The certification body has confirmed that Gamesa's structural upgrades and monitoring features can extend the life of the turbines from the standard 20 years to 30 years.
Gamesa said it will now work on applying the life-extension programme to its 850kW and 2MW turbines and even to machines from other manufacturers maintained by Gamesa.
DNV GL said its certification was based on analysis of the design, specifications and applied calculations over the entire life of a G47-660kW turbine, based on its Guideline for Continued Operation of Wind Turbines 2009.
"The ability to extend the useful life of a turbine is a key step in maximising efficiency and reducing costs in the global wind energy market," said Andreas Schroeter, executive vice-president of the renewables certification division of DNV GL.
Gamesa said the extra ten years of operation would make the turbines more profitable over their lifetime.
Enercon recently launched a new 4MW turbine platform that it said will last for 30 years rather than the standard 20 years of most turbines. It is thought to be the first turbine platform specifically developed with this longer life.