Gateway West Transmission Project

Planning studies required by the Western Electric Coordinating Council (WECC), will continue into 2009, evaluating the best way to coordinate the electrical needs of the region.

The list below includes the six segments of 500-kV transmission lines planned, plus additional 230-kV lines; however, the WECC studies could alter these plans.

There are six, 500-kV segments planned at this time:

• The first segment will begin at the proposed Hemingway transmission station, southwest of Boise and will connect to Idaho Power’s Midpoint Station north of Twin Falls.
• The second segment will start at the Hemingway Station and connect to the proposed Cedar Hill transmission station south of Twin Falls.
• The third segment will connect the Midpoint Station to the Cedar Hill Station.
• The fourth segment will connect the Midpoint Station to the Populus transmission station in Southeast Idaho.
• The fifth segment will connect the Cedar Hill Station south of Twin Falls to the Populus Station.
• The sixth segment will connect the Populus Station to the Aeolus Station.
• Additional 230-kV lines will connect the Jim Bridger and Dave Johnston generation facilities in Wyoming.

Electric Highways

In order to bring electricity to our customers, Idaho Power needs to transport electrical power from traditional generating resources like hydro-electric dams and thermal power plants as well as other merchant facilities, across long distances.

To do that, high voltage transmission lines are used, which would be the equivalent of a freeway system that moves vehicle traffic. Once the electricity arrives at a community, it goes to a substation, where the voltage is stepped down – like an off-ramp from the freeway and slowing down for street traffic. From there it goes out on distribution lines – or feeders – to serve local businesses and homes.

The whole process can take electricity from very high voltages down to the 110 or 220 volts that most residents are familiar with. And it all happens in less than a second!