1. Due Diligence on Wind Energy Projects Site Assessment
30. October 2012, Ho Chi Minh City, Vietnam

2. 1) Introduction – Lahmeyer International GmbH 2) Site Assessment
Outline
1) Introduction – Lahmeyer International GmbH
2) Site Assessment
3) Bankability criteria
4) On-site wind measurement
5) Wind farm planning and layout
Distances
Turbulences
Turbine and site suitability
Environmental restriction
6) Wind studies
7) Norms and guidelines
8) Appendix

3. Lahmeyer International GmbH
Overview
Company Lahmeyer International GmbH (LI)
Founding Year 1966
Headquarter Bad Vilbel, Germany
Services Technical and economic planning and consulting services
Fields of Activity - Energy
- Hydropower and Water Resources
- Transportation
LI Group 6 Associated Companies
Employees LI Group: 1500
Turnover LI Group: 150 million Euro
Representatives in 50 Countries

4. Hydropower and Water Resources Division
Lahmeyer International GmbH
Divisions & Departments
Hydropower and Water Resources Division
Energy Division
Transportation
GE 1 – Electrical Engineering
Interdisciplinary technical advisor….
… covering the whole energy industry.
GE 2 – Transmission and Distribution
GE 3 – Privately Financed Projects
GE 4 – Thermal Power Plants
GE 5 – Renewable Energies I
GE 6 – Renewable Energies II – Wind Energy
GE 7 – Economics and Energy Efficiency

5. GE6 – Wind Energy Department

6. Global Presence LI has provided wind energy services in over
65 different countries around the world.

7. All our services are tailored to our Clients specific needs.
Consulting Services – Overview
Wind Potential Assessment
Feasibility Studies
Contractual Services
Due-Diligence Services
Market Analysis
Planning and Design
Financial & Economic Services
Construction Supervision
Operation & Maintenance Services
All our services are tailored to our Clients specific needs.

8. GE 6 – Wind Energy Division
Key References
Wind measurements masts installed > 240
Country wide wind mappings > 14 countries
Wind potential evaluations > 300 wind farms
CFD wind studies > 120 wind farms
Feasibility studies > 80 wind farms (> 3,300 MW)
Due diligence studies > 600 wind farms (>12,500 MW)
Construction supervision > 60 wind farms (> 1,700 MW)
Operation and maintenance supervision > 90 wind farms (> 2,800 MW)
CFD: Computal fluid dynamics

9. Example: Zafarana IV Wind Park, Egypt
GE 6 – Wind Energy Division
Example: Zafarana IV Wind Park, Egypt
Client
New and Renewable Energy Agency (NREA)
Main Data
Installed capacity: MW
Number of wind turbines:
Type of turbine: Gamesa: G52, 850 kW
Annual Energy Generation: GWh p.a.
Execution
Services
Implementation Plan
Tender procedure (incl. O&M Contract)
PPA and tariff elaboration
Construction Supervision
O&M Supervision
O&M: Bankers and Owner Engeneering
Supervision during Operation management: turbine inspection, Checking operation management, Training, Recommendation for technichal improvements

10. Example: Gangwon Wind Farm, Korea
GE 6 – Wind Energy Division
Example: Gangwon Wind Farm, Korea
Client
Unison Corporation, Korea
Main Data
Installed capacity: 98 MW
Number of wind turbines: 49
Type of turbine: Vestas V80 – 2.0MW
Annual Energy Generation: 244 GWh p.a.
Execution
Services
Project Management
Complete Planning and Engineering
Full-time Construction Supervision
Site Management
Commissioning
Quality Control and Assurance
O&M Supervision
Additional key data: The electricity output is 244GWh per year. For grid connection a new substation and a 154kV power line was constructed. The total length of the power line is 10.3km with 7.5km performed as overhead line and the remaining 2.8km as underground cable. The site is complex with an average elevation of 1,100m above sea level and access roads of totally 27.6km have been built. The full project cost including financing amount to 160 billion Korean Won, equivalent to about 154 million US Dollars.
The long project history goes back to year 2000 when our plans have been forwarded to the local province. In 2001 a MoU between Unison and Lahmeyer for the joint project development has been signed, the project company was founded in Korea and we completed the feasibility study for the project. Only in 2002 we got official information about the feed-in tariff. The rest of the year is straight-forward project development: Obtaining power license, clarifying issues with the Military radar, environmental impact, and land-lease agreements. Then two obstacles appeared: One is an aviation route marker in the vicinity, which required a comprehensive impact study by the specialist consultant NAVCOM and which required a re-routing of our power line. And second a part of the wind farm area is located in an area of national interest where any construction was prohibited until a new law made exemptions for renewable energies. Under this new law a 2nd environmental impact assessment was performed and finally the remaining part of the project was approved with one and half year delay. After that we could present the project to investors, prepare the information memorandum and mandate the bank arranger.

