MidAmerican Energy Holdings Co. has signed an agreement to acquire the 81-megawatt Bishop Hill II wind project near Galva, Ill., from Invenergy Wind LLC. This project, which currently is under construction, will feature 50 General Electric 1.62-megawatt wind turbines when it is completed in the fourth quarter, MidAmerican said. Ameren Illinois will purchase the electricity from the project pursuant to the terms of a 20-year power purchase agreement.