Blade

Blade With Lightning - Proof And Noise - ReductionTechnology
The three blades have independent pitch control DC Motors fed from the grid, along with an independent battery power back-up. The battery back-up is required when there is no grid power available to turn the blade. The machine can be brought to a halt even with the help of one blade turning if the other two fail.
Thus, this unique brake system completely eliminates the need for hydraulic brakes employed on the high speed shaft of the stall type generator, thereby, reducing the stresses in the machine and the wear and tear associated with the hydraulic brake system.
Wind World (India) Ltd. has designed hubs and blades such that the weight of the hub rotor is much lower than other makes; hence, the initial moment of inertia is low. Due to this and the pitch regulation feature, the machine starts generating power at low wind speed i.e., 2.5 m/s whereas other machines start at 3.5 to 4.5 m/s.
Wind World (India) Ltd. WEC's therefore have an advantage of generating higher energy than other WEC's, at lower wind speeds.