11. Example: Development of 3 Wind Farms in Sudan
GE 6 – Wind Energy Division
Example: Development of 3 Wind Farms in Sudan
Client
MINISTRY of ELECTRICITY AND DAMS (MED), SUDAN
Main Data
Planned capacity: 30 MW
Foreseen turbine type: 800 – 2,500 kW
Execution
Services
Update of Feasibility Studies:
Assessment of the available wind data
Wind farm siting
Energy yield calculation
Supervision of wind measurement campaign
Electrical and civil wind farm layout
Review of electrical conditions
Economical and financial analysis
Steering of CDM registration process
Design and Tendering
Preparation of Conceptual Design
Preparation of Tender Documents
Coordination of Tender process and contract negotiations
Construction supervision
Supervision of Construction
Acknowledging the huge potential for renewable energies in Sudan, the Ministry of Electricity and Dams of Sudan (MED) intends to develop renewable energy power projects in order to promote sustainable development. In the initial stage, MED has foreseen to focus on wind energy projects explicitly and awarded an owners engineering contract to Lahmeyer International (LI) for the forthcoming wind park projects.
The first three wind farms to be developed shall be located at Nyala (located in Darfour State in western Sudan) and Dongola (located in the north of Sudan) where on-site wind measurements have been performed in 2001 and 2002 by Lahmeyer International. Afterwards, feasibility studies have been prepared on basis of the wind turbine technology available at that time. A third project, which shall be located at the Red Sea Coast, shall be developed in the near future once a 12 months wind measurements campaign which shall start in April 2011 is completed. The planned capacity of the three projects are:
Nyala: MW
Dongola: MW
Red Sea Cost: 180 MW
For these projects, MED has engaged Lahmeyer International as its consultant. In the initial stage of the three projects, LI will review and update the former feasibility studies and will coordinate the wind measurements. Subsequently, the design and tender process will be initiated. According to MED, the projects shall be implemented as soon as possible. Thus, it is planned to select the turbine supplier in mid of 2011.

12. Example: Feasibility Study Wind Energy on Phu Quoc Island, Vietnam
GE 6 – Wind Energy Division
Example: Feasibility Study Wind Energy on Phu Quoc Island, Vietnam
Client
Electricity of Vietnam Power Company No.2
Main Data
2 existing Diesel power stations: 7 MW (total installed capacity) O/HFO fired generation (end 2005): 5 MW
Existing distribution network: OH; 22kV (MV); 0.4kV (LV)
Forecasted total demand by the end of 2010: 50 MW
Execution
Services
Phase II: Conceptual Design
Power demand analysis
Electrical grid qualitative analysis
Optimization of the wind farm layout
EIA and resettlement plan
Phase I: Feasibility Study
Wind Resource Assessment (Identification of the five most promising locations)
Site selection
Wind farm concept
Basic calculation of Specific Electricity Generation

13. Task of Site Assessment:
Measurement and analysis of wind conditions
Benefit: Early knowledge may save your money in case of too low wind conditions
Benefit: Knowledge about the risks, e.g. turbulences, extreme wind conditions
Annual energy production
Benefit: Allows you to calculated the profitability of your wind project (in case FIT is available) or to calculate the PPA
Wind farm layout and micro-siting
Benefit: Licensable layout, considering restrictions, e.g. environmental, setbacks towards roads, high voltage lines, railways, residents
Benefit: Choice of most suitable turbine
Environmental impact assessment
Benefit: Helps you to improve your layout in case results exceeds local laws
Country wide or area specific wind mapping
 Benefit: Know the hot spots

