California State of Emergency (October 27, 2019): Operation of Portable Back-up Generators to Alleviate the Threat to Public Health and Safety in Anticipation of an Imminent Public Safety Power Shutoff

Advisory #293

December 3, 2019

This advisory addresses the timing of use of portable backup generators in connection with a Public Safety Power Shutoff (PSPS) event. This advisory supplements the previously issued advisory regarding use of backup generators while power is disconnected as a result of a PSPS event.1 We recommend referring to both advisories in conjunction with the applicable regulations to understand the compliance requirements.

In limited circumstances as described below, portable generators may be operated during PSPS events prior to the inactivation of the distribution line servicing the generator site if necessary to alleviate threats to public health and safety.
Where unregistered and unpermitted portable generators are moved frequently between sites, following the submittal of a CARB Form 402 within 24 hours of commencing initial operation, an owner or operator may submit subsequent Form 40s to CARB to list the location(s) of the where the portable generator has operated, on a weekly basis.
Owners or operators must first check with their local air district to determine that the use of a portable generator to provide emergency back-up power is allowed at the site.

The current fire weather conditions in California pose an imminent threat to the health and safety of Californians, both through on-going wildfires and PSPS events that interrupt the electrical power available from utilities.3 CARB rules currently allow operation of portable back-up generators during PSPS events caused by extreme fire weather conditions in limited circumstances; however, operators wishing to use generators for this purpose must first check with their local air district to determine what local requirements may apply.

During PSPS events, commercial utility customers who have lost power may need to operate portable diesel-powered back-up generators to alleviate an immediate threat to public health and safety. Due to staffing and technology limitations during the emergency, some customers operating generators for public health and safety, such as for powering telecommunications equipment or other critical equipment, may be unable to automatically initiate operation of a backup generator at the moment the power is shut off, and may not have staffing onsite to operate the back-up generator. In these cases, equipment may lose power and crucial services could be interrupted if the backup generator is not operated in advance of the loss of power during the PSPS.

When conducting a PSPS event, California’s utilities send a first notification to customers two days in advance. 4 One day prior to the deactivation of the distribution line, the utilities send a second notification that the deactivation is imminent. Extreme fire weather conditions are present for the duration of the PSPS event including when the deactivation is imminent. Further, the exact timing of the deactivation of the distribution line servicing a specific site is unknown, thereby precluding reliance on utility power. Under such circumstances, CARB rules allow operation of back-up generators to alleviate threats to public health and safety.

For unpermitted and unregistered portable generators, CARB regulations allow operation of back-up generators provided that the operator submits a CARB Form 40 “Notification of Operation in an Emergency Event” to CARB within 24 hours of commencing operation. Some customers operating portable generators for public health and safety, such as to power telecommunications equipment, or other critical equipment during a PSPS event may need to move generators quickly and frequently between sites. In such events, the owner or operators should submit updated Form 40s to CARB for each location where the equipment is operated, on a weekly basis.

Users are also reminded that only federally-certified engines may be used to power portable generators, even under emergency conditions. They may only reside at a given location for less than 12 months under the portable engine requirements.

To take advantage of the elements of this advisory, a utility customer must first notify CARB in advance by sending an initial Form 40 to portable@arb.ca.gov, and a letter indicating the desire to take advantage of this advisory by describing how the customer’s equipment is necessary for public health and safety; why their equipment lacks an ability for automatic initiation once power is lost; and why personnel are not available on-site to trigger operation of the generator manually.

Upon request by the air district or CARB, the operator must demonstrate:
- The operator submitted the Form 40 and letter to CARB in advance to portable@arb.ca.gov, and
- The operator received notification that the PSPS event will occur within one day3 , (second notification from the utility), and
- The operation of the facility is necessary to alleviate threats to public health and safety, and
- The facility lacks necessary equipment to automatically initiate operation of a portable generator, and
- The facility is operated without staff on-site, and
- The portable generator initiated operation no more than 24 hours prior to the scheduled power shut off, and
- The portable generator ceases operation as soon as practically possible after the power is restored.

Following the submittal of a Form 40 within 24 hours of commencement of initial operation, Form 40 notifications for operation of unregistered portable generators at each site may be updated on a weekly basis by submitting forms to portable@arb.ca.gov.

Notwithstanding state requirements and this advisory, stationary back-up generators are often subject to local air district requirements. These requirements vary by air district, and they may include permitting, emissions limits, and operational restrictions. Owners and operators of stationary back-up generators must contact the air district in which the generator would be operated to ensure that such generators are operated in accordance with applicable district rules and requirements. Under certain conditions, a portable generator, operated at a stationary source, may be considered a stationary generator. Owners of small engines, at or below 19 kilowatts (kW), should check with their local district for any permitting requirements.

Operators must first check with their local air district to determine that the use of a portable generator to provide emergency back-up power is allowed at the site.