Factors and considerations for achieving optimal wind farm performance in Thailand

Vladimir Krumov, 3rd June 2015,Renewable Energy Asia 2015, Bangkok, Thailand

Mott MacDonald Global Wind Capability

• A top global firm in power sector consultancy with pioneering role in the wind sector for over a decade

• Clients include Project Developers (Owner’s Engineer and Technical Advisory); International Lenders (Lender’s Engineer); Utilities; OEMs; Governments and regulatory bodies; Private equity groups (Acquisition Due Diligence)

• Supported the first commercial wind farms in a number of countries e.g. Thailand, Mongolia, various island states

• Regional offices in Bangkok, Singapore, Manila, Ho Chi Minh, Jakarta, Kuala Lumpur and Tokyo with strong local capabilities

• Global wind power track record exceeds 25 GW

Wind Project Experience in Southeast Asia

We have supported approximately 50% of the operational wind capacity in SE Asia

• West Huaybong 2&3, 207 MW, Lender’s Engineer, Thailand

• WED wind farm, 60 MW, Lender’s Engineer, Thailand

• Sub Yai wind farm, 90 MW, Owner’s Technical Advisor, Thailand

• Theppana wind farm, 7.5 MW, Owner’s Engineer, Thailand

• Koh Tao wind farm, 5 MW, Due Diligence Review, Thailand

• Confidential 125 MW wind Farm, Lenders Engineer, Thailand

• Confidential 60 MW wind farm, Chaiyaphum, Lender’s Engineer, Thailand

• Confidential 120 MW wind portfolio, Korat, Energy Yield Analysis, Thailand

• Nabas, 36 MW, Lender’s Engineer, Philippines

• San Lorenzo, 54 MW, Lender’s Engineer, Philippines

Factors influencing wind farm power performance

1. Wind Resource: Pre‐operational Energy Yield Assessment, Uncertainties and Variability

2. The WTG technology selection: Considerations for larger rotor diameters and higher hub heights. Power Curve operational envelopes and sensitivity.

3. Quality of construction and operation4. Conclusions

Wind Resource AssessmentWind Resource in Thailand

Source: Vortex

• Low to Medium Wind Speed

• Strong Seasonal and Diurnal Patterns:

• Wind Speed• Direction• Vertical wind speed profile• Turbulence Intensity• Atmospheric stability

Source: MERRA Reanalysis Data

Wind Resource AssessmentSeasonal Patterns

Wind Resource AssessmentConsiderations for low wind resource sites

Wind Resource AssessmentConsiderations for low wind resource sites

Wind Resource AssessmentConsiderations for low wind resource sites

± 1%± 2‐3%

Wind Resource AssessmentUncertainty Analysis

Uncertainty in Energy Production

10%

P50 100.0

P75 93.3

P90 87.2

P99 76.7

P50P75P90P99

Wind Resource AssessmentUncertainty Analysis

Uncertainty in Energy Production

10% 15% 20%

P50 100.0 100.0 100.0

P75 93.3 89.9 86.5

P90 87.2 80.8 74.4

P99 76.7 65.1 53.5

Wind Resource AssessmentInter-annual Variability

Data Source: MERRA Reanalysis Data

Wind Resource AssessmentLayout Optimisation

WTG Technology Selection

The selection of WTG selection is based on economical analysis and considering large number of factors including:

– Expected Energy Production– Commercial considerations: Capex, lead times, Opex– Technology’s track record and reliability– Contractual terms and warranties– O&M Agreements

Technology SelectionMaximising the Energy Yield

Source: Asavaroengchai and Krumov, 2014

• Larger Rotor Diameter:– Direct Increase of the rotor area results in 

more energy capture– Often comes with increased nominal power– The WTG specific power is an important 

parameter to observe

• Larger Hub Heights:– Commonly Extrapolation of mast 

measurements is used to predict wind speeds at larger height

– Careful analysis is required and extrapolation assumptions are often inaccurate for large heights

120m

Rotor Diameter

Hub

Hei

ght

80m

90m

100m

110m

80m 90m 100m 110m 120m

?

Source: Leosphere

Technology SelectionLarge hub height considerations

Technology SelectionLarge hub height considerations

Source: Mott MacDonald

Technology SelectionLarge hub height considerations

Source: Mott MacDonald

Technology SelectionPower Curve Performance

The Power output (Power Curve) of a wind turbine is dependent on:• Wind Speed• Air Density• Turbulence Intensity• Vertical Wind Sheer• Wind Veer• Inflow Angle

Source: EWEA’s Power Curve Working Group, www.pcwg.org

Technology SelectionPower Curve Performance

Source: Clifton and Wagner, 2014

Quality Assurance / Quality Checking

• Detailed technical due diligence review• Quality control management plan• Strong on site technical management during the construction phase 

• Robust testing and acceptance procedures• Operation and Maintenance arrangements• Operational power performance testing

Conclusions

• The low to moderate wind resource results in higher sensitivity to  uncertainties in the wind resource assessment

• Technology selection can make a difference. Power Curves should be sourced to cover all site specific conditions.

• Wind resource variability should always be considered and project cash‐flow should allow for “low” periods.

• The lack of contractors with long track record in wind energy projects raises the need for a strong technical management during the construction phase.

www.mottmac.com

Vladimir KrumovT +66 2643 8648 ext 223F +66 2643 8638/39E Vladimir.Krumov@mottmac.comW www.mottmac.com

19th Floor Chamnan Phenjati Building65/159 and 65/162 Rama 9 RoadHuay KwangBangkok 10310Thailand

Thank You!