Hawaiian Electric Co.’s bills continue to decline with oil prices as Oahu customers are set to see roughly a $4 discount in March from February.

The bill for a typical household using 500 kilowatt-hours on Oahu will be $123.06 this month, $4.41 less than what customers paid in February. The price per kilowatt-hour on Oahu decreased to 22.6 cents this month from 23.4 cents in February. The March price is the lowest in more than six years, HECO spokesman Darren Pai said Monday.

“Our customers are continuing to receive the savings from low oil prices,” Pai said. “But for the long term, continuing to rely on oil is a bad bet, and that’s why we are committed to transitioning to low-cost renewable energy to reach our state’s energy goals and ensure sustainable savings for our customers.”

The last time HECO’s customers on Oahu saw a bill this low was when it was $122.34 in January 2010.

Despite the tumbling price, Hawaii still has the highest electrical rates in the nation, due in part to the state’s use of imported oil for most of its power.

Hawaii’s price of electricity is more than double the national average, according to the latest figures from the U.S. Energy Information Administration. Hawaii’s residents paid an average of 26.86 cents a kilowatt-hour in December, while the national average was 12.36 cents in the same month.

In 2014 oil made up roughly 71.3 percent of the energy mix of HECO and its subsidiaries on Maui and Hawaii island. HECO imports oil mainly from Southeast Asia and the Middle East. Other states use natural gas, hydro­electric power, coal or nuclear power, which keeps costs low.

Unlike others in HECO’s service territory, Maui Electric Co. customers will see an increase in rates to 25.9 cents per kilowatt-hour from 24.6 cents in February. A household using 500 kilowatt-hours will pay $139.17, up from $132.58 last month.

Pai said electrical bills on Maui are slightly higher in March because the contracted price for wind energy is higher than the cost of using oil to generate electricity, and Maui Electric is expected to use more wind energy in March.

A Maui residential customer is still paying $44.68 less than in January 2015, the month fuel prices were highest in 2015, and $76.11 less than in September 2008, when fuel prices were at an all-time high, according to HECO.

Bills for customers on Hawaii island are the lowest in nine years.

The residential rate for Hawaii Electric Light Co. customers on the Big Island was 28.5 cents a kilowatt-hour, down from the 29.8 cents a kilowatt-hour residents paid in February, when the average bill was $160.87. The March bill for a household using 500 kilowatt-hours of electricity is $154.26.

The Kauai Island Utility Cooperative dropped its rate to 28.7 cents a kilowatt-hour in March from 29.3 cents a kilowatt-hour in February. The bill for a household using 500 kilowatt-hours of electricity, including a $10.58 customer base charge, is $154.08, down from $157.08.

Like Oahu, customers on Molokai and Lanai also are seeing the lowest monthly electrical bills in more than six years.

Maui Electric Co. customers on Molokai using 400 kilowatt-hours of electricity will pay an average of $122.61 with effective rates of 28.2 cents a kilowatt-hour, down from 29.6 cents a kilowatt-hour in February, when the typical bill was $128.13. Customers on Lanai using 400 kilowatt-hours of electricity will pay 28.6 cents a kilowatt-hour, down from 30.2 cents a kilowatt-hour in February. Lanai residents will pay $124.12 in March compared with $130.51 in February.

The typical customer bill on Lanai and Molokai is measured with electrical use at 400 kilowatt-hours due to lower energy use, HECO said.

Monthly bills include the cost for kilowatt-hours used plus other charges.