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May 21, 2012 (San Diego) – Five San Diego County transmission projects are among 30 identified transmission projects needed to maintain grid reliability that were approved by the California Independent System Operator Corporation Board of Governors in the 2011/2012 Transmission Plan. The local projects are:

·         Reconductor TL631, El Cajon – Los Coches

·         Replace Talega 138/69 kV Bank 50

·         TL633, Bernardo – Rancho Carmel 69 kV Reconductor

·         TL642B, Sweetwater – Montgomery Tap – Terminal equipment

·         TL695B, Talega Tap – Japanese Mesa Recondutor

The Plan also affirms, for a second year, that previously approved major transmission projects remain sufficient to meet California’s goal of using renewable resources to supply 33 percent of power use by 2020. ISO analysis shows approving additional green transmission at this point could potentially lead to overbuilding and stranded investments.

While remaining prudent, the ISO is committed in evolving its planning processes to identify and approve the least cost options that enhance grid reliability. This effort is made possible by collaborating closely with the California Energy Commission and California Public Utilities Commission. The energy agencies conducted research and analysis that identified renewable-rich, remote areas of California where new transmission upgrades would likely occur. This aided the grid planning analysis.

The ISO 2011/2012 Transmission Plan is the result of a 15-month process in which the ISO and its stakeholders undertook a comprehensive study of California’s grid and generation needs. The Plan assesses whether additional transmission is needed to: 1) maintain power grid reliability; 2) enable policy-driven resources (i.e., clean energy delivery); and 3) relieve transmission bottlenecks to reduce costs. Project investments approved total $691 million.

Flexible capacity requirements

Development of next year’s plan is already underway and will ascertain the level of flexible generation capacity to meet the changing operational needs of the grid as more and more renewable power is added to the system. Traditional natural gas plants provide flexible capacity which is essential in balancing fluctuations of wind and solar power as well as supporting and maintaining local area demand.

“The needs of our grid are becoming more complex as California strives to reach important clean energy goals. ISO operators need the right mix of resources going forward to reliably manage the power system and that includes conventional generation that can quickly ramp up or down to complement the variable flow of renewable power,” said Neil Millar, Executive Director, Transmission Planning. “Looking forward, the ISO is concerned this unique operational tool may diminish over the next five years as a result of a once-through cooling regulation that may prompt retirements of some gas-fired power plants.”


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