Thousands of Hawaiian Electric customers in Central and West Oahu were at risk of losing power Thursday night.

The company issued an island-wide request to turn off air conditioners and lights shortly before 5 p.m. or risk losing power. 

“What we asked customers to do is to conserve as much as possible, turn off air conditioners, use fans rather than air conditioners, not to cook during peak hours (5 to 8 p.m.), and not to use washer or dryers,” said Shannon Tangonan, Hawaiian Electric spokeswoman. 

Hawaiian Electric got close to turning off power to nearly six-thousand customers in areas like Waipahu, Kunia, Ewa Beach, Pearl City and Makakilo for one hour. 

And customers listened. HECO saying they saw a drop in usage shortly after the request was made. 

“Because of their conservation efforts, and because of one of the units coming back online, we were able to escape through without having to turn off any electricity,” Tangonan said. 

HECO says there’s more than 20 generating units across Oahu, and the conservation request came when four weren’t at full capacity.

HECO was doing scheduled maintenance on three generating units Thursday, when a fourth unit, Campbell Industrial Park, briefly stopped working. HECO says the weather didn’t help either. 

“On top of that there was low winds, so we didn’t get any wind generation and the weather itself, high humidity, was causing folks to use air conditioning and so on. So what we had was more demand than output of our generators and output needs to match demand,” Tangonan said. 

The last time HECO was forced to shut off the power was in January 2015, affecting customers in East Oahu and Mililani, Pearl City and Waipahu for several hours.

So how does HECO decide who loses power?

“We try not to shut off power with a lot of critical care facilities, hospitals, dialysis locations,” Tangonan said. “We try not to affect more people than we need to do.”

Campbell Industrial Park was the generator that did come back online during the peak, which helped power stay on for thousands of customers.