The social media firm said it originally began developing the wind farm with developer RMP Access, but the rights to the project were transferred to MidAmerican in the spring.
Facebook said the wind farm is expected to add more power to the grid than the data centre will require when it starts handling traffic in 2015, therefore securing renewable energy certificates for the facility.
Work has now started on the Wellsburg wind farm, with completion expected in 2014. It was revealed earlier in November that Siemens 2.3MW turbines will be used on this, and four other wind farms being developed by MidAmerican across Iowa.
In April, MidAmerican was given the green light for the development of 1.05GW of wind power in the Midwestern state by the end of 2015.
Facebook reiterated its commitment to reaching its target of sourcing 25% of its power from renewable sources by 2015.
