COLD CLIMATE RESOURCE ASSESSMENT: LESSONS LEARNED PHILIPPE C. PONTBRIAND RES-Canada Technical Lead Collaborators: Eric Muszynski, Rory Curtis 2 nd 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 = C anadaold Mean Temperature (°C)

Impact of CC on Project development Tower Installation Time constraints Wind measurement Icing on Instruments Load on met towers Maintenance Site access Cold 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 Percent data capture (%)

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 Comeau et al 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 Hours of icing (Oct-May) Mean hours of icing of unheated instrument vs Altitude

Cold Climate Measurement System

Cold climate measurement systems Tubular 50-60mLattice 80m A2 A1 HE-V1 HE-A1 A4 A5 A3 A6 V1 V2 - More expensive + Low maintenance cost + Re-use value - Longer to install + Hub Height + Lower initial cost - High maintenance cost - Re-use value - More likely to collapse - No Hub Height ? Vaisala WAA252 NRG IceFree

Cold Climate Met Mast Life Cycle Assumption 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 Cost Ratio

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 TurbineRES Generators 1 st generation 2 nd 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 Installation Time constraints Wind measurement Icing on Instruments Load on met towers Maintenance Site access Cold 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 Percent data capture (%)

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