Zond Development Corp. will supply MidAmerican Energy Co. with 45 MW of wind-generated power per month for 20 years. Terms of the agreement were not released, but Zond will begin supplying energy within three years of regulatory approval. The contract helps fulfill the utility's alternate energy requirements under Iowa law. Zond will generate the power from about 150 wind turbines planned for Buena Vista County. The windmills will interconnect with the MidAmerican transmission system at a nearby substation.