By Jason Fordney

FERC last week approved CAISO Tariff changes to establish a process for selecting and procuring black start resources needed to restore segments of California’s transmission system in the event of regional outages.

Black start refers to the ability of a generating unit to begin operating without assistance from the electric grid. Such units are needed to restart other generation and restore the grid after widespread outages; they have certain requirements under the ISO’s Tariff.

CAISO staff last year determined that additional black start capability was needed in the transmission-constrained San Francisco Bay Area, prompting staff to develop new procurement standards to be applied across the ISO. (See CAISO Board OKs Black Start, TAC Area, EIM Charter Measures.)

The changes reorganize and consolidate certain black start provisions, create rules for technical requirements and operating tests, and remove outdated provisions. They also designate the cost of incremental black start as a reliability cost and allocate it to the transmission owner in the area where the units are located (ER17-2237).

The new black start provisions entail significant involvement of the affected TO — in this case Pacific Gas and Electric — in drawing up technical specifications and vetting proposals from resources bidding into the solicitation. The ISO would have authority to accept or reject a TO’s recommended resources. PG&E supported the changes and cost allocation method.

Under the new rules, CAISO will use a cost-of-service approach to compensate selected resources, rather than provide a capacity-type payment sufficient to support the operation of an otherwise unprofitable generator.

FERC said the revisions improve the reliability and clarity of the Tariff.

“Because individual black start capacity resources do not benefit all parts of the system equally, it is just and reasonable to recover these costs from a participating transmission owner where the resource is located and serves the reliability need,” FERC said. No parties objected to the cost allocation, and the benefits were roughly commensurate with the costs, the commission said.

To comply with CAISO rules, black start generators must make a minimum number of starts, operate in standalone and parallel modes, be able to pick up load during start-up load, produce and absorb reactive power, and have communication and control equipment.