20160504press release.pdf

Case No. PAC-E-15-10, Order No. 33519
Contact: Gene Fadness [phone], 890-2712
www.puc.idaho.gov

Commission accepts Rocky Mountain curtailment plan

BOISE (May 4, 2016) – State regulators are approving an updated Rocky Mountain Power plan
spelling out the steps the utility would take to curtail energy consumption during energy supply
emergencies.

The plan, last updated in 1993, is outdated by advances in technology, changes in industry
practice and the utility’s generation capacity. Further, the 1993 plan addresses only long-term
shortages and not the more typical short-term events. The updated plan addresses the more
common short-term emergencies such as a temporary loss of generation, failed equipment,
extreme weather and temperatures or a system disturbance within the Western
Interconnection.
The Idaho Public Utilities Commission said Rocky Mountain Power’s plan contains “appropriate
procedures” to temporarily interrupt electric service to customers during emergencies and
power shortages while, at the same time, minimizing adverse impacts to customers and
maintaining system reliability.
Rocky Mountain Power, a division of PacifiCorp, serves customers in Utah, southeastern Idaho
and much of Wyoming.
The plan states that the company will endeavor to contact the commission before outages.
“Such reporting is significant because the commission is the designated Energy Emergencies
Coordinator for response and recovery efforts dealing with significant disruptions in energy
supplies for all hazardous emergency situations,” the commission said.
The plan recognizes that the utility already has demand-side management (DSM) programs
under which customers reduce load during peak consumption during periods of short supply
and it has large customers that already agree to be interrupted to achieve reductions in load.
The plan anticipates five stages that are used as the energy deficit increases.
The first stage is to implement load shedding from customers that can be contractually
interrupted or are part of the company’s existing DSM program. The second stage is a public
appeal to voluntary load reduction by all customers. Third is a mandatory up to two-hour
curtailment during peak hours by customers who have been grouped into blocks of about 100
megawatts near selected distribution feeders. However, distribution feeders serving facilities
essential to the public welfare are avoided during this rotational curtailment. These include,
among others, hospitals, 911 centers, airports, large water and sewer treatment plants, prisons,
police and fire stations and facilities critical to electric system operation. The commission said it
expected Rocky Mountain “to take serious its commitment to identify and avoid curtailment of
circuits that serve essential services.”
The fourth step is a mandatory curtailment in two-hour block rotations during peak or non-
peak hours. The fifth and final step is mandatory emergency load reduction.
Under the former plan, only the State of Idaho could declare an energy emergency that would
trigger curtailment. The updated plan recognizes the role of the Western Electricity
Coordinating Council (WECC) and its Regional Reliability Coordinator to implement and enforce
regional reliability standards in the western United States. Emergencies that threaten the
integrity of the electric system can develop at any time due to a shortage of generation or
disturbances on the system, either locally or within the Western Interconnection. Thus, the
updated plan states that WECC or the Idaho Commission may order energy curtailments.
However, nothing precludes Rocky Mountain Power from requesting voluntary load reduction
at any time.
The plan eliminates financial penalties that could be assessed parties for noncompliance with
curtailment orders.
“We encourage and look forward to more frequent updates by all utilities regarding their
curtailment plans,” the commission said.
The company’s plan and other documents related to the case are available on the commission’s
website at www.puc.idaho.gov. Click on “Open Cases” under the “Electric” heading and scroll
down to Case No. PAC-E-15-10.

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