West Maui customers were told last Wednesday that Hawaiian Electric might have had to cut power as a fire prevention measure under the new protocols of the utility's Public Safety Power Shutoff program, which launched in July.
Here’s how it works: HECO looks at weather data on wind gusts and humidity. When wind speeds are higher than 45 mph and humidity is lower than 45%, the utility considers de-energizing its power lines.
"When you have high winds and low humidity, then there's the risk that a tree could fall and knock down a power line. And there could be very dry grass or trees nearby," said HECO spokesperson Darren Pai.
That combination of downed power lines and dry vegetation can spark a fire, which is what caused the deadly blaze that destroyed Lahaina, according to a recent report from the Bureau of Alcohol, Tobacco, Firearms and Explosives.
HECO's shut-off program is supposed to help ensure that never happens again. Pai said Wednesday was the closest the utility has come to shutting off power under the new program.
"We were essentially within 1 mph of wind gusts to the point where we would need to de-energize the certain circuits in West Maui," he said.
However, using data from the National Weather Service and the utility's growing network of weather stations, HECO ultimately decided not to take that step.
The utility has been working to build out its weather and fire monitoring system. It expects to have a total of 52 weather stations installed by the end of the year. It's also installing 100 AI-powered cameras around the islands that will help detect wildfires.
Pai said these measures, along with the shut-off program, are key to the utility's fire prevention strategy moving forward.
