COLD CLIMATE RESOURCE ASSESSMENT: LESSONS LEARNED PHILIPPE C. PONTBRIAND RES-Canada Technical Lead
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Transcript of COLD CLIMATE RESOURCE ASSESSMENT: LESSONS LEARNED PHILIPPE C. PONTBRIAND RES-Canada Technical Lead
COLD CLIMATE RESOURCE ASSESSMENT:LESSONS LEARNEDPHILIPPE C. PONTBRIANDRES-Canada Technical Lead
Collaborators:Eric Muszynski, Rory Curtis
2nd NOVEMBER 2010
Presentation Plan
• Introduction– Canadian climate– Impact of Cold Climate (CC) on project development
• Icing– Icing type– Icing prediction– RES experience
• Cold climate measurement system– Tower and instrumentation– Portable power system– Cost/Benefit analysis
• Cold climate and uncertainty
Introduction
• Lesson #1
• Challenges
– Very cold average temp– Extreme min. and max. temp– Average snow depth 0.5 to 2m – Icing over 6-7 months
C = Canada old
Mean Temperature (°C)
Impact of CC on Project development
Tower InstallationTime constraints
Wind measurementIcing on InstrumentsLoad on met towers
MaintenanceSite accessCold Temp.
Development RFP Financing
Requirements
Predicted Wind
Predicted Energy
$/KWh Price
Predicted Wind
Predicted Energy
Higher Risks
Equity vs Debt
Winter 1 Winter 2 Winter 3
Per
cent
dat
a ca
ptur
e (%
)
Icing and Wind Resource Assessment
Type of Icing• Precipitation Icing
– Freezing rain• Regional• Not very common • High impact
– Wet Snow • Not so common on site• Varying adhesion
• In cloud Icing– Rime ice
• Most common• Local• Strong adhesion
– Frost • Not very common
Worst enemies
Klock et al., 2001
Will there be icing at my site?• Ice Map
– Freezing rain• Public Maps : Env. Canada • Very General
– Rime ice + Freezing Rain• Few maps for Canada• Not much research
Cortinas et al. 2004
Comeau et al. 2008
• Public Ice Measurement Data• Almost none exists: Airports Env. Canada• Often far from site• Not always accurate
Goodrich (Rosemount) Ice Sensor
Altitude (m asl) 8
Altitude VS Icing in Canada
• 75 met towers operated by RES across Canada– Full winter of data(October to May)– Anemometer height from 50 – 80m
Above 550 meters AMSL:
Sensors affected > 10% of time
Hou
rs o
f ici
ng (O
ct-M
ay)
Mean hours of icing of unheated instrument vs Altitude
Cold Climate Measurement System
Cold climate measurement systems
Tubular 50-60m Lattice 80m
A2 A1
HE-V1HE-A1
A4
A5
A3
A6
V1
V2
- More expensive
+ Low maintenance cost+ Re-use value
- Longer to install
+ Data @ Hub Height
+ Lower initial cost
- High maintenance cost- Re-use value
- More likely to collapse- No data @ Hub Height ?
Vaisala WAA252NRG IceFree
Cold Climate Met Mast Life CycleAssumption 1: Applies only to sites prone to icing
Assumption 2 : 2 maintenances per year per mast
Assumption 3: For lattice: 1 tower out of 2 is refurbished.
Assumption 4: For tubular: 1 tower out of 4 fails over lifetime
Cumulative Running Cost
Cos
t Rat
io
Great Primary Mast
Met Masts Summary
• Good long term value
• Reduced shear uncertainty
• Potential for better data availability
80 m lattice
50 – 60 m tubular
• Good short term value
• Easier and faster to install Great Secondary Mast
Autonomous Power System
Small Wind Turbine RES Generators
1st generation
2nd generation
Wind Turbines 1 kW:
• Cheap: $10K• Max of 2 heated instruments• Not much flexibility • Eco-Friendly• Affected by trees• Tend to freeze
RES Generator:
• More: $35K• Many instruments• Flexible
• Close to 100% availability • Remote diagnostic tools • Easy to deploy
Heating system concept
RES Autonomous Power System Concept
Impact of CC on Project development
Tower InstallationTime constraints
Wind measurementIcing on InstrumentsLoad on met towers
MaintenanceSite accessCold Temp.
Development RFP Financing
Requirements
Predicted Wind
Predicted Energy
$/KWh Price
Predicted Wind
Predicted Energy
Higher Risks
Equity vs Debt
Winter 1 Winter 2 Winter 3
Per
cent
dat
a ca
ptur
e (%
)
Cold Climate and Uncertainty
Cold Climate and Uncertainty
•P50 is the amount of energy expected to be produced in an average year
• 50% chance lower. 50% chance higher than this value
•For many projects debt is sized on 1 year P99
• Annual energy production only expected to be as low as this (or lower) once every 100 years
• What is the effect of higher P99/P50 ratio?• In other words: What is the value of lower uncertainty?
• Example: 100MW project, $135/MWh, 35% Cf , P99(1 Year) / P50 = 70%
• Increase P50 energy by 1% (Increase Cf to 35.35%),
• Power price will reduce by ~ $1.35/MWh
• Keep P50 at 35% Cf and increase P99(1 Year) / P50 ratio by 1% to 71%
• Power price will reduce by more than one might think
• 1% P99/P50 change has same value as around 0.5% to 0.7% change on P50
• Just an example treating P50 and P99 in isolation. Project financing dependent
Conclusions
Conclusions:
•First of All …
• Never underestimate the challenges of Canada’s cold climate
•Icing
•Not much research available to help characterize a Canadian site
•Information about icing can be extracted from simple parameters like altitude
•Towers and Instrumentation
•Tower and instrument type need to be chosen carefully
• Heating the instruments with the proper power system is a must
•Cost of Uncertainty
• De-icing and maintenance of instruments are key to reducing uncertainty