The contract is for 94 G114 2.5MW and two G90 2MW medium wind turbines to go to the Kilgallioch wind project in southern Scotland. According to Gamesa the project will be commissioned in Q1 2017.
The project will be the UK's second-largest onshore wind farm after the 539MW Whitelee wind farm, which is in the same region.
It includes a five-year service agreement.
In a statement, Keith Anderson, ScottishPower Renewables CEO, said: "Kilgallioch windfarm will become our second largest windfarm in the UK and this year marks a real milestone as we approach 2 GW of installed onshore wind capacity."
ScottishPower received approval from the Scottish government to build the project in February 2013.
At the time, ScottishPower said the installation would cost more than £400 million, with work commencing in late 2014 or early 2015. It hopes to bring the wind farm online within the next two years.