A new, 19-turbine wind farm in Hancock County, which has the capacity to supply the average energy needs of 18,000 homes, has been completed. Boston-based First Wind says its 34-megawatt Bull Hill project has also begun commercial operations. It’s located on the ridges of Bull Hill and Heifer Hill in Hancock County. With the facility operating, Hancock County and Eastbrook will receive an average aggregate tax payment of about $100,000 annually for the next 20 years and an additional $240,000 annually in community benefit payments, for a total of more than $7 million. The utility NSTAR and First Wind have entered into a 15-year fixed-price contract for the output from the project. Construction started earlier this year and was completed ahead of schedule.