Pseudo-tie Pilot Sends More Renewable Power to California
Gives Grid Access to Green Generation Located Out-of-State
Folson, CA, June 16, 2010 - The California Independent System Operator Corporation (ISO) began accepting eight megawatts of clean, green solar power on June 15 from a new photovoltaic farm near Boulder City, Nevada under a unique arrangement known as a “pseudo-tie.” The ISO employs the pseudo-tie transmission arrangement to allow power plants located outside the California ISO to deliver electricity as if the generator was located in, or directly connected to the ISO. The Copper Mountain Solar is the first ISO pseudo-tie pilot with an out-of-state renewable resource. Sempra Generation’s Copper Mountain Solar farm, when fully developed, will produce 48 megawatts of power which will be delivered over the ISO-controlled grid to Pacific Gas and Electric.
“We are working very hard to integrate more renewable resources into the California ISO operation,” said Dr. Keith Casey, ISO vice president, markets and infrastructure development. “The Copper Mountain Solar pseudo-tie pilot will eventually supply nearly 50 megawatts of green energy. We will use the pilot project to test and validate our systems and procedures for managing out-of-state intermittent resources.”
Most of the wind and solar capacity to serve California is in-state development. However, renewable development is also increasing out-of-state. Managing these resources efficiently helps meet renewable goals while maintaining grid reliability. The ISO is developing a dynamic transfer policy that will help define how the ISO and neighboring grid operators can move and track electricity as needed. The ISO will bring a proposal to its Board of Governors later this year. The ISO will use what it learns from the Copper Mountain Solar pseudo-tie pilot and two other pilots to develop the dynamic transfer policy.
The ISO currently has two other pilot pseudo-tie arrangements. The Sutter Energy Center north of Sacramento is tied to the ISO grid by lines controlled by another balancing area authority. The New Melones hydroelectric plant exports power out of the ISO controlled grid to another balancing area authority. In both cases, the pseudo-tie arrangement allows for the most efficient use of the power grid.
The California ISO operates the state’s wholesale transmission grid, providing open and non-discriminatory access supported by a competitive energy market and comprehensive planning efforts. Partnering with more than 90 client organizations, the ISO is dedicated to the continual development and reliable operation of a modern grid that operates at the least cost to the benefit of consumers. The ISO bulk power market allocates space on transmission lines, maintains operating reserves and matches supply with demand. Recognizing the importance of global climate change, the ISO welcomes new, advanced technologies that will help meet the energy needs of 30 million Californians efficiently and cleanly. The ISO is a nonprofit public benefit corporation.