|A utility substation near Treasureton in southeast Idaho.|
Periodic activity on the Sun's surface sends powerful waves of energetic particles toward the Earth. These solar events can distort the Earth's magnetic field, affecting the flow of electricity on Earth. While serious geomagnetic disturbances are expected to be infrequent, they can cause blackouts and damage key utility infrastructure.
The Federal Energy Regulatory Commission has jurisdiction over the reliability of the U.S.'s bulk electric power system. To this end, it has designated the North American Electric Reliability Corporation (NERC) as the nation's electric reliability organization. In May 2013, FERC directed NERC to develop and submit new standards for protecting the grid against geomagnetic disturbances (Order No. 779).
FERC and NERC have proceeded in a two-stage process. First, in June 2014 FERC approved a standard on implementation of operating plans, procedures and processes to mitigate effects of geomagnetic disturbances (Order No. 797).
Reserved for the second stage were further requirements that transmission planners and owners assess the vulnerability of their systems to a theoretical benchmark event. NERC subsequently proposed such a standard, calling for an evaluation of what would happen in a “one-in-100-year” benchmark event.
In a Notice of Proposed Rulemaking issued today, the FERC proposes to largely adopt NERC’s proposed second-stage standard. The standard would require covered entities to have system models needed to complete vulnerability assessments, to have criteria for acceptable steady state voltage performance during a benchmark event, and to complete a vulnerability assessment once every 60 calendar months. If the assessment indicates that a system does not meet the performance requirements, the entity would have to develop a corrective action plan addressing how the requirements will be met.
The proposed rulemaking would direct NERC to further modify its standard to require that the study and benchmarking of geomagnetic disturbance events is based on a more complete set of data and a reasonable scientific and engineering approach.
Comments on today’s Notice of Proposed Rulemaking are due 60 days after its publication in the Federal Register.
Geomagnetic disturbances, and their impacts to the grid, are a hot topic in energy regulation at the present. States are considering laws regulating utility readiness for and response to geomagnetic disturbances; for example, next week the Maine Legislature’s Joint Standing Committee on Energy, Utilities, and Technology will consider LD 1363, An Act To Secure the Maine Electrical Grid from Long-term Blackouts.