Vestas V47 turbines have 660 kW nameplates. Gamesa says it can upgrade the turbines to 710 kW.

Vestas was quite successful selling its V47 wind turbines almost two decades ago. The company erected almost 6,000 of the 660 kW units around the world. About 1,600 are in the U.S. As they reach the end of their useful design life, owners might have faced two options: either let the equipment stay running if it’s still capable of doing so, or tear it down and replace it with a larger turbine, a process often called repowering.

Gamesa engineers now propose a third option: recondition and upgrade the turbine to 710 kW with an ROI of about five years and 10 years more working life. “An overhaul would upgrade a V47 with new converter and controls as well as replace the older RCC generator with a more modern double-fed induction version,” says Gamesa Global Services Sales VP Fernando Valldeperes at a recent meeting. “The work would also include a new coupling on the high speed shaft and a torque limiter, along with new cabinets in the nacelle and on the ground.” Blades could also be replaced if necessary.

Structural improvements would include a reinforcement of the frame and a new reinforced gearbox, upgraded SCADA, and improved control algorithms. The upgrade comes with a two year warranty. The advantages of doing so, says Valldeperes, include grid code compliance, active and reactive compliance, and reduced maintenance cost.

The company says it is next considering upgrades to its own 850 kW and 2.0 MW series machines.