Photos Existing transmission lines The photos below show transmission lines ranging from 230 kV to 500 kV. The B2H Project is proposed as a single-circuit, 500 kV facility. Visit Idaho Power’s Design and Construction page to view the proposed project structures. Double-circuit, 230 kV transmission line east of Payette, Idaho PacificCorp 500 kV transmission line near Mayfield, Idaho Double-circuit, 230 kV transmission line east of Payette, Idaho Page: 2 of 3 This website is the joint Boardman to Hemingway Transmission Line Project site. Information contained on this site is approved for posting by Idaho Power. Visit the Idaho Power website.