The Bonneville Power Administration (BPA) says it is planning new upgrades to substations, equipment and high-voltage power lines for the California-Oregon Intertie. According to BPA, these upgrades will allow the Northwest and Southwest regions to share more surplus energy, which will, in turn, strengthen the transmission grid and provide flexibility.
These improvements coincide with BPA's upgrades and construction of new high-voltage transmission lines within the Northwest to support the growth of renewable energy, such as wind power, as well as to ease bottlenecks in the system, BPA explains.
The California-Oregon Intertie is jointly owned by BPA, Portland General Electric and PacifiCorp. BPA owns most of the transmission capacity on this system and operates the intertie. The lines have the capacity to carry 4.8 GW, but before the upgrades, they often carried less energy due to operational constraints. These improvements will allow BPA to operate the line at the full capacity much more frequently, BPA says.
‘Our electric connection to California and the Southwest is very important to us and our transmission customers,’ says Brian Silverstein, senior vice president of BPA Transmission Services. ‘Strengthening that connection will ensure that we can get energy from where it is produced to where it's needed. It's as important as ever as thousands of megawatts of clean renewable energy sprout up across the West Coast.’
According to BPA, the improvements also benefit the Pacific Direct Current Intertie, another high-voltage line that connects the BPA transmission system to Southern California. The upgrades will also allow BPA to operate that line at its capacity of 3.1 GW more often.
The added transmission capacity may also help relieve generation oversupply situations, such as the one the region experienced this spring. This year, mild temperatures reduced demand, and an abundance of hydropower boosted the supply. In this case, California did not need extra energy from the Northwest, and the interties were not fully utilized. However, the additional capacity could be very helpful during a year with warmer California spring temperatures and less water in the California hydro system, BPA adds.