All of the projects are in Iowa and use GE 1.5MW turbines. They are Carroll (150MW), Charles City (75MW), Victory (99MW) and Walnut (153MW).
EnXco said the deal includes project oversight and remote monitoring from the company's control centre in Minnesota.
Last month, enXco was handed a similar O&M deal by MidAmerican for 456MW of projects in Wyoming and Oregon. MidAmerican has a record of doing its own post-warranty maintenance.