The order is for 25 V80 2MW turbines, which are designed for high wind sites. They will be installed on the Camster wind farm, in Caithness.
E.ON project manager Dean Guy said: "We see onshore wind as an important part of the energy mix here in the UK, and Camster wind farm is an important part of that."
In November last year, RES ordered 14 V80s for a project in North Ayrshire.
Recently there have been a number of V80 orders from Chinese developers.
This includes a 48MW deal from GSI for a project in Huitengxile, in the Inner Mongolia Autonomous Region, and an 48MW order from Longyuan for a project in Zhongmen, Putian County, southeast China s coastal province of Fujian