Wind Turbines I

PETD Wind Blade Deicing Technology Full power production in the most severe icing conditions. Allows for wind farms in high wind locations heretofore disqualified due to icing.

● Instant de-icing & anti-Icing● Low power requirements ● Lightning strike protection ● Flexible control electronics● Patented worldwide

SPECIAL NOTE: On Nov 16, 2010 PETD technology was named one of five innovation award winners of the ‘GE ecomagination Challenge: Powering the Grid’ For wind turbine blade deicing.

Integrated Design Variables

Integrated Design Variables: Ocean: Blade length, speed and distance to ocean surface (spray). Land: Altitude (air density) and moisture

Meteorological parameters: (NASA's LEWICE Ice modeling software for predicting icing conditions in aerospace works well for wind turbines)

PETD-Enabled Wind blades for any conditions

In over a decade of research, development and extensive testing of PETD technology in aerospace the Petrenko research team has created a powerful set of software tools to model PETD. These tools provide the ability to design PETD applications quickly and with a high degree of confidence, for hundreds of different materials, blade shapes and environmental conditions.

PETD-I

PETD concentrates a “smart,” precise, high power pulse to the ice/substrate interface for between .01 - 4 seconds to heat a minimal layer of interfacial ice to just above the melting point causing the ice to slide off a resulting thin water film.

"An ice surface has a high electric charge. Ice doesn't simply cake onto surfaces, it bonds in three ways: via the hydrogen atoms themselves, via an electrostatic bond caused by the current and via comparatively weak van der Waals forces.

There is no surface coating which can suspend those three forces. That is why the search for ice-phobic coatings has failed. PETD melts just a few microns of the ice interface and gravity does the rest." - Dr. Victor Petrenko

SPECIAL NOTE: On Nov 16, 2010 PETD technology was named one of five innovation award winners of the ‘GE ecomagination Challenge: Powering the Grid’ For wind turbine blade deicing.

Pulse Electro-Thermal Deicing (PETD) (technical paper)

Engineering Tools

Proprietary Mathcad/COMSOL software tools are used to design and model tile size, shape placement and pulse delivery. Intelligent integrated tile design:

○ Provides incremental deicing pulse delivery system balanced with power availability.

○ Allows for blade flex and perfect conformance to airfoil shape.

○ Matches coefficients of thermal expansion of tile and blade materials to minimize thermally induced stress.

Adhesion: The preferred laminate has excellent adhesive quality.

PETD Tiles

Proprietary PETD Tiles Material: The optimal tile material is a thin composite laminate (.25 to .5mm thick) Application: 3 to 5 ft2 tiles are laid in a series along the leading edge of the air foil. A bank of ultra capacitors Maxwell or Nesscap provide power to the tiles. Life expectancy: Where the maximum imaginable heating cycles is 10,000 per year, the life expectancy the PETD material components is at least 50 years.

Low Power Consumption

Low Power Consumption A 1-2 second 50kW/m2 pulse (average) is required per heating cycle. Under the most serious icing conditions, a heating cycle every 10 minutes uses in average power density of 83W/m2 to 167W/m2.

167W/m2 x 150m2 = 25kW Example: The target area of a 50m blades is about 150m2. Under heavy icing conditions such a turbine would use an average of less than 25kW.

System Overview Diagram

System Overview For most existing sites, only the outer third of the blade requires ice protection tiles.

Other Attempts Blade De-Icing

Why Other Solutions Don't Work

Thermal Heating panels/tape● Too slow. Heat dissipates into ice and

blade● Incomplete de-icing ● Patches fall off due to thermal expansion,

material incompatibility● Excessive power consumption

Hot Air Blade Heating● Requires plant shut down ● Incomplete de-icing ● Too slow. Heat dissipates into ice and

blade● Excessive power consumption

Ice-phobic coatings

● Years of testing has not yielded success● Icing occurred even on coated surfaces● Materials degradation, coating becomes

porous