Performance
Forensics
Identifying and Quantifying Sources
of Lost Energy
February 2016
2
OBJECTIVES
 Demonstrate the process for comparing
preconstruction estimates and actual
energy produced
 Identify common pitfalls of this process
 Identify common pitfalls with information
typically provided in operating reports
3
WHY DO I CARE???
 Is the wind farm performing properly?
 Justify and direct efforts for improving
performance
 Adjusting the budgets and financial
model
4
HOW IS MY PROJECT PERFORMING?
 Questions Asset Managers ask Operators:
 How did the facility perform compared to budgets?
 How do my losses compare to budgets?
 Was it a low wind year?
880
869.6
870
Yield (GWh/year)
860
850
-25.4
840
830
6.8
838.3
Shutdown
Losses
Realized
Production
(GWh/Year)
-12.6
820
810
800
Preconstruction Wind Resource
Potential
Budget
(GWh/Year)
Deficit
Surplus
Equipment
Performance
Losses
5
HOW IS MY PROJECT PERFORMING?
 Questions Operators ask:
 What losses are recoverable?
 How windy will it be in the future?
 What should our future expectations be?
880
869.6
870
Yield (GWh/year)
860
17.2
858.1
Updated
Resource
Potential
Future Energy
Expectations
(GWh/Year)
850
-25.4
840
830
6.8
7.0
838.3
-4.4
-12.6
820
810
800
Preconstruction Wind Resource
Potential
Budget
(GWh/Year)
Deficit
Surplus
Equipment
Performance
Losses
Shutdown
Losses
Realized
Production
(GWh/Year)
Recoverable
Shutdown
Losses
Recoverable
Equipment
Performance
Losses
6
CATEGORIZATION OF LOSSES
Quantified in units of MWh
IEC Production-Based Availability Categories: 61400-26-2
Full Performance
Generating
Partial Performance
Technical Standby
Operating
Non-Generating Out of Environmental
Specifications
NonOperating
Requested Shutdown
Out of Electrical Specification
Scheduled Maintenance
Planned Corrective Action
Forced Outage
Suspended
Force Majeure
Equipment Performance Losses
Shutdown Losses
Non-Technical (not covered under contract)
Availability
Technical
(covered under contract)
Availability
7
Quantified in (%)
Quantified in units of MWh
Standardized Preconstruction Loss Categories[1]
IEC Production-Based Availability Categories: 61400-26-2
Wake
Internal, External Wake
Full Performance
Turbine Performance
Power Curve, Wind Flow
Conditions
Partial Performance
Environmental
Degradation Due to Icing,
Equipment Degradation
Technical Standby
Availability
Turbine Other
Out of Environmental
Specifications
Environmental/Turbine
Performance
Generating
Operating
NonGenerating
NonOperating
Requested Shutdown
Out of Electrical Specification
Scheduled Maintenance
Planned Corrective Action
Forced Outage
Suspended
Force Majeure
Wind Resource Potential
Equipment Performance Losses
Shutdown Losses
Electrical Losses
Curtailment
Availability
Availability
Availability
Availabilty
Availability
Other
Shut down due to icing,
lightning, hail, High and
Low Temperature, High
Wind, Site Access
All Curtailment
Balance of Plant, Grid
Turbine (Other)
Turbine (Contractual)
Turbine (Contractual)
Turbine (Contractual)
Force Majeure
Electrical
Electrical Losses
[1] Jones, S., Standard Loss Definitions for Wind Resource/Energy
Assessments, AWEA, WINDPOWER 2008, Washington
Order of Operations
RECONCILIATION WITH PRECONSTRUCTION
ESTIMATES
8
RECONCILIATION WITH PRECONSTRUCTION
ESTIMATES
Order of Operations
Preconstruction
Assumptions
Gross Yields (GWh/year)
Wake
Internal, External Wake
Power Curve, Wind Flow
Turbine Performance
Conditions
Degradation Due to Icing,
Environmental
Equipment Degradation
Turbine Other
Shut down due to icing,
lightning, hail, High and Low
Non-Technical Availability Temperature, High Wind, Site
Access
All Curtailment
Balance of Plant, Grid
Scheduled Maintenance
Planned Corrective Action
Technical Availability
Forced Outage
Suspended
Other
Force Majeure
Electrical
Electrical Losses
Total Losses
Net Yields (GWh/year)
Wind Resource Potential
Equipment Performance Losses
Shutdown Losses
Electrical Losses
(%)
GWh/year
5.0%
1019.0
51.0
0.3%
2.9
1.3%
12.5
0.0%
0.0
1.6%
15.2
0.1%
0.6%
0.6%
0.9
5.6
5.6
3.5%
32.4
0.0%
2.6%
14.7%
-
0.0
23.2
149.4
875.0
=0.3% x (1019.0- 51.0)
[1] Jones, S., Standard Loss Definitions for Wind Resource/Energy
Assessments, AWEA, WINDPOWER 2008, Washington
9
SHUTDOWN LOSS CATEGORIES
880






