The wind farm, being built with an investment of $525m, is expected to reach financial close in 2015 and commence operations in early 2016.
The two firms will co-develop the wind farm until the financial close.
Scheduled to commence power generation early in 2016, the project is under the later stages of development with all major permits secured while the grid and offtake agreements are being finalized.
Ghana Energy and Petroleum Ministry Renewable Energy director Wisdom Ahiataku-Togobo said: "The project is consistent with government policy to increase the contribution of renewable energy in the electricity generation mix.
"The Renewable Energy Act 2011 (Act) provides the necessary legal and fiscal incentives including feed-in-tariff (sufficient security) to ensure return on investment by Independent Power Producers."
In addition to managing the construction, Mainstream will manage the operations and maintenance of the wind farm for its lifecycle.
Mainstream chief executive Eddie O’Connor said: "The AyitepaWind Farm is well advanced and can be generating electricity in less than 18 months from now. No other generation technology can match that in terms of speed of delivery."
NEK chief executive Dr Christoph Kapp said: "This project will not only contribute to a sustainable, clean and independent production of electricity, but will also be accompanied by a lot of social benefits and improvements for the local population such as labour, better education, water supply and electrification for nearby villages and towns."
Ghana’s total electricity generation capacity currently stands at 2,000MW.
Image: Mainstream Renewable also operates Jeffreys Bay wind farm in South Africa. Photo: © 2014 Mainstream Renewable Power.
