UPDATE: All Customers restored after System Event Interrupts Service for some Island Customers

Earlier this afternoon, there was an interruption to about 16,000 of Island customers, or 31 MW (5%) of supply, with most being restored within 7 minutes.

This was an “Under frequency load shedding event”, which occurred after a trip of the Labrador Island Link and switching event at the Soldiers Pond Terminal Station. Trips are designed to protect the system from further equipment issues, but in the process, customers can be disconnected from the electricity grid for a brief time. Hydro manages the system with reserve electricity supply available, which allows us to restore customers quickly during these events, as was the case today.

These “Under frequency load shedding events” occur occasionally in our power system because hydroelectric generators are very slow to respond following a disturbance. While there is plenty of generation available, the shedding of customers is sometimes needed to ensure the power system remains balanced following a disturbance.

Learn more about these types of events: https://nlhydro.com/good-to-know/what-is-underfrequency-load-shedding/

The investigation into today’s event is ongoing.