the impacts of uprating and derating on wind turbine reliability
DESCRIPTION
How can you know the impact of uprating and derating wind turbines? Today, most OEMs offer uprating packages (GE PowerUp, Vestas PowerPlus, etc.) that allow for existing wind turbines to realize higher annual power production. The impact on reliability through derating or uprating is unknown through industry standard techniques. This has led to well under 20 year life of current wind turbine gearboxes.TRANSCRIPT
The Impacts of Uprating and Derating on
Turbine Reliability
Why Are We Here
What is re-rating and how
can I know my real ROI?
Need to know, what is my
baseline reliability and what is the
impact of
re-rating?
The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
Rating Options – Derate
Reduce loads to extend life
1) Partial Derate
2) Wind Speed Based
3) Turbulence Based
0
0.5
1
1.5
Partial Derate
Potential Power Actual Limit
0
0.2
0.4
0.6
0.8
1
1.2
Wind/Turbulence Derate
Potential Power Actual Limit Speed/Turb Max
Reduce loads to extend life.The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
Rating Options – Uprate
Increase AEP, Increase Profit
1) Controls: Reduce Loads = More Power• Take advantage of lower loads
2) Increased Rating• E.G. 2.0MW to a 2.1MW
3) Vortex Generators: 1 – 2% annually
4) Larger Blades• Better controls and design to allow for longer blades
5) Combination of Above and More
The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
Current Reliability Assumptions
• Myth: Drivetrain components are reliable
• Myth: Standards certify 20 year reliability
• Myth: Design life is 20 yrs, expect 20 yrs
The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
• Results: Budgeted flat/levelized fixed
maintenance cost after warranty period
• Minimum = inflation
• Maximum = rare, one gearbox replacement
per WTG
Current Reliability Assumptions – Impact
on Budgeting
The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
Case Study (Budgeted) -Current Assumptions
Budgeted
AEP --
Fail Rate --
NCF 38%
20 Yr IRR 14.36%
Annual DSCR 1.62
NPV (Life) $59,351k
The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
Case Study (Budgeted) -Current Assumptions w/Uprating
Budgeted 5%AEP
AEP -- ↑5%
Fail Rate -- ↑50%
NCF 38% 39.9%
20 Yr IRR 14.36% 15.08%
Annual DSCR 1.62 1.67
NPV (Life) $59,351k $62,603
The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
How Can I Know My Baseline Reliability?
Sentient’s DigitalClone Live
model predicts:
• Real reliability of wind
turbines (baseline)
• Impact of rating options on
reliability
The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
How We ModelDigitalClone® - Nucleation & Propagation
Too Late
The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
Manage the Fleet Through Financial
Optimization
Year: 2014
Today
Year: 2011
3.7%
As-Is Failure Profile
Optimized Condition
Reduction in % of
Failures
Sentient’s services predict
the true baseline and impact
of maintenance and
operational changes.
Life extension or increased
AEP by quantifying the
impact of:
- Wind conditions
- Lubrication change
- Turbine re-rating
- Uptower replacements
- Remanufacturing
- Automated spare parts
management
The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
Case Studies Using DigitalClone
• Four Scenarios
1. Baseline
2. Derate
3. Uprate – +2% AEP
• Vortex Gen
4. Uprate – +5% AEP• ↑10% Rating
• Notes:
• Data is normalized for
average site and average
wind turbine
The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
Case Study (Baseline) -
Real Performance w/Sentient
Budgeted Real
AEP -- --
Fail Rate -- ↑500%
NCF 38% 38%
20 Yr IRR 14.36% 12.08%
Annual DSCR 1.62 1.45
NPV (Life) $59,351k $247k
Performance is marginal
The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
Case Study (Baseline) -
Underperforming
Real AEP5%
AEP -- ↓5%
Fail Rate -- --
NCF 38% 36.1%
20 Yr IRR 12.08% 11.79%
Annual DSCR 1.45 1.45
NPV (Life) $247k ($653k)
Sensitive to underperformance
The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
Case Study (Derating) -Failure Rate ↓25% / AEP ↓ 13%
Real AEP5%
AEP -- ↓13%
Fail Rate -- ↓25%
NCF 36.1%
20 Yr IRR 11.79% 8.88%
Annual DSCR 1.45 1.31
NPV (Life) ($653k) ($8,782k)
Reducing failure rates through derating
not an option
The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
Case Study (Uprating) -Failure Rate ↑4% / AEP ↑2%
Real AEP2%
AEP -- ↑2%
Fail Rate -- --
NCF 36.1% 38.8%
20 Yr IRR 11.79% 12.14%
Annual DSCR 1.45 1.47
NPV (Life) ($653k) $436k
A modest 2% increase in AEP with right
technology fixes site performance
The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
Case Study (Uprating) -Failure Rate ↑40% / AEP ↑5%
Real AEP5%
AEP -- ↑5%
Fail Rate -- ↑40%
NCF 36.1% 39.9%
20 Yr IRR 11.79% 11.80%
Annual DSCR 1.45 1.44
NPV (Life) ($653k) ($628k)
Overrating can cause little to no benefit
The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
Key Dependencies
• Key variables
• Site conditions
• Turbine supplier
• Component supplier
• Rating options selected
• Rating option supplier
• Etc.
All play key roles in real site
performance
The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
Automate With DigitalClone Live
The Impacts of Uprating and Derating on Turbine Reliability
October 23, 2014
The Impacts of Uprating and Derating on
Turbine Reliability