Power Facts
Power Delivery
How Electricity Gets to You
- Hawaiian Electric's 138,000-volt (138-kV) transmission lines transport bulk electricity to transmission substations.
- These substations reduce the power to 46-kV.
- Then 46-kV lines go to local area distribution substations, which further step down the voltage to 12-kV or 4-kV.
- These lower-voltage distribution lines are further stepped down to 240 volts or 120 volts and connect to businesses and homes.
Electricity Travels Through Corridors, Like Highways, From Power Plants to Customers
Electricity travels through a network or grid of transmission and distribution lines from power plants and substations to customers.
On Oahu, most of the power is generated by plants located on the west side of the island. Electricity is delivered throughout the island through two primary transmission corridors-one in the north and the other in the south.
The northern and southern corridors function like highways. If an emergency occurs in one, electricity can still reach customers through the other highway.
Transmission System "Redundancy" for More Reliability
In addition, major subtransmission systems are also built for "redundancy." More than one circuit usually serves larger areas so if one line goes out of service for maintenance or emergencies, the electricity path can be switched to an alternate route to serve customers.
24-Hour Trouble Crews Keep the Lights on for Customers
Hawaiian Electric field crews work 24 hours a day, seven days a week to make sure service is restored safely, rapidly and efficiently for all customers
Undergrounding Utility Lines
Hawaiian Electric owns and operates operates more than 9,800 miles of transmission and distribution lines across the five islands we serve. Underground powerlines are commonly deployed in Hawaii. Approximately 43% of these lines are already underground, demonstrating a significant investment in underground infrastructure to ensure reliability and minimize visual impacts.
