KAILUA-KONA — Hawaii Electric Light Co. reports that customers in various areas of Hawaii Island experienced a power interruption Thursday night.
An estimated 24,000 customers (about 28 percent) experienced a power interruption at 7:43 p.m. when generating units at HELCO’s and Keahole Plant tripped offline unexpectedly. Automated load shedding operated properly while alternate generation was started. Service to most customers was restored within 12 minutes and the remaining customers were restored by 8:24 p.m.
“We sincerely apologize for the power interruptions and thank the community for their patience and understanding,” said Hawaii Electric Light spokeswoman Kristen Okinaka. “We’re currently investigating the cause of the trips but we do know that the cause was not due to a lack of sufficient generation.”
When generation supply or demand changes very quickly, protective devices automatically disconnect loads to help maintain service for the majority of customers. This is called Under Frequency Load Shedding and is necessary to protect the island’s power grid. Some customers will experience a temporary power interruption while backup generators are started.