Overcoming IcingEffects on Wind

Turbines

John Maissan, P. John Maissan, P. EngEng.,.,DirectorDirector, , TechnicalTechnical ServicesServicesYukon Energy Yukon Energy CorportationCorportation

Rime and Glaze Icing• In the Whitehorse area, rime icing typically

occurs at higher altitudes

• Rime icing can also be present in lower lying areas further north than Whitehorse, particularly near sources of humidity

• Glaze icing can occur throughout most of North America, but is most prevalent along Canada’s east and west coastal regions

Higher Altitude Operation

Source: Finnish Meteorological Institute, Wind Energy Production in Cold Climate

• Higher energy winds tend to be found on ridges, hilltops and mountains

• These locations lead to cloud and rime ice formation

Measuring Duration and Severity of Icing

• Reliable detectors for rime and glaze icing needed

• Limited supply on market at present• Models on market do not seem to cope well

with severe rime icing• Two heated anemometer approach is

reasonably reliable

Wind Speed & Icing Event Monitoring – Haeckel Hill

Bonus Heated Bearing Anemometer (30 m) (replaced in first year)

NRG Heated Anemometer & Wind Vane (30 m). Ice detector at ground level.

Bonus 150 kW Performance

Icing Periods

Bonus Performance Under Icing

• Wind data multiplied by actual ice-free power curve to determine maximum possible energy yield per month

• This ice-free maximum is compared with actual performance data

• The performance data are then compared to icing data from the monitoring station

• All three are independent data sets

Manufacturer’s vs. Actual Power Curves

Bonus 150 Mark III Power Curve

y = -0.2817x3 + 7.9124x2 - 54.266x + 113.27

y = -0.3294x2 + 11.501x + 34.423

y = 0.3118x2 - 14.786x + 291.36

y = -0.2771x3 + 7.1491x2 - 40.098x + 66.161

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

160.0

0 5 10 15 20 25

Wind Speed (m/s)

Pow

er O

utpu

t (kW

)

Manufacturer's Curve

YEC Data Power Curve (No Ice)

Bonus 150 kW Actual vs. Theoretical Performance July 2002

0

5

10

15

20

25

30

35

40

1-Jul 6-Jul 11-Jul 16-Jul 21-Jul 26-Jul 31-Jul

Date

Pow

er P

rodu

ctio

n (k

Wh)

-160

-110

-60

-10

40

Icin

g In

tens

ity

Actual Power ProducedTheoretical Power AvailableNRG Icing

Actual Power ProducedIce-free Power AvailableGoodrich (Rosemount) Icing

Bonus 150 kW Actual v. Ice-free Performance July 2002

Actual Power ProducedIce-Free Power AvailableGoodrich (Rosemount) Icing

No icing Icin

g In

tens

ity

-40

-20

0

Bonus 150 kW Actual vs. Theoretical Performance July 2002

0

5

10

15

20

25

30

35

40

7/13/02 0:00 7/13/02 12:00 7/14/02 0:00 7/14/02 12:00 7/15/02 0:00 7/15/02 12:00 7/16/02 0:00

Date

Pow

er P

rodu

ctio

n (k

Wh)

-160

-110

-60

-10

40

Icin

g In

tens

ity

Actual Power ProducedTheoretical Power AvailableNRG Icing

Bonus 150 kW Actual v. Ice-free Performance July 2002

Actual Power ProducedIce-Free Power AvailableGoodrich (Rosemount) Icing

Icin

g In

tens

ity

-40

-20

0No icing

Bonus 150 kW Actual vs. Theoretical Performance January 2001

0

5

10

15

20

25

30

35

40

1-Jan 6-Jan 11-Jan 16-Jan 21-Jan 26-Jan 31-Jan

Date

Pow

er P

rodu

ctio

n (k

Wh)

-160

-110

-60

-10

40

Icin

g In

tens

ity

Actual Power ProducedTheoretical Power AvailableNRG Icing

Underproduction due to Ice

Icin

g In

tens

ity

-40

-20

0

Bonus 150 kW Actual v. Ice-free Performance January 2001

Actual Power ProducedIce-Free Power AvailableGoodrich (Rosemount) Icing

Bonus 150 kW Actual vs. Theoretical Performance January 2001

0

5

10

15

20

25

30

35

40

1/1/01 0:00 1/2/01 0:00 1/3/01 0:00 1/4/01 0:00 1/5/01 0:00 1/6/01 0:00 1/7/01 0:00

Date

Pow

er P

rodu

ctio

n (k

Wh)

-160

-110

-60

-10

40

Icin

g In

tens

ity

Actual Power ProducedTheoretical Power AvailableNRG Icing

Note return to normal power – assistance from heaters and black blades

Bonus 150 kW Actual v. Ice-free Performance January 2001

Actual Power ProducedIce-Free Power AvailableGoodrich (Rosemount) Icing

Icin

g In

tens

ity

-40

-20

0

Power loss caused by icing

Achievements

• Heated wind instruments and ultrasonics now quite good

• Low temperature synthetic lubricants and fluids

• After-market blade heating systems and blade coatings

• Reductions in energy losses

Challenges Remaining

• Ice detectors for severe conditions• Off-the-shelf blade heating systems• Further reductions in energy losses• Adaptations of turbine control algorithms

Manufacturers Working on Cold/ Icing Environment Equipment

Large Machines• Vestas

• Bonus

• NEG Micon

• Enercon

• Lagerwey

Small Machines• Atlantic Orient Corp

• Vergnet

• Northern Power Systems

• Bergey

(no blade heating yet available)

Overcoming IcingEffects on Wind

Turbines

John Maissan, P. John Maissan, P. EngEng.,.,DirectorDirector, , TechnicalTechnical ServicesServicesYukon Energy Yukon Energy CorportationCorportation