Two projects are planned for sites near Zaragoza, northeast Spain, with the third set for a site near Cuenca, in the east of the country.
Installation will commence in March 2019, after which Nordex will also provide service and maintenance for up to three years.
Nordex was unable to name the customer, but said it was a repeat investor with whom Nordex had compelted several projects previously.
The turbines will be installed at hub heights ranging between 84 and 112.5 metres, depending on the location, the manufacturer said.