brief explanation of Wind Energy

1. Wind Power integration
PSTI
28.08.14

2. Synopsis
•Statistics
• Fundamentals
• Classification
• Integration techniques with grid
• Major Phases in the Wind project
• Scheduling and forecasting

3. World Wide Wind Generation
Year
Capacity
(MW)
Growth
(MW)
Growth
(%)
1995 4,800 - -
1996 6,100 1,300 27.1
1997 7,482 1,382 22.7
1998 9,670 2,188 29.3
1999 13,699 4,029 64.3
2000 18,040 4,341 31.7
2001 24,318 6,279 34.9
2002 31,184 6,866 28.3
2003 39,333 8,149 26.2
2004 47,661 8,329 21.2
2005 59,062 11,401 24
2006 74,174 15,112 25.6
2007 93,958 19,784 26.7
2008 121,246 27,289 29.1
2009 157,909 36,664 30.3
2010 194,558 36,649 23.3
2011 237,022 42,465 21.9
2012 282,683 45,661 19.3
2013 318,510 35,828 12.7

4. Top 10 countries
by nameplate wind power capacity
(2013 year-end)
Country
New 2013
Wind power total
capacity % world
total
capacity (MW) (MW)
World total 35,289 MW 318,105 MW 100%
China 16,088 91,412 28.7
United States 1,084 61,091 19.2
Germany 3,238 34,250 10.8
Spain 175 22,959 7.2
India 1,729 20,150 6.3
UK 1,883 10,531 3.3
Italy 444 8,552 2.7
France 631 8,254 2.6
Canada 1,599 7,803 2.5
Denmark 657 4,772 1.5

6. STATE WISE WIND INSTALLATIONS IN INDIA as on 31.04.14
State Mar-14 Mar-13 Mar-12 Mar-11 Mar-10 Mar-09
Tamil Nadu 7275.68 7,162.18 6,987.60 5904.4 4907 4304.5
Maharashtra 4064.95 3,021.85 2,733.30 2310.8 2078 1938.9
Gujarat 3447.28 3,174.58 2,966.30 2175.5 1864 1566.5
Rajasthan 2783.45 2,684.65 2,070.70 1524.8 1088 738.4
Karnataka 2323.85 2,135.15 1,933.50 1730 1473 1327.4
Andhra Pradesh 783.35 447.65 245.5 200.2 236 122.5
Madhya Pradesh 423.4 386 376.4 275.5 229 212.8
Kerala 35.1 35.1 35.1 32.8 28 27
Others 4.3 4.3 3.2 0 4 1.1
Total 21141.4 19,051.46 17365 14158 11807 10242.3

7. Total generation capacity is : 233,929.94 MW as on 31.12.13

8. Sources of renewable energy in India
as of December 2013, MNRE India

9. Renewal Energy Installed Capacity in India (as of 31 January 2014)
Installed capacity
(in MW)
Wind 20,298.83
Small Hydel Power Projects 3,774.15
Bagasse Cogeneration 2,512.88
Solar 2,208.36
Biomass Power & Gasification 1,285.60
Waste to Power 99.08
30,177.90
Type Technology
Grid Connected Power
Total - Grid Connected Power
Wind Portfolio is 8.68 % in the total generation capacity of country

10. Synopsis

11. Why Seasons

12. General circulation
The regions around equator, at 0° latitude
are heated more by the sun than the rest of
the globe. These hot areas are indicated in
the warm colours, red, orange and yellow
in this infrared picture of sea surface
temperatures (taken from a NASA satellite,
NOAA-7 in July 1984).
Hot air is lighter than cold air and will rise
into the sky until it reaches approximately
10 km (6 miles) altitude and will spread to
the North and the South. If the globe did
not rotate, the air would simply arrive at
the North Pole and the South Pole, sink
down, and return to the equator.
The power emission from the
sun is 1.37 kW/m 2 on the
surface of the sphere, which
has the sun as its centre and
the average radius of the earth
trajectory. The power hits a
circular disc with an area of
of 1.27 x 10 14 m 2 . The
power emitted to the earth is
thus 1.74 x 10 17W.

