Gamesa will manufacture 11 G90 2MW turbines for the 22MW Glen App project located near Cairnryan in Dumfries and Galloway.
Delivery is expected in Q3 with completion due in January 2017.
ScottishPower, a subsidiary of Spain's Iberdrola, has also placed an order for 35 G52-850kW turbines for the Hare Hill extension project near Cumnock, East Ayrshire.
Gamesa said height restrictions at the site limited the size of the turbine to between 44m and 65m. The turbines are now only produced "on demand in ad hoc situations", the manufacturer said.
ScottishPower said the decision to use the smaller turbine was a "landscape judgement". The turbines will be expand the existing 13MW project comprising 20 Vestas V47 660kW turbines. A spokesman for ScottishPower the decision to use the smaller Gamesa turbines was to ensure they fit with the rest of the site.
In May 2015, ScottishPower placed a 239MW order with Gamesa to supply 94 G114 2.5MW and two G90 2MW medium-wind turbines for the 239MW Kilgallioch project, also in southern Scotland. Orders between the two companies now total 600MW.