Google and Citi will invest $102m each for the construction of the 168MW Alta V project, being developed by Terra-Gen Power in California, US.
The funds will be used to develop the second phase of the 1,550MW Alta Wind Energy Center (AWEC).
This investment brings the total investment of each company to $157m and the companies will now hold leveraged leases for two phases, totalling 270MW.
Citi has also underwritten the equity financing for Alta Projects II-V, totalling 570 MW.
Construction of the first five projects with a total capacity of 720MW is complete and another 300MW is expected to be developed, bringing the total capacity of AWEC to 1,020MW by the end of this year.
Under a power purchase agreement, AWEC will sell the whole of its 1,550MW of wind energy capacity to Southern California Edison.
The AWEC projects will use the new transmission line, which will be developed as a part of the 4,500MW Tehachapi renewable transmission project.