Photo: Line crews connect lattice transmission structure to an Erickson Air-Crane during the Path 15 construction project.

Photo by David Christy

WAPA marks 20th anniversary of Path 15 transmission line

What a difference two decades can make. In 2003, Americans were recovering from the 9/11 attacks, rebounding from a recession caused by the dot-com bubble and beginning to see the rise of subprime mortgages.

At the same time, California reeled from an energy crisis. The demand on the Golden State’s power grid had accelerated in the late 1990s, as the state’s population and tech communities exploded. Together with cooler winters in Oregon, where demand for energy to heat homes had also increased, California power providers needed a solution to handle the increased energy loads that were quickly reaching maximum capacity.

Enter: The Path 15 project

During the 1990s energy crisis, as the California Independent System Operator faced increased demands on its transmission system, the entity was also challenged with securing financing and partnerships to expand the state’s electrical capabilities. An analysis of the afflicted transmission lines in northern and central California determined that more than 500 miles of transmission line capable of carrying up to 500 kilovolts would be needed  to relieve ongoing constraints.

WAPA’s Sierra Nevada region Vice President and Operations Manager Bryan Griess recalled the challenges vividly.

“At the time, I was working for another company that had power transmission in northern California,” Griess remembered. “We were aware that WAPA put out the request for participants to take part in the Path 15 project. WAPA joined forces with them and built the line between two Pacific Gas and Electric substations. I had known about the need for the Path 15 project through previous transmission planning studies.”

Griess, who was then assistant general manager for California’s Joint Powers Agency, was already charged with constructing and maintaining transmission lines in the state. As the energy crisis grew more dire, Griess said it was evident the federal government needed to step in.

“The reason WAPA ended up building the line is because the California ISO knew of the system constraints, but they couldn’t get anyone to fix it,” he said. “It became pretty evident they needed the federal government to get involved through a public-private partnership to get this thing off the ground.”

“They had been looking to fix Path 15 for many years,” he continued. “Then, WAPA got involved, pushed it forward and got it done.”

WAPA steps in

As a result of the ongoing challenges, on May 28, 2001, then-Secretary of Energy Spencer Abraham directed WAPA to complete its planning to relieve the Path 15 constraints and determine whether outside parties would be interested in helping finance and co-own the necessary system additions, including transmission lines. That level of interest would contribute to the department’s final decision to build the additions necessary to relieve the system congestion.

The Department of Energy published a Federal Register notice in June 2001 on the ambitious plan. WAPA, coupled with both public and private partners, would embark on a visionary initiative — the Path 15 High Voltage Power Transmission Line Project. The estimated $300 million project had a goal of providing relief to what had become a bottleneck of power transmission. At the time, existing lines owned and operated by PG&E had been quickly pushed to their capacity.

Immediate interest came from PG&E and CAISO, and with each entity in agreement that WAPA would be the project manager, the Path 15 project had taken a giant leap forward to becoming a reality.

SN’s Director – Transmission and Construction Timothy Alme, who was based in the Desert Southwest region during Path 15’s adoption, assisted the system protection and communications groups involved in the project.

“We worked to develop the protection schemes that were required for WAPA and substation owners to coordinate the system project equipment,” Alme recalled. “My role was small, but I remember all the team members from that time like it was yesterday.”

Alme said that study after study showed the need for transmission line expansion.

“The studies were quite clear: to get rid of those bottlenecks, you needed capacity. The only way to build capacity is to get more transmission lines,” he explained. “Our planning and engineering teams saw that and figured out that unless they built that line, the problem would remain. And this would drive prices even higher than what California was already faced with.”

The ambitious Path 15 plan would construct an 84-mile, 500-kilovolt transmission line between PG&E’s Los Banos and Gates substations. Additionally, the project required upgrades at the same substations to accommodate the appropriate equipment for the expansion.

Path 15 would also establish a second 230-kilovolt circuit between the Gates and Midway substations. Overall, when completed, the project would increase the south-to-north path rating from 3,900 megawatts to 5,400.

Building a new way

WAPA released a solicitation for transmission line work on Jan. 31, 2003. Four months later, WAPA selected Mesa, Arizona-based Maslonka and Associates for the $87 million contract to construct and complete the nearly 100-mile power transmission expansion, with upgrade contracts and other projects placed on PG&E. The first shovels entered the ground later that fall, and in the autumn of 2004, grid operators energized the Path 15 expansion line for the first time.

While the Path 15 project was successful in alleviating power congestion issues, Griess pointed out that as more renewable energy generation comes online, more transmission lines are still needed.

“We’re still struggling out in the West to get any new transmission built,” he said. “While the California ISO has been somewhat successful, we still need thousands of megawatts of transmission to be built to be able to handle all the renewables.”

Griess continued, “The problems with power transmission haven’t gotten better or worse, they’ve just become different. With the increased use of solar, wind and batteries, we’ve seen new stresses on the system that require more transmission construction.”

Over recent decades, building new transmission lines has proven too big a task for any one entity to manage.

“So, the idea of having the type of public-private partnership that WAPA took part in for Path 15 makes a lot of sense for today’s needs,” Griess said.

Note: The author is a public affairs specialist.

WAPA file photos by David Christy

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Last modified on March 8th, 2024