Monitoring Gear Boxes with PeakVue - Niagara Frontier Chapter Home
Wind Industry and Gear Boxes
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Transcript of Wind Industry and Gear Boxes
Wind Industry and Gear Boxes
Uwe Roeper
Hamilton Dinner
November 17, 2009
ORTECH Power
• 40 staff • Engineers & Consultants
– Technical Due Diligence / IE– Wind resources assessment– Plans & Permits– Financial Analysis– Operations Support
Wind Energy in Canada (2008)
Source: CanWEA
• 526 MW added in 2008 = 2nd highest year•Capacity end 2008: 2,372 MW = Electricity for over 600,000 homes = 1% of Canada’s total demand
Wind Growth in Canada (MW)
Source: CanWEA
Wind in Canada (2009 & beyond)
• Current installed capacity (May 2009) – 2,550 MW• Project a total of 650 MW to be installed this year (2nd best
year ever), pushing Canada over the 3,000 MW mark• An additional 5,000 MW of projects are either contracted
or under construction• Provincial government targets, if fully achieved, would
result in 12,000 MW of installed capacity in Canada by 2015
Source: CanWEA
Gear Boxes – The Weak Link
• What is the role of gear boxes in wind turbines?
• Why are they getting so much attention from the wind community?
• How does this relate back to lubrication engineering?
Source: CanWEA
Design Issues• Gear boxes need to light weight but handle
large stresses:– Typical size 2500 HP / 90 m Rotor– Variable speeds & loads– Torsion from uneven wind loads
• Approaching practical design limits of available materials.
• Constant push for cheaper cost per unit energy.
How are things working out?• Underperformance has been a key topic at AWEA and
CanWEA over past 2 years.– Typical underperformance of 10% based on major investigations
of existing farms:• 59 facilities / 243 years = 11% below P50• 41 facilities / 113 years = 90% of P50• Range 80% to 105%
• Financial significance on affected projects is high.– Senior Lenders: reduced DSCR, increased risk– Equity: very large reduction in cash flow
GH (AWEA 2008) 70 WF yrs
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WF
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GH actual P50 Log?
Cashflow & Underperformance
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Actual vs P50 (at 70% debt)
$ M
M Equity
Debt
IRR=11% IRR=6%
IRR= -(1)%
MW=100, P=$89/MWh, L=70%, I=7%, CF=34.1%, CapEx=2.4,OpEx=16%, Term=20, TV=0
Potential Causes• Over prediction of:
– Wind– Efficiency– Mechanical Availability
• (including due to gear boxes)
1. Understand Wind related factorsAnnual Variations in Wind Speed and Energy Production
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Linear (Normalized Wind Energy)
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10-min averages
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correctcorrectrotor planepositive negative
wind speed vector
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top view
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2. Unterstand efficiency factors
3. Understand mechanical factors
Drive Train
Structurals
Generator
Gearbox
Rotor Hub
Mech. Brakes
Rotor Blades
Yaw/Pitch Sys.
Hydraulics
Sensors
Electronics
Electrical
Down time per failure [days]Annual failure frequency [-]1 0,75 0,5 0,25 0 2 4 6
Example
Pro-Active ReactiveCostsRepair & Refurbishment 95,000$ 225,000$ Crane Costs 76,932$ 100,000$ Lost Revenue - $1,008/Day 4 4,032$ 30 30,240$ Condition Monitoring Costs 5,000$ -$ Spare Component Carrying Costs 19,072$ -$
Total 200,036$ 355,240$
Gearbox Repair & Refurbishment Costs
Understand Parts Life Cycles
• While unscheduled minor maintenance is expected to remain fairly constant, major repair will occur in intervals and increase in cost with age.
• Outages will generally increase along with major repairs.
Annual Repair & Maintenance Expenditure (illustration)
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Manage Life Cycle CostLife Cycle Cost: Pro-active vs Reactive Maintenance Approach)
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• 20-year life cycle costs for repair and outages can vary from under $0.4 mill/WTG (pro-active mtc.) to over $1 mill/WTG (reactive mtc.). High mechanical loads (turbulence, ice, defects) can further increase cost (up to $2 mill/WTG in extreme cases).
Prevention Strategies?
• Early detection• Preventative maintenance
For gear boxes early detection is key
Most wind farms have an inadequate preventative maintenance program,parts inventory and supply chain.
Use Condition Monitoring
AFTER
BEFORE
Utilize Inspection Tools
Other Prevention Strategies?
• Improve design.
• Manage mechanical loads.
• Improve … lubrication?
Wind & Gear Boxes
• Rapid growth in wind is creating engineering challenges for mechanical design and life cycle expectations.
• Gear box failures are central to the life cycle economics of wind farms.
• More can be done to improve life expectancy on this key component.