The Danish manufacturer said the deal covered the upgrade of the production performance of "hundreds of turbines".
PowerPlus was launched by Vestas at the American Wind Energy Association's annual conference in Las Vegas in May and is designed specifically for the US market, where the low cost of electricity is a key driver for greater efficiencies.
EDPR has a considerable number of Vestas turbines in its portfolio, with the companies agreeing a 1.5GW framework agreement in 2010.
The modifications to existing turbines are intended to increase power output by up to 5% through power uprating, extending the cutout speed and implementing aerodynamic upgrades.
It is applicable to V82-1.65 MW, V90-1.8 MW and V100-1.8 MW turbines. The 1.8MW can be uprated to 2MW and the 1.65MW turbines to 1.8MW. This should mean an annual output increase of 1-4%.
The extended cutout is a modification to the control that increases the turbine's maximum wind speed limit from 25m/s to 30m/s. This can result increase annual output by 0.5-2% and can be carried out on the V90-3MW and the V100-1.8/2MW turbines.
The aerodynamic upgrades consist of "vortex generators", which are small fins that are attached to the blades to improve their aerodynamics. The addition of this upgrade can mean an output improvement of up to 0.8%. This is available for the V82-1.65MW.