13. Secondary Circulation
The wind rises from the equator and moves north and south in the higher layers
of the atmosphere.
Around 30°; latitude in both hemispheres the Coriolis force prevents the air from
moving much farther. At this latitude there is a high pressure area, as the air
begins sinking down again.
As the wind rises from the equator there will be a low pressure area close to
ground level attracting winds from the North and South.
At the Poles, there will be high pressure due to the
cooling of the air.
Keeping in mind the bending force of the Coriolis
force, we thus have the following general results for
the prevailing wind direction:
Latitude: 90-60°N 60-30°N 30-0°N 0-30°S 30-60°S 60-90°S
Direction: NE SW NE SE NW SE

14. Tertiary Circulations
Land masses are heated by the sun more quickly than the sea in
the daytime. The air rises, flows out to the sea, and creates a low
pressure at ground level which attracts the cool air from the sea.
This is called a sea breeze. At nightfall there is often a period of
calm when land and sea temperatures are equal.
At night the wind blows in the opposite direction. The land
breeze at night generally has lower wind speeds, because the
temperature difference between land and sea is smaller at night.
The monsoon known from South-East Asia is in reality a large-scale
form of the sea breeze and land breeze, varying in its
direction between seasons, because land masses are heated or
cooled more quickly than the sea.
Sea Breezes

15. Mountain winds
Mountain regions display many interesting weather patterns. One example is the valley
wind which originates on south-facing slopes (north-facing in the southern hemisphere).
When the slopes and the neighboring air are heated the density of the air decreases, and
the air ascends towards the top following the surface of the slope. At night the wind
direction is reversed, and turns into a down slope wind.
If the valley floor is sloped, the air may move down or up the valley, as a canyon wind.
Winds flowing down the leeward sides of mountains can be quite powerful:

17. Site / WTG Classification
Wind Class/Turbulence
Annual average wind speed at
hub-height(m/s)
Extreme 50-year gust in
meters/second (miles/hour)
I A High wind - Higher Turbulence 18% 10.0 70 (156)
I B High wind - Lower Turbulence 16% 10.0 70 (156)
II A Medium wind - Higher Turbulence 18% 8.5 59.5 (133)
II B Medium wind - Lower Turbulence 16% 8.5 59.5 (133)
III A Low wind - Higher Turbulence 18% 7.5 52.5 (117)
III B Low wind - Lower Turbulence 16% 7.5 52.5 (117)
IV 6.0 42.0 (94)

18. Wind Power Conversion technologies
• There is a kinetic energy in the moving air. That is Wind
• P = ½ rAV3Cp
Where P = the power of the wind measured in W (Watt).
r = (rho) = the density of dry air = 1.225 measured in kg/m 3 (kilograms per cubic meter, at average atmospheric
pressure at sea level at 15° C).
v = the velocity of the wind measured in m/s (meters per second).
A= Area of the turbine in Square meters
Cp = Conversion Factor (or) Efficiency of the turbine
• The mechanical device which converts this kinetic energy to Mechanical
rotational energy is called Turbine

19. BETZ Limit
The lower the value of V2, the more energy extracted by the wind
turbine, the more is the efficiency.
So if V2 =0 , do we produce maximum power?
Max Theoretical Efficiency= 59% when V2/V1=1/3

20. Nacelle
Tower
Hub
Blade

21. Operation of WTG

22. Synopsis

23. Classification of turbines By Mechanical features
Turbine
direction
Vertical Horizontal
Wind
direction
UP
Wind
DOWN
Wind
Number of
blades
TWO
Blade
THREE
Blade

24. Vertical Axis Wind Turbines Downwind Machines
Two-Bladed

25. Classification of turbines By Mechanical features
Turbine
regulation
PITCH STALL
BREAKING
Aerodynamic Mechanical
Tower
Tubular Lattice

