California ISO to Conduct Summer Simulation; Grid Test Part of Summer Preparations.

FOLSOM, Calif. -- The California Independent System Operator (California ISO) began a system simulation today, Tuesday, May 3, to test power flows and deliverability of electricity on the ISO grid as well as the ability to handle expected high loads during the peak demand season. The summer simulation will test the grid and electrical resources under normal conditions or a 1-in-2 scenario as well as extreme heat wave conditions or a 1-in-10-summer scenario.

"The California ISO is working with the industry to prepare for high electricity demand driven by heavy use of air conditioners. Last summer, California set seven new records for peak demand under normal temperatures," said ISO Interim Chief Operating Officer Jim Detmers. "Demand for electricity is growing at about 4 percent a year and it is likely we will break new records this summer. We believe supplies, under normal conditions, are adequate for this summer. We want to analyze a variety of conditions and that is why this exercise is important."

Over the course of three days, utilities and other energy companies that use the grid will submit simulated electricity schedules to the ISO as if it were a hot day in the middle of summer. Customers will feel no impact at all because "mock" schedules will be used detailing where energy will be produced, where it will be consumed and how the power will move over the grid. The ISO will run the schedules through a sophisticated computer model of the grid, which simulates how the power will actually flow.

The computers will simulate a typical summer day, a very hot heat wave and also throw in unexpected losses of key generating plants or transmission lines to see how sudden contingencies would affect the grid under various conditions. The simulation will be open to accept schedules for three days. However, conducting the simulation, performing the analysis and publishing results will take a couple of weeks.

The California ISO is a not-for-profit public benefit corporation charged with managing the flow of electricity along California's open-market wholesale power grid. The mission of the California ISO is to safeguard the reliable delivery of electricity, and ensure equal access to 26,000 circuit miles of "electron highway". As the impartial operator of the wholesale power grid in the state, the California ISO conducts a small portion of the bulk power markets. These markets are used to allocate space on the transmission lines, maintain operating reserves and match supply with demand in real time.