(BIVN) – Hawaiian Electric is again asking customers on Hawaiʻi island to limit their use of electricity this evening.

The utility says the “unavailability of several large generators” is prompting another reduction request – especially from 5 p.m. to 9 p.m. – in order to prevent the need for rolling outages.

“Last night, conservation efforts by households, businesses and government agencies helped ensure there was sufficient power to meet the evening peak demand,” a Friday news release from the power utility stated. “Hawaiian Electric thanks businesses for their help and asks the public to continue to patronize stores and restaurants tonight – they’ll still be open.”

Hawaiian Electric’s Hill 5 unit, which unexpectedly tripped offline yesterday, was returned to service last night, the company says. However, combustion turbine units, Kanoelehua CT-1 and Puna CT-3, “which normally supply about 32 megawatts of power, are offline with mechanical issues.”

At the same time, two units at the Keahole Power Plant, which usually supply about 36 megawatts of power, are undergoing annual scheduled maintenance.

Wind resources are forecast to be lower than usual, the utility says.