Non-Consequential Load Loss

The planned use of Non-Consequential Load Loss (NCLL) by NB Power

NB Power operates in New Brunswick in conformance with mandatory reliability standards as regulated by the New Brunswick Energy and Utilities board (NBEUB). One such standard NBEUB standard, TPL-001-4 Transmission System Planning Performance Requirements, governs the circumstances under which NB Power may utilize Non-Consequential Load Loss (NCLL) in its efforts to protect the New Brunswick bulk electricity system during certain significant system disturbances.

For NB Power, use of NCLL takes the form of continued use of Under Voltage Load Shedding (UVLS) for the specific cases identified in its 2021 Planning Assessment Report. UVLS devices detect localized low voltages and quickly shut off the power to associated power lines to minimize potential equipment damage that may result from operating at low voltages.

The 2021 Planning Assessment addresses planned uses of NCLL in the following areas of the province:

At the Manawagonish Road substation in the Saint John area. Estimated frequency of planned NCLL occurrence is 0.000056 events/year, or once every 17,900 years.
At the Pennfield and Milltown terminals affecting the St. George, Deer Island, Campobello, Grand Manan, and southeastern Maine (only customers of Eastern Maine Electric Cooperative) areas. Estimated frequency of planned NCLL occurrence is 0.0116 events/yr, or once every 86 years.

NB Power has publicly engaged customers and stakeholders who are potentially affected by the use of Non-Consequential Load Loss (NCLL) as outlined reliability standard TPL-001-4. At the information session, representatives from NB Power presented an overview of the 2021 Planning Assessment Report and responded to questions or concerns raised by participants.

The Planning Assessment Report and other resources contained on this website, including questions from the public and responses, will be filed with the New Brunswick Energy and Utilities Board (NBEUB) in the coming months for approval of continued use of NCLL in New Brunswick.

Non-Consequential Load Loss (NCLL) dispute resolution procedure