A report released by the agency tasked with managing and operating the state’s power grid found that Diablo Canyon nuclear power plant isn’t essential to keeping California’s electricity flowing, prompting county officials to begin envisioning a future without the plant’s economic and energy-related benefits.

On Feb. 1, the California Independent System Operator (CAISO) released its 2012-13 Transmission Plan, an evaluation of the state’s transmission grid that identifies upgrades needed to meet policy goals, and examines the grid’s reliability requirements and projects that could benefit consumers.

One section of the report studied nuclear generation backup plans. In it, the CAISO assessed the state grid’s reliability in the absence of Diablo Canyon and determined there were “no material mid- or long-term transmission system impacts” associated with the plant’s absence.

“The absence of [Diablo Canyon] appears not to have negative impact on the reliability of the ISO transmission system with the assumption that renewable generation resources would develop according to the CPUC portfolios,” the report reads.

In other words, the CAISO found that sans a Diablo Canyon nuclear power plant, the electricity grid won’t collapse, and the lights won’t go out.

The study noted, however, that resource requirements such as planning reserve criteria and future resource needs would require further study.

Specifically, they need to address the prospect that Diablo Canyon—which is currently embroiled in the renewal process for its two reactors’ operating licenses—may not be around forever due to natural events or changes in policy or regulation regarding plant functions, such as once-through cooling.

The only other plant in the state, the San Onofre Nuclear Generating Station (SONGS) in Southern California, has been offline since January 2012 due to problems with tubes in its steam generators, and its fate remains uncertain.

The CAISO report became the focus of a discussion of long-term planning goals at the Feb. 19 San Luis Obispo County Board of Supervisors meeting, prompted by a comment from David Weisman, outreach coordinator for the Alliance for Nuclear Responsibility, a ratepayer advocacy group.

“What would happen if Diablo Canyon was no longer able to provide that revenue to schools and social services?” Weisman asked the board during public comment. “While the impossible and improbable is happening with greater frequency, will San Luis Obispo County be caught?”

The question caught board members off guard and prompted a discussion about planning how the county would manage financially without the plant.

“I, for one, wasn’t even aware of this report,” said Supervisor Bruce Gibson.

County Chief Administrative Officer Dan Buckshi said the county would likely have to contract out for that kind of information, but noted that, offhand, the loss of revenue from Pacific Gas & Electric in taxes alone “certainly wouldn’t be pleasant.”

Though revenues from the plant equate to only about 1 percent of the county general fund, Buckshi said, the San Luis Coastal Unified School District relies on property taxes from Diablo Canyon for roughly two-thirds of its annual budget.

The board also noted that the plant employs hundreds of residents, and a closure would surely send ripples through the local economy.