14. Goals of Site Assessment:
Knowledge about the wind conditions of your site
Wind speed
Wind direction
Turbulences
Extreme wind condition
Air density
Site suitability
Choice of right turbine type
Layout respecting restrictions
Bankable and reliable wind and energy study
Calculation of the income side and profitability

15. Bankability criteria Site Assessment
On-site wind measurements
Modelling with proper models, like WAsP for simple terrain and CFD for complex
Wind farm layout
Distances
Restrictions
Turbulence
Available land
Turbine suitability
Site suitability
Bankable wind resource and energy studies by independent consultants
Bankable is what a bank accepts, even if they deviate from norms, guidelines and common practice

16. On-site wind measurement
Why on-site measurement, instead of only modeling?
All models, regardless if static (WAsP) or dynamic (microscale CFD, meso scale atmospheric models) have inherent limitations. Especially extrapolation of wind speed to greater heights above ground is problematic and affected with high uncertainty.
Turbulence data and vertical profile at a complex site can only precisely be determined by measurement
Extreme wind speed calculation for turbine class assignment is more reliable with on site measured time series
Indispensable precondition for project financing
Additional data for temperature, humidity, pressure and solar radiation can be gathered
Reduction of uncertainty because of „real“ wind data
 lowers risk for banks and investors
 increasing of your project value

17. On-site wind measurement
Key requirements to wind measurements
Representative mast position
In complex terrain more than one mast
Measurement height minimum 2/3 of planned hub height
State-of-Art sensors
„First Class“ anemometers
Individually calibrated anemometers
Measurement of wind speed, wind direction, temperature
Optionally air pressure, humidity, flow inclination
Wind speed sensors (anemometer) at minimum three different levels; minimum distance 20 m
Wind direction at two heights
Mounting and mast design according to IEC Annex G
Measurement documentation according to Measnet
Minimum measurement period 1 year
Permanent monitoring during measurement to avoid major failures

18. On-site wind measurement
Quality of energy results stands or falls with the wind measurement
 More technical details in Annex

19. Wind Farm Planning and Layout
Defining site borders (land availability, etc.)
Site access (nearby roads, complexity of the site, etc.)
Exclusions areas (e.g. distance to suburban areas, houses, streets, etc.)
Wind Resource
Distances between the turbines
Respecting restrictions (e.g. noise, shadow flicker, animals)
Obstacles (Rivers, mountains, villages, roads, transmission lines and other obstacles)

20. Wind Farm Planing and Layout
Turbulences
Distances
Restrictions
Available land

21. Distances Rule of thumbs:
3-5 rotor diameter distance 90° to the main wind direction
5-10 rotor diameters distance in main wind direction
The larger the wind farm, the more distance should be kept
Orientation: Minimum 90 % park efficiency (=10 % wake losses)

22. Turbulence Wake turbulence
Source:
Wake turbulence

23. Turbine suitability Choosing the right turbine for the site
IEC Classification
Hub height, rotor diameter
Transport possibilities
Availability (supply)
Service possibilities
Restriction
Track record
Proven technology
Reputation of manufacturer
Site suitability
Assessment of IEC class and subclass
Turbulence calculation
Site suitability confirmation of manufacturer

24. Site Suitability Analysis
Qualified on-site wind measurement required
Assessment of IEC Classes:
Reference wind speed (Max 10min wind speed in 50yrs)
Average annual wind speed
Turbulence Intensity
Calculation of turbulence intensity including:
Ambient and representative turbulence intensity
Effective turbulence intensity
Wind class I II
III
Vref
50 m/s
42.5 m/s
37.5 m/s
Vave
10 m/s
8.5 m/s
7.5 m/s
Turbulence class at 15 m/s A
18.0 % B
15.7 % C
13.5 %

25. Site Suitability Analysis
IEC III are made to low wind region
Huge rotor diameter compared to small rated capacity
Examples:
Manufacturer
Turbine type
Rotor-diameter [m]
Hub height [m]
Rated Power [kW]
Vestas
V112
112
84, 94, 119, 140
3000
V126
126
119
Nordex
N117
117
91, 120, 141
2400
Gamesa
G114
114
93, 120, 140
2000
Goldwind
GW109
109 90
2500
GW106
106
80, 90

