Duke Energy is seeking approval to modify an existing permit for 57 temporary bridge power generators until the campus is connected to the electric grid. Norton said Duke was not required to submit a separate air permit application for the temporary generators. He said emissions from the plant and temporary generators combined will remain below permit limits designed to protect public health and the environment. Norton said Duke was not required to submit a separate air permit application for the temporary generators. He said emissions from the power plant and temporary generators combined will remain below permitted limits designed to protect public health and the environment.