Organized Labor

• Testing Begins on System that Will Supply Up to 10 Percent of City’s Electric Power

By Paul Burton, Contributing Writer

Construction crews have completed the San Francisco substation at 23rd and Illinois Streets that will receive electricity from the city of Pittsburg via a 53-mile-long high voltage direct current (HVDC) transmission line—the TransBay Cable.

Cupertino Electric served as prime contractor on the TransBay Cable Project and installed the AC and DC yards at the Pittsburg and San Francisco sites, the reactor yards, the transformers and the converter hall, as well as provided and installed all supporting steel, bus work and insulators. The contractor’s Marketing/Communications Manager Autumn Casadonte said CEI also procured and installed all the copper and fiber control cables for the converter hall. She said 16 members of IBEW Local 6 worked on the project, including Journeyman, Lineman, and Apprentice Lineman members.

Another union electrical contractor, Rosendin, did the underground work and the shell for the converter hall that houses the equipment that converts the DC current sent across the transmission cable back to AC. Members of IBEW 1245 working for CAM Contractors and Prysmian were also on the job. Local 1245’s newspaper, The Utility Reporter, featured the project in its November issue. Reporter Eric Wolfe explained that, “The San Francisco converter station is located just across the street from PG&E’s existing Potrero electric substation. When the power arrives from Pittsburg it will come through the DC yard switches at 200,000 volts and into the converter hall, where it will be converted to 200,000 volts AC. It then travels to transformers, which step it down to 115 kv, then hits potheads and goes across the street to Potrero substation and then sent on its way to end-use customers.”

Wolfe reported that crews from Local 1245 contractor Prysmian worked outside the converter building in July performing a “high pot jacket test” on a spool of cable, running a 20kv DC current through the jacket/semiconductor to make sure there were no rips in the outside jacket. Local 1245 members working for CAM Contractors did the linkage to switches they installed, he wrote.

Prysmian recently completed laying the transbay cable along a shallow trench on the San Francisco Bay floor, using a hydro-plow to blast and remove silt. The cable has been connected and the system was energized on Dec. 7.

Garrett Evans, General Manager for Pittsburg Power, which owns and will operate the system, said the company had been doing testing on the Pittsburg side for the past three months. The converter hall at the SF substation that converts the DC current back to AC has been completed and testing has been ongoing since early November. He said the job was completed ahead of schedule. It had been set to go online in mid-March, but will begin commercial operation Feb. 1. He said, “The crews were amazing, and did a great job.”

“From Pittsburg to Potrero Hill, our team successfully delivered high-quality technical services within a tight schedule without any injuries,” Cupertino Electric Vice President John Curcio said. “We don’t believe in compromising safety for any reason. The TransBay Cable Project is a great example of our ability to successfully execute large-scale, technically challenging and unique electrical projects on time and on budget.” Cupertino Electric assisted with the initial test of the pre-commissioning/pre-start-up. Ms. Casadonte said that because the testing work is highly specialized, the developer, Siemens Power Transmission & Distribution, Inc., did the final testing at the site.

Evans said the cable adds power to San Francisco and the Peninsula, and could provide up to 10 percent of electric power for city. “It adds to the reliability of the electrical grid,” Evans said. He added that the new system will replace some of the power generated by the nearby Potrero Power Plant which environmental groups like SF Power say needs to be shut down because it is “the single largest source of polluting air and greenhouse gas emissions in San Francisco, [and] is hazardous to the health of our families and neighbors.” Evans said the substation in Pittsburg receives energy from a variety of sources, including renewables like wind power, hydropower, and geothermal, as well as natural gas.

The project was chosen by the California Independent System Operator (CAISO) to provide reliable energy to the City of San Francisco. The CAISO decided that the northern San Francisco Peninsula needs an additional transmission line to ensure energy reliability in 2010 and beyond. The Pittsburg side broke ground in Nov. 2007; groundbreaking in San Francisco began in January 2008.

Organized Labor first visited the job site in October 2008. At that time, Project Consultant and Electrical Engineer Wilhelm Napier explained that the project involves construction of two converters on each side of the Bay. On the Pittsburg side the AC will be converted to Direct Current to travel on the cable under the San Francisco Bay, then be converted back to AC and tied in to PG&E’s station across 23rd Street. Napier said that conversion from AC to DC and back to AC was an efficient system because direct current only requires two cables instead of the three required for AC and was less expensive to build. The direct current also does not have any loss of electricity or electromagnetic radiation as it travels over the cable. Concern for the environmental impacts of the electromagnetic radiation on sea life was a factor in choosing the DC transmission system. Siemens also developed new technology for the two substations, Napier said.

Work was done under a Project Stabilization Agreement, similar to a PLA but mandating that all contractors are union contractors. All San Francisco construction unions signed the PLA; most participated in the project. Subcontractors included Roebbelen Construction, Stroer and Graf for the pile driving, AC Jones for grading work, and Cleveland Wrecking. Cleveland Wrecking is a signatory to Master Agreements with the Operating Engineers and Laborers unions and worked on the demolition of the AirGas and DHL buildings that occupied the site. Laborers Local 67 members employed by Sterling Engineering worked on the abatement of lead paint at one of the nearby buildings. There will also be some permanent jobs maintaining and operating the stations.
The TBC will have the capacity to transmit 400 megawatts of electrical power. It is designed to reduce the need for proposed in-city generation in the city of San Francisco, decrease transmission grid congestion in the East Bay, increase the overall security and reliability of the electrical system, and provide potential savings to ratepayers, according to the developer.

San Francisco will also benefit not just from the extra source of power, but also from $1 million in annual rent that developer Trans Bay Cable LLC will pay the Port of SF and $5.5 million for shoreline improvements and $3.5 million to the SF Public Utilities Commission for sustainable energy development.