26. Site Suitability Analysis

27. Environmental restrictions
Shadow
Distance to housing areas
Noise
Wild Live
Endangered Species – Bird trails
Landscape
Distance to National Parks, Monuments, etc.
Country specific requirements

28. Wind park planning
Wind park planning, available land and exclusion areas merged

29. Wind park planning
Wind resource map

30. Wind park planning
Wind park planning, micro siting at optimal positions

31. Key requirements to a bankable wind study
Site visit
Quality control of wind data
Measure-Correlate-Predict (MCP)-Procedures (gap filling)
Long-term correlation with suitable long-term references
Vertical / Horizontal Flow Modelling Procedure
Gross energy yield
Loss estimation
Uncertainty estimation
Probability of Exceedance (PoE)

32. Relevant norms and guidelines
IEC Annex G
Mounting of instruments on meteorological mast
IEC Ed.3: Wind turbines – Part 1: Design Requirements
Specifies essential design requirements to ensure the engineering integrity of wind turbines
Measnet: Evaluation of site specific wind conditions
Site inspection
Relevant meteorological parameters
Representativeness of wind measurements
Measurement documentation
Data evaluation and extrapolation
Derived results
Reporting
Technical Guidelines for wind turbines Part 6: Determination of Wind Potential and Energy Yields
German guideline published by non-profit organization: Foerdergesellschaft Windenergie e.V. (FGW)

33. Thank you for your kind attention
Q & A
Thank you for your kind attention
Contact: Anil Bindal
Tel: +49 (0)
Website:

34. Q & A
Appendix

35. On-site Wind measurement
Sensors
well-designed
State of the art: „ First Class“ cup anemometers, with high measurement accuracy and relatively high insensitivity regarding turbulence and low power consumption
Wind speed sensors individually calibrated in wind tunnel
Wind direction measured with wind vanes
Redundant wind speed (on same height above ground) and direction sensors (different heights)
Additional sensors for temperature, humidity, pressure and evtl. solar radiation
poor-designed
Source: IEA Expert group study: 11. Wind speed measurement and use of cup anemometry

36. On-site Wind measurement
General recommendations for met mast siting
Representative position within wind farm
Covering of as much turbine positions as possible within representative radius
Position free from obstacles within a radius of times obstacle height
Position with regular flow conditions
Not on or behind sharp ridges (recirculation zones)
Not in depressions
Preferably in flat area or on smooth shaped hills

37. On-site Wind measurement
Placing of met mast(s) on the Wind farm site
Questions to be answered:
How many met masts are necessary?
Which height of mast is necessary?
Where to put the met mast(s)?
Additional measurement of vertical profile necessary?

38. On-site Wind measurement
Number of met mast(s) on the wind farm site
Two terrain types can be distinguished!
Simple terrain (Desert)
Complex terrain (Italian Alps)
- Minor Relief
- Negligible influence of orography on wind speed
- Wind conditions only influenced by roughness
- Significant relief
- Slopes with steepness > 30%
- Wind conditions influenced by roughness and
orography

39. On-site Wind measurement
Representative radius of met masts
Terrain type
Minimum measurement height a. g.
Representative radius of mast (max. distance of any wind turbine to mast)
Simple Terrain: (Example Desert)
2/3 of hub height
10 km
Complex Terrain: (Example Italian Alps)
2/3 of hub height (mast on plateau), hub height if mast on ridge
2 km
Could be even less in very complex terrain
- Significant relief
- Slopes with steepness > 30%
- Wind conditions influenced by roughness and
orography
Source: MEASNET-Evaluation of site specific wind conditions, 2009

40. On-site Wind measurement
Flow disturbances of tubular and lattice tower

41. On-site Wind measurement
Example of State-of-the-Art Design: Top Sensors
Source: IEC standard
Alternative according to IEC : no single top sensor, two sensors at same
height mounted on booms.

42. Site Assessment
Example for State-of-the-art design: Lower sensors