26. Regulation
PITCH Regulation STALL Regulation

27. Generators
Wind
Generators
Synchronous
WRSG PMSG
Asynchronous
WRIG
DFIG Flexi Slip
SCIG
Single Speed Dual Speed

28. Synopsis

29. Generators - Asynchronous
Advantages:
1) These generators are nothing but the induction Motors
2) Very simple mechanism
3) There is no need of huge synchronizing and excitation
circuits
Disadvantages:
1) Draws inductive reactance from
grid causing low power factor
2) Requires power factor
correction circuit and Capacitors
3) Huge wear and tear

30. Induction generator

33. Flexi Slip System WRIG

34. Induction Generator - DFIG

35. Generators - Synchronous
Advantages:
1) These generators can generate their own VAR
2) By changing excitation we can generate the power at leading
or lagging. No need of power factor correction capacitors
3) Wind mills with synchronous generators will have lesser cut-in
wind speed (they can generate power at low wind speed
also)
4) There is no need of huge gear boxes
5) In certain cases the Wind mills can be operated as stand
alone system of generation
Disadvantages:
1) These generators requires huge power electronic
support
2) Requires very sophisticated controls

36. The gear concept and gearless concept in a component
comparison
Main Shaft
Hub
Rotor Shaft
Bearings
Clutch
Gear Brake
Generator
Generator Rotor
Generator Stator
Hub
Main Bearing
Axle pin
Conventional Gearless

37. Typical Synchronous Wind Energy Converter Block Diagram

38. Power Block Diagram

39. Synopsis

40. Major Phases of the project

41. Wind Resourcing and Assessing
• wind mast with 2 sets of Anemometers & wind vanes at
different heights will be erected at the prospective site.
• Height of wind mast will be depending up of the class of the
site
• Wind Speed, Wind direction, Temperature and Pressure are
measured
• Measurement Period:
– In general : Minimum of 1 year!
– 3 to 5 years is ideal for better estimation of wind
climate prevailing at the site
Analysis of measured wind data will be the key to
• Select wind turbine type based on wind
resource
• Design wind farm layout based on site
conditions
• Calculate energy output

42. Key – outputs of WRA
REV07, 05-03-2014
Probability of
Exceedence
PLF(%)
P50 30.00
P75 26.78
P90 23.87
Vagarai Monthly % Distribution
Apr 2.7%
May 7.8%
Jun 18.4%
Jul 20.5%
Aug 18.1%
Sep 14.9%
Oct 2.4%
Nov 1.9%
Dec 2.1%
Jan 3.6%
Feb 4.6%
Mar 3.1%
Total 100.00%
Wind
rose

43. WRA –micrositing

44. Access Roads and Power Evacuation

46. Construction Activities
BAR BENDING AND CENTERING
WORK.

47. CONCRETE FILLING IN TO THE FOUNDATION.

48. FINAL LOOK OF THE FOUNDATION.

49. Receipt of tower
sections
Unloading the
tower sections

50. Receiving the machine
and unloading

51. Blades receipt
and unloading

54. Nacelle
Tower
Hub
Blade

55. Synopsis

56. The epicenter of this report is to deal with the issues and challenges facing by all the stakeholders under this mechanism and aimed to provide a thought process for resolving
the difficulties aroused because of this mechanism in the sector.
in MW in %
Total Installed
Capacity
233930 100
Renewable
capacity Installed
29989 12.82
Wind 20149 8.61
Solar 2180 0.93
India is a rapidly growing economy which needs energy to meet its growth objectives in a
sustainable manner. The power generation from non-conventional sources like Wind and Solar
is an integral part of the energy system. The generation from wind and solar is depends upon
the nature with a benefit of being a clean energy source and a challenge of being an infirm
source of generation and to predict the generation for optimal management of electricity grid
increases manifold.
Indian Electricity Grid Code (IEGC) Regulation 2010 which was announced on 28th Apr 2010
identified this challenge. Origin of Forecasting & Scheduling of Wind and Solar power has
come through IEGC 2010 and introduced in the form of commercial implication mechanism
known as Renewable Regulatory Fund (RRF) which becomes the prime focus for the
Regulators.
Objective of IEGC to brings together:
- A single set of technical and commercial rules,
- Facilitation of the optimal operation of the grid,
- Facilitation for functioning of power markets,
- Facilitation of the development of renewable energy sources by specifying the technical and commercial aspects for
integration of these resources into the grid.
Instead of following the objectives first, the main focus moved towards the procedural implementation of RRF mechanism without understanding the facts of
technical and operational know-hows. The installation falls under RRF for forecasting and scheduling as per CERC order dated 16.01.2013 is not even 1% of
total installed capacity in the country.
“Does ensuing the 1% of wind/solar generation out of total installed capacity is the real motive?”
Answer is no…
Backdrop of RRF Mechanism

