Competitive Transmission Transource® is a partnership between American Electric Power (AEP) and Great Plains Energy (GPE) focused on the development and investment in competitive electric transmission projects across the U.S. Transource is a member of three regional transmission organizations - the PJM Interconnection, the Midwest Independent System Operator (MISO) and the Southwest Power Pool (SPP) - which together serve all or part of province of Manitoba in Canada.