental (birds, aesthetics, power lines, …)
 Cause radar clutter (e.g. near airports, air bases)
7
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v
v
g
h


25. Economic Optimization
 MW Capacity
 Questions
 Economy of scale?
 Life?
 Interest rate?
 Operational costs?
 Price of Storage or Battery Bank
 Price of Electricity

26. Optimization To Date
 Turbine Blade Design
 Huge Literature
 Generators
 Already near Optimal
 Wind Farm Layout
 Modeling & Simulation
 Topography
 Alternative Site
 + Transmission
 + Storage
New
Challenges

27. Challenges of Grid Integration
 Growth of Wind Power: Challenge for Utilities
and Grid Managers
 Intermittent Electricity
 Challenge: Integrating Large Variable Power
 Expected to Ride Through Disturbances
 Increased Transmission Capacity

28. How Wind Power is being Reliably
and Cost-Effectively Integrated?
 Advanced Turbine Technology
 Forecasting Techniques based on Probabilistic
Models
 Predicting Wind Power Output Hours and Days in
Advance with Increasing Accuracy and Confidence
 Spread Wind Farms in Larger Geographical
Regions

29. Re Powering
 Replacing Older, Less Efficient Turbines with
a Smaller Number of More Adavancd Models
 Re Power where the wind farm is
commissioned in last fifteen years or more
 Old Turbines can be Refurbished for Re-use

30. Current Research Areas
•Integration of Wind Turbines with Large Buildings
•Forecasting Model, Short and Long Term
•Penetration Limits in Grid
•System Integration of Wind Farms
•Lightning Protection of Blade and Tower Structure
•Nano-Composite Materials for Blade in different
Environmental Conditions
•Numerical & Observed Wind Atlas – Modeling,
Verification & Application

31. ….Current Research Areas
•Stand-Alone and Non-Grid Applications
•Wind – Solar Hybrid Systems
•VAWT – Aerodynamic Studies of Different
Configurations
•Offshore – Foundation, Cable & Peculiar Issues
of Marine Operation
•Repowering, Techno-Economic Analysis
• Wind Farm Design and Flow Modelling
•Smart Grid, Net Metering ………………..

32. Off-Shore Development
• Pressure of Space
• Greater Productivity from a Better Wind Regime
• Stronger Foundations
• Long under Water Cables
• Larger Individual urbines.

33. Wind Resource
Assessment &
Remote Sensing (RS)
Techniques

34. Anemometry ?
Study of measuring,recording and analysing
the direction and speed of the wind

35. Objectives of Anemometry
► Wind speed
► Wind direction
► Air temperature
► Barometric pressure
► Precipitation
Finally, Assessing the Power in the flow of wind.
31
2
P A V

36. Steps in anemometry
 Setting up a wind-monitoring tower
 Installing sensors at different heights
 Installing data logger and programming
 Collection & Recording of time-series data
 Analysis of Recorded data

39. Typical Wind Monitoring Station

40. Remote Sensing Techniques
 SODAR Sound Detection and Ranging
 LIDAR Light Detection and Ranging

42. Applications of RS Techniques
 Wind Resource Mapping
 Wind Profiling (Vertically and horizontally)
 Wind Scanning (In a plane and in a volume)
 Power Curve Verification
 Determination of Wind Loads
 Wind Turbine Control (Feed Forward Control)

43. Important Issues
 Remote Sensing Applications
On-Shore and Off-Shore
 Size & Hub Height are increasing (Design Stage)
Example:10 MW, Rotor Diameter 180 m
Hub Height of 165 m
 Meteorological towers are very expensive above
100 m height.

44. Important Issues
 Meteorological towers measures wind
characteristics at a point but Remote sensing
measures in a volume of space.
 Remote sensing can measure temperature
profile very effectvely.
 Cup anemometer (reference instrument) data
and lidar recorded data show closeness with
in 1 percent.

45.  Studies of mixing layer height in the
atmospheric boundary layer is very important
due to low level jet effects at different times of
the day due to synoptic situation changes in
12 hours period.
For Example the difference in wind shear
profile above and below 160 m level is
significant for multi-MW wind turbine.
Important Issues

46.  Temperature inversion in the atmosphere
affects back scatter.
 Usually maximum output of a wind farm is
occuring at night time as compared to day
time due to lower level of turbulence. It offers
integration of solar photo voltaic energy in
existing wind farms to normalise the
difference in output.
 Sodar technique can be used for
measurement in the range of 200 m to 600 m
and lidar technique can be used upto 2000 m.
Important Issues

47.  By using pulsed coherent lidars for remote
sensing of wind the measurement is
performed in the slice of atmosphere
instead of a point.
 Lidar offers power curve verification of
wind turbines through remote sensing.
 Buoy and floating plateform mounted
lidars are useful for off shore applications.
Important Issues

48.  Wind scanner can be used for pro-active control
of wind turbine.
For Example nacelle mounted lidras can sense
approaching wind front say at 300 m ahead of
rotor. By the time the wind front strikes the rotor,
the blade pitching takes place to optimum angle.
The feed forward control of wind turbine is thus
achieved.
Important Issues

49.  Concept of Rotor Equivalent Wind Speed
(REWS) is more realistic than hub height
single point reference wind speed for power
curve verification as well as for assessment
and quantification of kinetic energy in wind.
Important Issues

50.  Lidar/Sodar is used with a met mast for
initialization and calibration for measuring
wind characteristics even upto the tip of blade
in vertical position.
 Even 1 percent inaccuracy in wind resource
measurement over a period of one year leads
to substantial generation revenue loss for
1 MW wind turbine due to cubic relationship.
Important Issues

51.  For Off-Shore application sea-state
instrumentation is required which is costlier
and sophisticated than normal
instrumentation.
Important Issues

52. Siting
Wind Farm Layout

53. MICRO-SITING
Art of positioning Wind Turbines in a Wind-Farm for
Maximizing its Annual Energy Production (AEP)
Based on
1. Wind Characteristic Parametrs
2. Wind Turbine Parameters
3. Site Parameters

54. Typical Layout
 Turbine Spacing 7
times diameter in
prevailing wind
direction.
 Turbine Spacing 4
times diameter
perpendicular to wind
direction.

55. Wind Farm

56. Environmental Impact
 Mechanical Noise: Gear-Box, Generator
 Aerodynamic Noise: Swishing Sound
 Wind-Farm at 350 m away
Noise level dB(A) 35-45
 Electromagnetic Interference
 Visual Impact
 Shadow Flicker
 Ecology, Avian Casualty

57. ECONOMICS
 Annual Energy Production
 Capital Cost
 Interest Rate
 Pay-Back Period
 Operation & Maintenance Cost, Insurance, Land-Lease etc.
 Life Cycle Cost Analysis
ANNUAL ENERGY PRODUCTION DEPENDS
 Wind Speed Power Curve of Wind Turbine
 Wind Speed Frequency Distribution of Site
 Availability of Wind Turbine

59. Steps of Development
 Analyze the Wind Resource
 Conduct Site Analysis
 Establish Economics of the Project
 Analyze Critical Environmental Issues
 Identify Regulatory Frame Work
 Conduct Transmission Capacity Analysis

60. …….Steps of Development
 Master Plan Approach (Futuristic)
 Maximize Energy Capture
 Reduce Unit Cost of Generating Electricity
 Re-powering