Mace, Hochtief, Turner & Townsend and Unipart join Amentum, the lead partner.
Nationwide deployment of the reactors will create 100,000 construction jobs.
KenGen will spend Sh8.3 billion to modernise the ageing hydropower plant.
The Tibet Dam is set to outsize the legendary Three Gorges Dam.
Kilifi residents fought plans to build a $5 billion plant in their backyard.
The Chinese-funded Orpower 22 power plant will take 17 months to complete.
The new plant is expected to add 80.3MW to the national grid.
The Vipingo power plant is projected to cost around Sh2.5 billion.
The deal paves the way for Kenya's first waste-to-energy plant.
The solar photovoltaic (PV) plant will be set on 80 hectares of land.