Oahu residents will see a slight increase in their September electric bills due to higher fuel prices.

Customers’ bills will be up $1.82, or 1.2 percent, this month after August bills dropped $3.70 from July.

The increase is due to higher oil prices, according to Hawaiian Electric Co., the state’s largest utility provider with service to Oahu, Maui and Hawaii island.

“Typical residential bills increased slightly on Oahu in September due to higher fuel costs,” said Darren Pai, HECO spokesman.

The bill for a typical household using 500 kilowatt-hours on Oahu is $144.33 this month, HECO said. The price per kilowatt-hour increased to 26.8 cents this month from 26.4 cents in August, when the average bill was $142.51.

Hawaii has the highest electrical rates in the nation due in part to the state’s dependence on imported oil for most of its power. In 2013, oil made up roughly 72 percent of the HECO companies’ energy mix. Other states use natural gas, hydro­electric power or nuclear power to keep costs low.

The latest figures provided by the U.S. Energy Information Administration show that Hawaii’s price of electricity is more than double the national average. Hawaii residents paid an average of 30.39 cents a kilowatt-hour in June. The national average was 12.93 cents in June.

As Oahu residents are set to pay higher bills because of fuel costs, neighbor island residents will see a decrease in September bills due to lower prices for their fuel mix.

“Typical bills were slightly lower on other islands due to slight reductions in their fuel costs,” Pai said. “We understand the impact of volatile and rising fuel prices on our customers, so we are committed to increasing our use of diverse renewable energy resources at lower and more stable prices.”

The generators on the neighbor islands use different types of fuel, according to Hawaiian Electric. Oahu predominantly uses low-sulfur fuel oil. Maui primarily uses diesel. Hawaii island uses a mix of diesel and other types of fuel.

“It’s like paying for gas at the pump,” Pai said. “Different prices for different types of fuel.”

The residential rate for Hawaii Electric Light Co. customers on Hawaii island decreased to 32.1 cents a kilowatt-hour from 32.4 cents in August, when the average bill was $174.16. The September bill for a household using 500 kilowatt-hours of electricity is $172.43.

Maui Electric Co. customers using 500 kilowatt-hours of electricity will see a decrease in rates to 29.4 cents per kilowatt-hour from 30.8 cents in August, when the average bill was $164.44. Maui customers will pay an average of $157.12 this month.

The Kauai Island Utility Cooperative lowered its rate to 31.13 cents a kilowatt-hour in September, from 32.2 cents a kilowatt-hour in August. The bill for a household using 500 kilowatt-hours of electricity, including a $10.58 customer base charge, is $166.23, down from $171.58.

Average monthly usage varies by island, but the 500-kilowatt-hour number is used to make comparisons. Monthly bills include the cost for kilowatt-hours used plus various other charges.

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

Maui Electric Co. customers on Molokai using 400 kilowatt-hours of electricity will pay an average of $149.59 with effective rates of 34.9 cents per kilowatt-hour, down from 35 cents per kilowatt-hour in August, when the typical bill was $149.83.

Customers on Lanai using 400 kilowatt-hours of electricity will pay 33.9 cents per kilowatt-hour, a decrease from the 35.9 cents per kilowatt-hour in August.

Lanai residents will pay $145.71 in September compared with $153.70 in August.

Price of Power

Electrical bills by island based on a typical household using 500 kilowatt-hours. Lanai and Molokai figures are based on 400 kilowatt-hours for a typical household.