In 2012, Bechtel provided engineering, procurement, and construction management services for the Catalina Solar Photovoltaic Generating Facility, a 110-megawatt, alternating-current (MWac) solar plant and associated 7.2-mile (11.6-kilometer), 230-kV transmission line that connects the solar facility to the power grid. The facility, which is owned by EDF Renewable Energy (EDF RE) and TIAA-CREF, is located in Southern California’s Kern County and is one of the largest photovoltaic (PV) plants in the United States. Catalina Solar was built on approximately 1,100 acres (445 hectares) and produces enough clean energy to power about 35,000 homes.
Managing transmission line projects with tight schedules
Owners of major utility-scale projects have big stakes riding on project success. To meet its commitments to investors, utilities, and residents, who are banking on reliable, sustainable energy to power their homes, project owners must make every effort to meet their obligations and deadlines. This was the case for EDF RE, Catalina Solar’s owner at the time of construction.
“Catalina Solar is a strategic project for EDF Renewable Energy as it represents our largest utility-scale photovoltaic solar plant developed in North America,” says Mark Tholke, vice president, West Region, for EDF Renewable Energy.
EDF Renewable Energy had an obligation to supply power to the grid in stages and to accomplish that goal, it needed a transmission line—but it needed it built in a very short timeframe. Bechtel had only nine months to engineer and construct the entire transmission line that would carry the power, along with an accompanying underground fiber-optic communications network.
“During the bidding process for the solar site, we learned that the project was on a fast track,” explains Bruce McKenzie, the project’s construction manager. “EDF RE was about 40 percent done with the design for the transmission line and needed to find a company to build it. Because of the short time frame, many firms would not consider the project. Completing the design and securing required materials to meet the schedule were big concerns.”
With more than 65 years of experience in complex power projects, Bechtel is skilled at developing solutions and sourcing supplies from different vendors. The project team recognized the challenges in meeting the short timeframe and saw an opportunity to start the procurement process before receiving the finished design. Bechtel was confident that a collaborative effort by its procurement and engineering organizations would lead to success. With a well-integrated and coordinated approach, these groups established a process to identify qualified bidders and get subsequent release for fabrication of the longer lead items (poles and hardware) to meet customer needs.
Finding alternate suppliers to meet deadlines
One of the biggest procurement challenges for the Catalina Solar project was obtaining the required steel poles. “When materials are costly, as these poles are, vendors don’t tend to keep huge supplies on hand,” explains Tom Parks, the Bechtel procurement manager for the project. “And the short lead time exacerbated procurement challenges.”
At times like this, Bechtel engineering and procurement professionals get creative. “Since we were constrained on the supply of steel poles, we looked at spun concrete poles as a replacement because they had a much shorter lead time,” McKenzie said. “We knew we could get those poles in 10 or 12 weeks, instead of the 24- to 36-week quotes we were receiving for steel poles.”
Structural limitations prevented the use of concrete poles in all locations, so the team came up with a strategic workaround in which the more lightly loaded tangent poles, which represented two-thirds of the total structures, were specified as concrete. This left a much smaller number of dead-end/terminal structures to be built from steel and reduced the shop load for the steel pole fabricator. Through close coordination with the manufacturer, steel pole deliveries were planned to fall within a window and in an order that would allow the transmission line to be successfully completed.
“We located a manufacturer of the spun concrete poles only 80 miles (129 kilometers) from the site, so we were able to get the poles there on a more timely basis and start the project,” says Parks.
To bring in the steel poles that would eventually be needed for the project, the Bechtel procurement team identified a company in Mexico. “They offered the shortest schedule for building and shipping them,” Parks says. “We placed some of our shop expediting and supplier quality experts in the company’s shop to ensure they would meet our quality standards and schedule obligations.”
Permitting and site access challenges require experienced project management
Bechtel engineering and procurement experts needed to pay special attention to challenges at the building site as well. “We were working in the Mojave Desert, which is a very sensitive environment,” says McKenzie.
Hundreds of field personnel were introduced to and educated on the environmental sensitivities of the site and the associated environmental protection and avoidance measures. Best practices were put in place to protect artifacts, vegetation, and sensitive species like the San Joaquin kit fox, California condor, and burrowing owls.
The Bechtel team also had to work around complex permitting requirements, both building and environmental. EDF RE was responsible for obtaining most of the environmental permits, while Bechtel was required to provide all building permits. Bechtel, in turn, was responsible for ensuring full compliance with the strict requirements of each permit, whether building or environmental, during construction. As the transmission portion of the project wrapped up in December 2012, it became clear that Bechtel’s planning and problem-solving skills were key contributors to the line’s success. “We were able to jump in and support EDF RE to get the project up and running,” McKenzie says. In addition to completing the transmission line, Bechtel completed the 110 MWac solar facility in August 2013.
“Meeting EDF Renewable Energy’s needs was a testament to the team and to the expertise and relationships that have been built over the decades,” says Toby Seay, president of Bechtel’s Power global business line. “With the completion of the Catalina facility, we will help make solar more cost competitive with other sources of energy and will help strengthen the nation’s use of clean, renewable power."
Kern County, California
EDF renewable energy
Scope of services
- Project management
Construction management transmission line completion: 2012
- Engineering, procurement, and construction for 110-MWac PV solar plant
- Engineering, procurement, and construction management services for 7.2-mile (11.6-kilometer), 230-kV transmission line
- Engineering, procurement, and construction management services for 9-mile (14.5-kilometer) fiber-optic communications network
- Initial energization of transmission line within nine months
The plant was designed, constructed, and commissioned in multi-megawatt blocks of various capacities and was completed in two phases, the first consisting of 36 1.44-MWac blocks for a total of 51.8 MWac and the second consisting of 40 1.44-MWac blocks for a total of 57.6 MWac.
The project will operate year-round, producing up to 110 MWac of renewable electric power during daytime hours. The developer has secured a Power Purchase Agreement with San Diego Gas & Electric to supply electricity generated by the project.
The project includes a 7.2-mile (11.6-kilometer), 230-kV transmission line that connects the facility to the power grid.