Seven transmission lines planned in renewable energy-rich Southern California can provide enough capacity to reach the state’s 33 percent renewable energy target, the California Independent System Operator revealed Dec. 15. In a preview of its transmission plan to be released next month, the grid operator also signaled that Pacific Gas & Electric’s Helms Pumped Storage facility is likely to play a pivotal role in integrating higher levels of intermittent renewable energy into the grid. “The good news here is we’ve made tremendous progress these past few years planning out the transmission grid to meet the renewables portfolio standard goal,” said Keith Casey, grid operator vice president of market and infrastructure development. In its planning effort, the grid operator examined numerous scenarios for how the 33 percent goal can be met--including significant placement of smaller distributed renewable generation facilities within utility distribution systems and a high out-of-state supply case--explained Casey. He said that in all of the cases--except for the high out-of-state scenario--the planned transmission lines can meet the state’s 33 percent renewables portfolio standard target. Casey did add, however, that if a large amount of renewable energy is imported, a new 500 kV line from Oregon into California would be needed to meet the 33 percent standard. That line would cost about $1 billion. The state needs $420 million in upgrades to substations and existing transmission lines to integrate the new sources of renewable energy in addition to the seven major lines, according to the grid operator. Another major finding, Casey explained, is that PG&E’s Helms Pumped Storage facility likely would have to be operated more frequently to even out the flows of energy from intermittent wind and solar resources. This would entail building a new line into the Southern Sierra facility to transmit more power in and out. CAISO estimates that line would cost about $1.2 billion. Helms originally was built as a peaking hydro unit--pumping water from one reservoir to a higher one during times of slack electricity use, then opening the gates to generate power during times of high consumption. Now, pumped storage is seen as a method to maximize use of renewable resources that operate intermittently. Wind and solar power that is overabundant at times can be used to pump water uphill to store energy for later use. The plan highlights the potentially greater role of the Helms plant just as PG&E is examining whether to build an additional pumped storage facility. It would be on the Mokelumne River and could be scaled to provide 1,200 MW of capacity at a cost of up to $2.5 billion (Current, Aug. 27, 2010). Meanwhile, CAISO’s board is expected to adopt the grid operator’s new transmission plan in March 2011, according to Casey. He acknowledged the plan would change as time goes by. For instance, the plan incorporates transmission lines that may or may not ultimately be built, such as the Sunrise Powerlink, which faces continuing court challenges. Casey stressed the plan is designed with flexibility in mind. For example, he noted that as the state gradually reduces reliance on out-of-state coal power plants, more renewable energy could be imported over existing interstate transmission lines. In other action, the grid operator’s board approved a 2011 budget that outlines a $189.8 million revenue requirement. That’s down by $5.3 million from $195.1 million this year, a decrease of 2.7 percent. CAISO’s budget sets a grid management charge of $0.791/MWh for the coming year, down from $0.793/MWh this year. CAISO’s board also adopted a strategic plan for 2011-2015 aimed at maintaining the reliability of the state’s grid while integrating an increasing amount of renewable energy into the system in order to improve the environment. “Reliability and cost have been the historical sides of the balance,” said Yakout Mansour, CAISO president, “but now the environment is a solid third in the balance.” He cited clean energy technology trends, as well as state policies and the recent election in which voters turned down a measure to suspend the state’s global warming law. The meeting marked the last for board chair Mason Willrich. His term expires at the end of this month and he said he is not seeking reappointment. “It’s been an amazing journey,” he said. “It’s time for some fresh blood and for me to go off and do other things.” In San Francisco, the California Public Utilities Commission voted Dec. 16 to allow investor-owned utilities to participate in the grid operator’s “convergence” bidding process--trading in energy hedging much like derivatives. The commission also voted to allow utilities to trade in CAISO’s “proxy demand-resource product” market. Those are segments of a wholesale electricity market redesign that has been in place since April 1, 2009.