57. IEGC 2010
IWEA AND CERC PETITION - TASK
NLDC - DETAILED RRF PROCEDURE
SLDCS TO SUBMIT MOCK
EXERCISE DATA
FORCE FORMED
TASK FORCE SUBMITTED REPORT
TO CERC
COORDINATING AGENCY/
REFERENCE RATE INTRODUCED BY
CERC
CERC ACCORDED DETAILED RRF
PROCEDURE
NLDC - DRAFT DETAILED RRF
PROCEDURE
…. FILED APPEAL IN CHENNAI
RRF STARTED
HIGH COURT - MATTER
RRF COMMERCIAL MECHNAISM
SUSPENDED TILL FURTHER ORDERS
….FILED APPEAL IN DELHI HIGH
COURT
28th Apr
2010
18th Feb
2011
30th Nov
2011
27th Mar
2012
04th Sep
2012
16th Jan
2013
12th Jun
2013
09th Jul
2013
15th Jul
2013
07th Jan
2014
DATE MILESTONE
28th Apr 2010 IEGC 2010
18th Feb 2011 NLDC - Detailed RRF Procedure
30th Nov 2011 SLDCs to submit mock exercise data
27th Mar 2012 IWEA and CERC Petition - Task force formed
04th Sep 2012 Task force submitted report to CERC
16th Jan 2013 Coordinating Agency/ Reference Rate introduced by CERC
DATE MILESTONE
12th Jun 2013 NLDC - Draft Detailed RRF Procedure
09th Jul 2013 CERC accorded Detailed RRF Procedure
15th Jul 2013 RRF started
… . Filed appeal in Chennai High Court - Matter
… .Filed appeal in Delhi high Court
07th Jan 2014 RRF Commercial Mechnaism suspended till further orders
RRF Timeline

58. Commercial Settlement Overview
Dev %
range
0 - 30 30 - 50 > 50 -30 - 0 < -30
0 – 30 yes - - - -
30 – 50 yes yes - - -
> 50 yes yes yes - -
-30 – 0 - - - yes -
< -30 - - - yes yes
Dev %
range
0 - 30 30 -50 > 50 -30 - 0 < -30
0 – 30 A - - - -
30 – 50 A B - - -
> 50 A B C - -
-30 – 0 - - - A -
< -30 - - - A B
Commercial
Settlement
• A. PPA rate – settled by Utility
• B. PPA rate – settled by Utility + UI charges w.r.t. frequency settled through RRF
• C. UI @ 50 Hz – settled through RRF

59. Wind Power Scheduling Challenges
Wind Power Forecasting
Communicate forecasted and
actual data with SLDC
Adaptation of “Availability based tariff”
Liability of inaccurate forecasts
• Wind power forecast technology is
not advanced.
• Forecast does not meet the
required accuracy limits.
• Security issues in data
communication
• Installation of ABT meters at
pooling stations
• Most plants in rural areas
• Will make the existing projects
signed under PT and APPC + REC
unviable.
• Will adversely effect the growth of
wind industry in India.
• No forecasting agency or
coordinating agency promises
accurate forecast.

60. Thank you