SDG&E files with regulators, documenting need for Valley-Rainbow project

SAN DIEGO, Oct. 5, 2001 – Whether or not new power plants are built in the region, the construction of the proposed $271 million, 31-mile Valley-Rainbow Interconnect transmission power-line project by San Diego Gas & Electric (SDG&E) in southwest Riverside County remains critical to the state’s future electric reliability, according to testimony the company is filing today with the California Public Utilities Commission (CPUC).

When completed in 2005, the project, which is currently under regulatory review by the CPUC, would link SDG&E’s system at Rainbow and Southern California Edison’s system in Romoland and transport enough electricity to light more than 700,000 homes.

“Due to the ever-changing landscape of the state’s electric picture, we decided to test the need for the 500,000-volt Valley-Rainbow Interconnect by carefully exploring several different scenarios involving the need for the line,” said James P. Avery, senior vice president of fuel and power operations for SDG&E. “In each case, the common conclusion was that this project is required in 2005 and grows in importance every year thereafter. In our view, SDG&E’s CPUC-mandated obligation to serve its customers with a reliable source of energy must involve the construction of this project.”

The scenarios projected a 46-megawatt (MW) shortfall for electricity in San Diego in 2005 growing to 199 MW in 2006 and increasing every year thereafter. A megawatt is enough electricity to support between 700 and 1,000 homes.

The testimony by company experts explains that SDG&E is situated in an electrical “cul-de-sac” served by only two transmission pathways. The failure of one of these transmission paths would result in just one major connection between the company’s 1.2 million customers in San Diego and southern Orange counties and the state’s power supplies. The Valley-Rainbow project would provide a third pathway, making SDG&E customers less vulnerable to outages or blackouts. This new transmission interconnection also would minimize the risk of SDG&E blackouts due to storms, earthquakes or possible acts of sabotage that could temporarily cripple the system.

SDG&E’s testimony also examines scenarios involving the proposed construction of additional power generation projects in San Diego and Baja California, Mexico. According to the California Energy Commission, there are more than 37,000 MW of new generation proposed in California and northern Mexico, with about 7,500 MW proposed for the San Diego and northern Mexico regions.

“It is important to point out that there are no guarantees that these proposed power plants will ever be constructed,” Avery said.

Once completed, the Valley-Rainbow Interconnect could connect the state’s sources of power with a pathway that can accommodate as much as 1,000 MW.

Customers in San Diego would not be the sole beneficiaries of the Valley-Rainbow Interconnect.

“Providing an enhanced electric pathway linking power sources to the north and south should help put downward pressure on electric costs by enhancing competition while bolstering reliability for all electricity users in the region,” Avery said.

Also, in the event that Southern California Edison’s existing 500,000-volt transmission system is interrupted, the Valley-Rainbow Interconnect would serve as an emergency backup for southwest Riverside County.

San Diego Gas & Electric is a regulated utility that provides service to 3 million consumers through 1.2 million electric meters and 740,000 natural gas meters in San Diego and southern Orange counties. SDG&E is a subsidiary of Sempra Energy (NYSE: SRE – news), a Fortune 500 energy services holding company based in San Diego.

SOURCE: San Diego Gas & Electric

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