869.6
870
Turbine Faults (Technical)
Maintenance (Technical)
BOP downtime
Manual Stops
Force Majeure
Weather Related Shutdown
858.1
Yield (GWh/year)
860
17.2
850
-25.4
840
830
6.8
7.0
838.3
-4.4
-12.6
820
810
800
Preconstruction Wind Resource
Potential
Budget
(GWh/Year)
Deficit
Surplus
Equipment
Performance
Losses
Shutdown
Losses
Realized
Production
(GWh/Year)
Recoverable
Shutdown
Losses
Recoverable
Equipment
Performance
Losses
Updated
Resource
Potential
Future Energy
Expectations
(GWh/Year)
10
Deficit
QUANTIFYING DOWNTIME LOSSES
 Isolate periods of downtime
 SCADA codes
 Outliers from learned power curve
 Multiple techniques available to
quantify energy[1]
 Nearest neighbouring turbine
 Deficit from learned power curve
[1] IEC 61400-26-2, Wind turbines- Part 26-2: Production-based availability for wind turbines
11
QUANTIFYING DOWNTIME LOSSES
Pitfalls Common to Operations
Reports:
 Nacelle wind speeds are not free
stream wind speeds
 Comparing nacelle anemometer
wind speeds to warranted power
curves typically underestimate
losses
 Technical availability is not
comprehensive
 Losses can occur without turbine
fault codes
 Time vs. production based losses
 Lack of proper instrumentation and
maintenance
 Properly maintained and monitored
nacelle anemometry
Nacelle Instrumentation
Tower Instrumentation
12
EQUIPMENT PERFORMANCE LOSS CATEGORIES
880





869.6
Power Curve (Measured vs Warranted)
Wind flow conditions
Degradation due to icing/environmental
Equipment degradation (drivetrain, blades)
Partial Performance (Maintenance or other)
870
Yield (GWh/year)
860
17.2
858.1
Updated
Resource
Potential
Future Energy
Expectations
(GWh/Year)
850
-25.4
840
830
6.8
7.0
838.3
-4.4
-12.6
820
810
800
Preconstruction Wind Resource
Potential
Budget
(GWh/Year)
Deficit
Surplus
Equipment
Performance
Losses
Shutdown
Losses
Realized
Production
(GWh/Year)
Recoverable
Shutdown
Losses
Recoverable
Equipment
Performance
Losses
13
QUANTIFYING PERFORMANCE LOSSES
 Irregular performance quantified similar
to shutdown losses
 Identify periods of underperformance
 Quantify lost energy
 Systematic losses must be quantified
via more in-depth analysis
 Power performance testing
 Step change/degradation analysis
14
WIND RESOURCE POTENTIAL
880






869.6
870
Preconstruction wind speed measurements
Long-term wind speed predictions
Vertical wind speed extrapolation
Wind flow modeling
Wake Losses
Operational Period vs Long-term (Variability)
858.1
Yield (GWh/year)
860
17.2
850
-25.4
840
830
6.8
7.0
838.3
-4.4
-12.6
820
810
800
Preconstruction Wind Resource
Potential
Budget
(GWh/Year)
Deficit
Surplus
Equipment
Performance
Losses
Shutdown
Losses
Realized
Production
(GWh/Year)
Recoverable
Shutdown
Losses
Recoverable
Equipment
Performance
Losses
Updated
Resource
Potential
Future Energy
Expectations
(GWh/Year)
15
QUANTIFYING RESOURCE POTENTIAL
Pitfalls:
 Nacelle or permanent met tower data
is not necessarily equivalent to budget
wind speeds
 A post-construction long-term
prediction of wind resource
potential should be calculated by
comparing to a long-term reference
site
 The production sensitivity of the
power curve must be considered
 For every 1% change in wind
speed, the turbine experiences
1.3% to 2.0% change in
production, depending on the
technology
16
QUANTIFYING RESOURCE POTENTIAL
Suggested methodology
 Generate a long-term prediction of
onsite measurements (nacelle or
permeant tower)
 Quantify power curve sensitivity from
this long-term prediction
 Compare monthly measurements to
long-term prediction with sensitivity
applied
 Monitor and maintain nacelle or
permanent tower instruments
17
WHICH LOSSES ARE RECOVERABLE?
880






