CAISO’s Transmission Plans Focus on Reliability

By Published On: March 27, 2009

The California Independent System Operator’s final 2009 Transmission Plan includes more than $390 million of investments in 45 new transmission infrastructure projects to ensure the reliability of the statewide power grid. The CAISO board was briefed March 26 on the transmission plan, which lays the foundation for expansion of grid operator’s system. While focusing on reliability, the transmission plan incorporates other key initiatives to meet regulatory, planning, and technical requirements, according to Laura Manz, CAISO’s vice president of market and infrastructure development. These include planning for new transmission lines to supply renewable energy to the grid to help meet the state’s 20 percent and 33 percent renewable portfolio standard and greenhouse gas reduction targets. It also seeks to address transmission impacts due to regulations governing once-through cooling power plants, a 2010 probabilistic planning reserve margin study, optimizing support for the Tehachapi transmission project, and a preliminary locational marginal pricing study using the Western Electricity Coordinating Council’s 2017 base case. Transmission upgrades are expected to enable CAISO to comply with both the North American Electric Reliability Corporation’s reliability planning standards for California and the Federal Energy Regulatory Commission’s transmission planning principles, officials said. The transmission plan consists of four major components: a summary of technical studies conducted by CAISO during the 2009 planning cycle; contingency conditions and mitigation plans; new projects and studies; and a roadmap outlining key initiatives for the 2010 transmission planning process. In addition, CAISO received 134 project proposals for consideration from stakeholders, 45 of which are incorporated in the plan. Last year, CAISO conducted a 10-year assessment of its entire system to ensure compliance with NERC reliability standards, using summer on-peak/off-peak models. CAISO identified over 200 criteria violations and proposed over 160 mitigation plans to address them. The staff worked both on the 2009 and 2010 transmission plans, with the former reviewed by the board this week. On March 24, the CAISO conducted a workshop with stakeholders to lay out a roadmap and parameters for the planning process for the 2010 transmission plan. CAISO spokesman Gregg Fishman said the 2010 plan includes assumptions about load, new transmission projects that will be built, new generation coming online, and what old generation might retire this year. The CAISO is considering 11 study requests it received from the 2008 transmission planning cycle: seven economic projects, one merchant transmission facility, one load interconnection, and two reliability projects, said Paul Didsayabutra, senior regional transmission engineer. The transmission projects would deliver solar, wind, and geothermal energy from remote areas like the Mojave Desert and Imperial Valley to urban load centers in Southern California. They also aim to improve system reliability and operate more economically, as well as relieve congestion in constricted areas like San Francisco that lack sufficient generation to serve their loads. The CAISO expects to have a complete list of approved projects by June and will issue a request for proposals August 15 with a November 30 deadline, Didsayabutra said. While the CAISO won’t determine whether to approve generation versus transmission projects, it must decide how to treat specific generation projects that are submitted for connection to its control area in view of transmission system upgrades, officials said. “If it takes 10 years to build a transmission line and two years for generation somebody has to step up so that generation will be there when it’s needed,” said Gary DeShazo, the CAISO’s director of regional transmission north. For example, the San Francisco Public Utility Commission has proposed building a transmission project to improve system reliability. However, CAISO needs to assess the commission’s project request as part of San Francisco’s unresolved transmission and generation needs, DeShazo said. CAISO plans to conduct technical studies on reliability and other issues this year using the California Energy Commission’s load forecast over a ten-year timeframe from 2010-2019, Didsayabutra said. Regulators and utility representatives stressed that load forecasting is fraught with uncertainties. For example, in some areas of the Central Valley PG&E projected extremely high load growth that didn’t occur, perhaps due to the economic recession. Demand shifts around in two to three-year growth cycles, stakeholders said. Forecasts are driven by population studies, not economic cycles. However, demand is expected to be low during a recession but could grow by 3.5 percent if the current economic downturn ends this year, stakeholders said. CAISO utilizes the California Public Utility Commission’s energy efficiency forecasts in projecting load growth for transmission planning, Didsayabutra said. However, the CPUC cautioned the CAISO against using its latest energy efficiency forecasts because it is still receiving comments from utilities and anticipates revising them. Moreover, using forecasts for uncommitted energy efficiency projects which won’t occur until 2012 at the earliest--if ever--may not be prudent in forecasting for annual transmission planning, the CPUC said.

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