By Michael Brooks and Rich Heidorn Jr.

WASHINGTON — FERC on Thursday approved a NERC reliability standard requiring grid operators to assess and protect against the threat of geomagnetic disturbances (RM15-11).

The final rule (Order 830), effective 60 days after its publication in the Federal Register, is nearly identical to the commission’s proposed rulemaking issued in May last year. Under the rule, certain transmission owners and planners will be required to assess the vulnerability of their systems to a “benchmark” GMD event, defined as a one-in-100-year occurrence. They would then need to submit plans to mitigate the identified vulnerabilities. (See Questions and Answers on NERC’s Proposed GMD Rules.)

NERC will also need to submit a work plan within six months of the rule’s effective date detailing how it will study GMD events in general, “given the limited historical geomagnetic data and because scientific understanding of such disturbances is still evolving,” FERC said.

“While we recognize that scientific and operational research regarding GMD is ongoing, we believe that the potential threat to the Bulk Electric System warrants commission action at this time, including efforts to conduct critical GMD research,” the commission said.

GMDs, caused by solar events that disrupt the planet’s magnetic sphere, are considered “high-impact, low-frequency” events.

Response to Comments

FERC’s original Notice of Proposed Rulemaking questioned certain aspects of NERC’s proposed standard, TPL-007-1, including its reliance solely on spatial averaging to calculate the size of the impacted area in the benchmark event.

In comments submitted in response to the NOPR, NERC and other industry stakeholders defended the standard’s methodology for the benchmark definition, but FERC said they did not provide any new information.

“NERC and industry comments largely focused on the NOPR’s discussion of one possible example to address the directive” to modify the calculation so that it did not rely solely on spatially averaged data, FERC said. “However, while the method discussed in the NOPR is one possible option, the NOPR did not propose to direct NERC to develop revisions based on that option or any specific option.”

The commission gave NERC 18 months to make those revisions, as well as to modify the standard to require that data from geomagnetically induced current monitors and magnetometers be made public and to establish specific deadlines for mitigation plans.

In a few cases, FERC declined to direct NERC to make revisions it had considered in the NOPR, instead including them as part of NERC’s study homework.

For example, the commission had questioned whether the benchmark definition should also be modified to reflect that GMDs could have pronounced effects on lower geomagnetic latitudes. While it said that commenters who defended the original calculations did not provide any new information, the commission declined to direct NERC to revise the latitude scaling factor, saying it found “sufficient evidence to conclude that lower geomagnetic latitudes are, to some degree, less susceptible to the effects of GMD events.”

The final rule represents the second stage of the commission’s effort to protect against GMD, an effort that began in May 2013 with Order 779. The first stage, approved in June 2014, dealt with developing operating procedures for responding to GMDs and mitigating their effects.

Data Lacking

Commissioner Cheryl LaFleur called last week’s order “a milestone reflecting over five years of work by the commission, our staff, NERC, industry and stakeholders to address the threats posed” to the grid by GMDs. “It’s not the beginning of the end but the end of the beginning. We still have a lot of work to do.”

LaFleur said the rule “appropriately balances the need for action on this important issue with a recognition that our understanding of the science around GMD events and their operational impacts on the grid is still evolving.”

“One of the things we found frustrating in our tech conferences in developing the final rule was that so much of the magnetometer and monitoring data was from Canada or Europe when in fact we have one of the most highly developed electric grids in the world and very little public data on which to base our analysis.”

Situational Awareness Requirements

The commission also gave final approval to reliability standards IRO-018-1 and TOP-010-1, which specify requirements for the real-time reliability monitoring and analysis capabilities of reliability coordinators, balancing authorities and transmission operators (RD16-6).

The standards implement Order 693, which specified operators’ minimum capabilities, as well as the recommendations contained in a 2008 NERC best practices report and the joint FERC-NERC report on the 2011 Arizona-Southern California outage.

FERC noted that inadequate situational awareness was identified as one of the key causes of the 2003 Northeast blackout.

The joint report on the Arizona-Southern California outage recommended that entities “should take measures to ensure their real-time tools are adequate, operational and run frequently enough to provide their operators the situational awareness necessary to identify and plan for contingencies and reliably operate their systems.”

NERC said the new standards build on existing requirements by requiring applicable entities to provide them with indications of the quality of information being provided by their monitoring and analysis capabilities and notify them of real-time monitoring alarm failures.

Frequency Control Standards

The commission also gave preliminary approval to NERC’s proposed standard BAL-005-1 (Balancing Authority Control) and FAC-001-3 (Facility Interconnection Requirements), which it said would clarify and consolidate existing frequency control requirements (RM16-13).

The commission said the proposed standards “support more accurate and comprehensive calculation of reporting area control error (ACE) by requiring timely reporting of an inability to calculate reporting ACE and by requiring balancing authorities to maintain minimum levels of annual availability of 99.5% for each balancing authority’s system for calculating reporting ACE.”

The NOPR also seeks the retirement of standards FAC-001-2 (Facility Interconnection Requirements) and BAL-006-2 (Inadvertent Interchange).

The commission said it was uncertain whether to support NERC’s proposal to also retire requirement 15 of standard BAL-005-0.2b (Automatic Generation Control), which requires the maintenance and periodic testing of backup power supplies at primary control centers and other critical locations. “Depending on the explanation received in comments, the commission may issue a directive in the final rule to restore the substance of requirement R15 in the reliability standards,” it said.