The Federal Energy Regulatory Commission (FERC) issued on Thursday a proposal to standardize the definition of transmission facilities subject to mandatory reliability standards. The commission’s intent is to protect the reliability of the nation’s bulk power system.

The Notice of Proposed Rulemaking (NOPR) directs the North American Electric Reliability Corp. (NERC) to include all electric transmission facilities of 100 kV or more in its definition of what constitutes the "bulk electric system" subject to mandatory reliability standards under the Energy Policy Act of 2005. NERC is the commission-certified national electric reliability organization.

The proposal generally conforms to the current definition of the bulk electric system recognized by NERC and seven of the eight regional reliability entities around the country. It would eliminate the discretion that regional entities have to define the transmission facilities that constitute their "bulk electric systems" but allow regional councils to seek NERC and FERC approval if they wish to make variations from the 100-kV standard.

"Consumers and the economy depend on smooth operation of a reliable bulk power grid with consistent standards from coast to coast and from cities to rural areas," FERC Chairman Jon Wellinghoff said on Thursday. "But without this step, FERC cannot fulfill Congress’ intent to protect the bulk electric system."

The commission also notes there is a strong technical justification for a standard 100-kV threshold: Facilities rated at 115 kV and 138 kV have either caused or contributed to significant bulk electric system disturbances and cascading outages. The Feb. 26, 2008, Florida blackout originated from a fault at a facility connected to the 138-kV transmission system and resulted in the loss of 24 transmission lines and 4,300 MW of generation associated with 13 power plants and disrupted electric service to more than 3 million customers for several hours.

Comments on the NOPR (FERC Docket No. RM09-18-000) are due by about May 3, 2010.

Source: FERC