869.6
870
Turbine Faults (Technical) to worsen
Maintenance (Technical)
BOP downtime to worsen
Manual Stops
Force Majeure
Weather Related Shutdown to improve
858.1
Yield (GWh/year)
860
17.2
850
-25.4
840
830
6.8
7.0
838.3
-4.4
-12.6
820
810
800
Preconstruction Wind Resource
Potential
Budget
(GWh/Year)
Deficit
Surplus
Equipment
Performance
Losses
Shutdown
Losses
Realized
Production
(GWh/Year)
Recoverable
Shutdown
Losses
Recoverable
Equipment
Performance
Losses
Updated
Resource
Potential
Future Energy
Expectations
(GWh/Year)
18
WHICH LOSSES ARE RECOVERABLE?
880





869.6
Power Curve to improve with retrofits
Wind flow conditions
Icing loss to improve due to variability
Equipment degradation
Partial Performance (Maintenance)
870
Yield (GWh/year)
860
17.2
858.1
Updated
Resource
Potential
Future Energy
Expectations
(GWh/Year)
850
-25.4
840
830
6.8
7.0
838.3
-4.4
-12.6
820
810
800
Preconstruction Wind Resource
Potential
Budget
(GWh/Year)
Deficit
Surplus
Equipment
Performance
Losses
Shutdown
Losses
Realized
Production
(GWh/Year)
Recoverable
Shutdown
Losses
Recoverable
Equipment
Performance
Losses
19
WHICH LOSSES ARE RECOVERABLE?
880





869.6
870
Preconstruction wind speed measurements
Long-term wind speed predictions
Vertical wind speed extrapolation
Wind flow modeling, wake losses
Operational Period vs Long-term to improve
due to variability
17.2
Yield (GWh/year)
860
858.1
850
-25.4
840
830
6.8
7.0
838.3
-4.4
-12.6
820
810
800
Preconstruction Wind Resource
Potential
Budget
(GWh/Year)
Deficit
Surplus
Equipment
Performance
Losses
Shutdown
Losses
Realized
Production
(GWh/Year)
Recoverable
Shutdown
Losses
Recoverable
Equipment
Performance
Losses
Updated
Resource
Potential
Future Energy
Expectations
(GWh/Year)
20
CONCLUSIONS
 Standard loss categories can be
mapped to preconstruction loss
categories
 The order of operation of losses is
important
 Maintain good met data
 Question the input metrics you are
getting for your analysis (wind
resource potential, availability)
 Do your math in MWh not % when
possible
21
REFERENCE CASE STUDY
Preconstruction
Assumptions
(%)
Gross Yields (GWh/year)
Preconstruction Bias
Wind Speeds
Wind Variability
Wake
Internal, External Wake
Power Curve, Wind Flow
Turbine Performance
Conditions
Degradation Due to Icing,
Environmental
Equipment Degradation
Turbine Other
Shut down due to icing,
lightning, hail, High and Low
Non-Technical Availability Temperature, High Wind, Site
Access
All Curtailment
Balance of Plant, Grid
Scheduled Maintenance
Planned Corrective Action
Technical Availability
Forced Outage
Suspended
Other
Force Majeure
Electrical
Electrical Losses
5.0%
0.3%
Anticipated
Operational Period PreconstructionImprovement
Realized Losses
GWh/year GWh/year
%
(GWh/year)
GWh/year
(%)
1019.0
1019.0
6.5
0.5%
20.2
2.0% -25.4
-2.9%
17.2
2.0%
5.0%
51.0
49.6
2.9
21.6
2.3%
4.4
-12.6
-1.5%
0.8%
1.3%
12.5
6.5
0.7%
2.6
0.0%
0.0
0.0
0.0%
-
1.6%
15.2
31.2
3.4%
4.1
0.1%
0.6%
0.6%
0.9
5.6
5.6
0.9
1.6
5.1
0.1%
0.2%
0.6%
3.5%
32.4
14.2
1.6%
0.0%
2.6%
0.0
23.2
0.0
23.2
Total Losses
14.7%
149.4
180.7
Net Yields (GWh/year)
-
869.6
838.3
0.0%
2.7%
17.7
%
-
Wind Resource Potential
Equipment Performance Losses
Shutdown Losses
Electrical Losses
6.8
0.8%
-
-
-2.0
-6.5
-
31.3
3.6%
19.8
2.4%
-
-
858.1
-
-0.5%
-
22
Thank You
Errol Halberg
[email protected]