The document discusses ENERCON's de-icing system for wind turbines. It provides details on the system's simplicity, safety features, low costs, and efficiency. Testing showed the system increased annual energy production by 10-15% on severe icing sites and 25% on some sites by minimizing losses from icing. ENERCON is further developing the system for its larger turbines like the E-126.

1. Further development of ENERCON‘s
de-icing system
Winter Wind, Skellefteå, 2012-02-07
Christoffer Jonsson
Site Assessment
(+46) 766 31 09 83
christoffer.jonsson@enercon.de
Filename: © Copyright ENERCON GmbH. All rights reserved.

2. Griessee: 1x E-70, 2465 m.a.s.l. – Europe‘s highest turbine
Photo: Swisswinds/ SIG
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3. Risks with icing on wind turbines
• Unbalance of rotor blades lead to oscillations causing higher loads and probably shut down.
• Ice pieces can fall down in a reasonable radius around the WEC.
• Degradation of aerodynamic efficiency resulting in decreased yield.
• Total stop of yield production due to ice detection.
• Operating turbines in cold climate is not an easy task!
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4. Simplicity
• The ENERCON de-icing system is based on a simple yet powerful idea (hot air inside the
blades).
• All parts can be changed within hours from failure by a technician.
• The technic is well proven for years. Third party validation available from Deutsche
WindGuard.
• All new models will have this feature as
an option.
• It works great!
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5. Safety
• ENERCON’s de-icing system is not affected by lightning strikes.
• No crane is needed to repair or perform maintenance work on the system.
• Air flow is limited to a specific area of the blade but will heat the whole volume it travels in.
• No enhanced risk for electrical malfunction in or outside of the blade.
• The amount of possible problems is very low!
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6. Low Costs
• ENERCON’s de-icing system can be repaid in just a couple of months (depending on the
site).
• Spare parts are cheap and can be installed, changed, up-dated and repaired with very small
effort.
• Costs for maintaining the de-icing system are very low.
• It’s a cheap way of increasing the availability!
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7. Efficient
• ENERCON’s first ice detection and de-icing system was installed in 2004.
• During 2009 – 2010 ENERCON added de-icing during operation of the turbine. This was a huge
improvement.
• According to the validation performed by Deutsche WindGuard our customers can estimate to
minimize the icing losses and gain 10 – 15 % in annual energy production due to the efficient
de-icing system during operations.
• On severe icing sites the gain from minimized icing losses can even
add up to 25% of additional energy yield.
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8. Test of rotor blade de-icing system performance
The efficiency of the rotor blade de-icing system has been tested for 5 months in winter 2009/2010
in locations at
a) Dragaliden in Sweden and
b) Krystofovy-Hamry in Czech Republic.
On both locations 2 WECs E-82 2 MW have been compared. Both WECs are located next to each
other.
On one WEC the rotor blade heating was activated while it was deactivated on the other WEC.
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9. Energy yield surplus due to Rotor blade de-icing Dragaliden
energy meter readings
Difference in yield per month between heated and unheated WEC E-82
2MW at location in Dragaliden (SE)
WEC 02 heating on WEC 01 heating off Yield difference
800.000
676.087
700.000
Total yield surplus:
579.905
569.974
600.000 870.000 kWh
490.729
477.533
500.000
energy yield [kWh]
397.636
353.515
324.655
322.572
400.000
279.210
279.061
300.000
211.519
153.767
200.000
72.981
100.000
9.931
0
Nov 09 Dez 09 Jan 10 Feb 10 Mrz 10
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10. Energy yield surplus due to Rotor blade de-icing in
Krystofovy-Hamry (CZ), energy meter readings
Difference in yield per month between heated and unheated WEC E-82
2MW at location in Czech Republic
WEC 10 heating on WEC 11 heating off Yield difference
700.000
624.271
Total yield surplus:
600.000
500.839
650.000 kWh
485.738
430.993
500.000
416.693
energy yield [kWh]
335.896
400.000 284.686
280.959
265.914
249.403
300.000
138.533
132.007
200.000
86.493
69.846
100.000
15.045
0
Nov 09 Dez 09 Jan 10 Feb 10 Mrz 10
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11. Results of rotor blade de-icing test period in winter 2009/2010
Krystofovy- Dragaliden
Location unit Hamry (CZ) (SE)
Amount of test month in winter month 5 5
Energy meter difference between WEC
with and without blade de-icing kWh 870.000 650.000
Average monthly energy surplus in winter
month with icing kWh 174.000 130.000
Percentage of energy surplus in relation to
WEC without de-icing system % 48 54
The energy yield surplus due to the rotor blade de-icing system strongly depends on
meteorological conditions like icing and wind speed on site.
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12. Future development of ENERCON’s de-icing systems
• ENERCON has developed ice detection solutions and de-icing systems for years.
• We see a growing interest for markets in cold climate since the world wide economic difficulties
in 2008.
• ENERCON is well prepared and we have validated proven technology to support our customers
needs.
• The next step will be to include this de-icing system to our newer and
bigger turbines…
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13. E-101 – Fan and radiator system
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14. De-icing system for the ENERCON E-126 7,5 MW
•The new de-icing system for the E126 is under development.
•The de-icing system is divided in two different systems. A new inner blade concept and the
approved concept for the outer blade.
Pipe Air heating element
Leading edge with hot air
Electrical heating pads
Ventilator
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15. De-icing system E-126, thermography picture
• Infrared photo with a first result of heating tests of the inner blade while the rotor is
rotating.
• Heating pads inside the steel blade heating up the outer surface and hot air heating up
the outer blade.
• Please notice that the mass of the inner blade ~ 60t !
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16. E-126, Inner blade - pipe
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17. E-126, Inner blade - full system
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18. De-icing system for the ENERCON E-126 7,5 MW
Pipe Air heating element
Leading edge with hot air
Electrical heating pads
Ventilator
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19. Main advantages with ENERCON rotor blade heating is …
• All systems are safe against lightening
• There are only two additional approved components
• There is no need to use specially designed blades
• Inexpensive
• Easy to handle for maintenance (all components are exchangeable)
• High efficiency to reduce energy yield loss due to icing
• System can work while rotor is rotating => leads to minimize the power consumption from the
grid
• It is simple, safe and works just great!
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20. Thank you for your attention!
Simple
Safe
Low cost
Efficient
Winter Wind, Skellefteå, 2012-02-07
Christoffer Jonsson
Site Assessment
(+46) 766 31 09 83
christoffer.jonsson@enercon.de
Filename: © Copyright ENERCON GmbH. All rights reserved.