Electricity bills keep going up for residential customers on Oahu.

The bill in July for a typical household using 600 kilowatt-hours a month went up from June by more than a dollar to $217.24, according to data released Monday by Hawaiian Electric Cos., the state’s largest utility provider with service to Oahu, Maui and Hawaii island.

In the past two months alone, the typical Oahu bill has risen $6.96.

Hawaiian Electric Cos. spokes­man Peter Rosegg said this month’s bills are higher because of additional money earmarked for the public benefits fund that oversees the energy efficiency programs, rebates and other things that Hawaii Energy operates. Two percent of a customer’s bill is collected each month for this purpose.

"This is a percentage of each bill that Hawaiian Electric Cos. collect by order of the Hawaii Public Utilities Commission and pass in total to Hawaii Energy," Rosegg said. "Once a year there is (an adjustment) to make sure the proper total amount has been collected (for the previous 12 months)."

On Oahu the July rate rose to 34.7 cents a kilowatt-hour from 34.5 cents a kilowatt-hour in June when the typical bill was $216.08.

Last month bills also jumped on Oahu. That was primarily because of an annual rate adjustment called a "sales decoupling tariff" designed to compensate HECO for increased capital expenditures and declines in sales over the past year. Higher fuel prices also contributed to the June increase.

Decoupling, which began in 2011, is structured to encourage the development of renewable energy and energy conservation by eliminating the economic incentive on the part of the utility to sell more electricity. Decoupling, or breaking the link between sales and total electric revenue, essentially guarantees utilities enough revenue to cover their fixed costs even if their electricity sales decline.

Hawaiian Electric Co., its sister utilities in Hawaii and Maui counties, and the Kauai Island Utility Cooperative adjust their rates monthly to reflect changes in their fuel costs and the prices they pay for electricity purchased from independent power producers.

Maui Electric Co. customers this month are paying 37.8 cents a kilowatt- hour, up from 37.6 cents last month. The bill for a household using 600 kilowatt-hours of electricity is $235.28, up from $234.15 in June.

Hawaii Electric Light Co.’s residential rate on Hawaii island rose to 41.5 cents a kilowatt-hour from 40.0 cents a kilowatt-hour in June. The bill for a household using 600 kilowatt-hours of electricity is $259.42, up from $255.62.

Hawaiian Electric Cos. has more than 450,000 residential and commercial customers, with 300,000 on Oahu, 70,000 on Maui and 80,000 on Hawaii island.

On Kauai, meanwhile, the rate this month is 42.0 cents a kilowatt-hour compared with 42.2 cents in June. The bill for a household using 600 kilowatt-hours of electricity is $252, down from $253.20.

Average monthly kilowatt-hour usage varies by island, but the 600 kwh number is used for comparative purposes.

The price of electricity in Hawaii is more than three times the national average in large part because of the high cost of fuel oil used for power generation.

Hawaii residents paid an average of 38.1 cents a kilowatt-hour for electricity in April compared with the national average of 12.3 cents a kilowatt-hour, according to the latest data available from the U.S. Energy Information Administration.

The Hawaii Clean Energy Initiative, adopted by the state in 2008, set a goal that 40 percent of the state’s electricity will be generated from renewable resources by 2030.

At the end of 2013, 18 percent of Hawaiian Electric’s sales were made using renewable sources, surpassing the company’s goal of 15 percent for 2014, HECO said.

By the end of 2015, KIUC will be close to meeting its goal of using renewable resources to generate 50 percent of the island’s electricity, KIUC President and Chief Executive Officer David Bissell said last week at the 12th annual meeting of cooperative members.

Bissell said the cooperative will soon begin receiving power from its 12-megawatt solar array near the old Koloa Mill, and in 2015 KIUC’s 12-megawatt solar array will come online. Those two arrays will provide nearly half of the electricity consumed on Kauai during the daylight hours. KIUC also is developing plans for a 25-megawatt pumped storage hydropower project on the west side that could store some of the energy created during the day and use it at night when demand hits its peak.

KIUC board chairman Allan Smith said the cooperative’s strategic plan seeks to lower the average bill by at least 10 percent over the next 10 years.

"Our cooperative had one of its most productive years in 2013, and we’re well on our way to achieving the goal of using renewable resources to meet at least half of Kauai’s energy needs by 2023," Smith said. "We believe we will hit the target well ahead of schedule, so we’re already working on ideas for the other 50 percent."

KIUC, a member-owned cooperative that serves 33,000 customers, said a month after its rollout that nearly 700 customers are using the cooperative’s new MyMeter website, which uses the smart meter to enable customers to go online to track their energy use and not consumption trends.