In 2013, the court ordered Gamesa to pay a €7.5m indemnity to Wobben.
"This sentence endorses our firm conviction that no patent has been infringed," a Gamesa spokeswoman told Windpower Monthly, but the company declined to comment further on details.
The €7.5 million, which Wobben must now return to Gamesa with interest, was dubbed at the time one of the largest damages payment of any patent dispute in Spain.
In the appeal Gamesa argued its so-called 'Safe Mode' storm control technology, incorporated in its workhorse 850kW and 2MW turbines, was different from Wobben's patent.
In wind storms, "the Gamesa system gradually slows turbine revolutions until the machine halts completely", said one veteran wind turbine engineering consultant. "Wobben's system slows the revolutions to prevent overload but does not stop the turbine running; that's what makes it special," he added.
Wobben lost a similar patent dispute with Siemens over the same technology in the UK last year.