Hawaiian Electric on Monday again asked customers to conserve power to avoid the need for additional rolling outages after more than 21,000 customers lost power Sunday.
HECO initiated several 30-minute outages Sunday between 8:54 p.m. and 9:59 p.m., impacting 21,557 customers, after the provider’s Hill 5 steam unit unexpectedly tripped offline Saturday.
HECO spokeswoman Kristen Okinaka said those outages took place all over the island.
The Hill 5 unit is only one of several units that currently are offline, which collectively generate a maximum of roughly 122 megawatts.
HECO’s Puna steam unit and CT-1 combustion turbine are under repair, and its Keahole CT-1 unit is on the mainland undergoing an annual overhaul until the end of April. Those three generators and the Hill 5 unit together can contribute up to 62 megawatts to the grid.
Meanwhile, Hamakua Energy, HECO’s largest independent power producer, also is offline, reducing the grid’s capacity by another 60 megawatts.
Okinaka said Sunday’s outages were the first to be implemented since HECO on March 25 called for customers to conserve power after Hamakua Energy first went dark. She said HECO has been lucky since then, with abundant wind power available to cover the shortfall. However, Sunday was the first time there was not enough wind to generate sufficient power.
Although HECO did not implement any further outages Monday morning, Okinaka said temporary outages could be executed to prevent a greater loss of power until the offline generators are restored. The scope and duration of such outages will be determined based on the amount of electricity demand that needs to be reduced.
However, Okinaka said there is no estimate for when any of the troublesome generators will be fixed, save for the Keahole CT-1 unit. The scheduled overhaul for that generator should be completed by the end of April.
Customers are therefore advised to reduce energy consumption, particularly during the hours of peak demand between 5 p.m. and 9 p.m.
Conservation and rolling outage alerts and updates will be posted on the company’s social media accounts on Facebook and X (formerly Twitter). Okinaka also urged customers to subscribe to alerts from Hawaii County Civil Defense through its Everbridge emergency notification system and through its traditional emergency warning channels, including local radio.
Email Michael Brestovansky at mbrestovansky@hawaiitribune-herald.com.