Graphic courtesy Hawaiian Electric

(BIVN) – Hawaiian Electric is again asking Hawaiʻi Island customers to reduce their use of electricity from 5 to 9 p.m. tonight. The utility says it may not have enough firm generating capacity available to meet the evening peak demand.

“The need to conserve is urgent tonight and is prompted by the unavailability of three major generators,” stated a Hawaiian Electric news release issued on Thursday afternoon.

“Hawaiian Electric’s Hill 5 unit unexpectedly tripped offline this afternoon and two units at the Keahole Power Plant are undergoing annual scheduled maintenance. These units usually supply about 50 megawatts of power,” the utility said. “In addition, wind resources are forecast to be low.”

The Big Island faced a similar situation in late August, when Hamakua Energy Partners, the largest independent power producer on the island, was shutdown due to the unavailability of ammonia used for pollution control. At the same time, Hawaiian Electric’s Hill Plant Unit No. 5 and Puna Steam Plant also are unavailable due to planned annual maintenance and repairs. In that instance, the call to conserve energy lasted last than a week. “Thousands of households as well as small and large commercial customers who reduced their use of electricity helped prevent the need for rolling outages,” Hawaiian Electric said.

Today, along with asking customers to conserve power, Hawaiian Electric is taking these steps:

• Asking large commercial customers, including hotels and resorts, to voluntarily reduce energy use, especially heavy equipment and air conditioning
• Placing maintenance personnel on standby to address unexpected issues
• Requesting maximum output available from Puna Geothermal Venture

“By reducing demand, Hawaiian Electric can ensure enough electricity is available and prevent the need to initiate rolling, 30-minute outages,” the utility said. “If rolling outages are necessary, Hawaiian Electric will make every effort to use social media to notify customers in the affected areas in advance. Please check @HIElectricLight  on Twitter for updates.”