The deal is for 24 V90 3MW and 31 V90 1.8MW turbines, which will be built at Solano 3. Delivery is planned for the second half of 2011, with the project set to come online in 2012.
Vestas turbines are in use on the other two parts of the project. Solano 1 uses 23 Vestas V47 660KW and Solano 2 uses 29 V90 3MW turbines.
Most of the order will be manufactured in the US, apart from the V90 3MW nacelles which will be built in Denmark.
Speaking in 2008 about the benefits of a utility owning a wind project, SMUD spokesman Jon Bertolino said: "We have certainly found that owning the project site produces economic advantages for us. We're actually able to own it and operate it cheaper than what we're seeing on the open market."