Residential electric rates on Oahu rose to a record high in August, reflecting rising fuel costs and an interim rate hike that Hawaiian Electric Co. began collecting late last month.

A typical household using 600 kilowatt hours of electricity a month saw its bill rise to $205.44 in August from $199.68 in July, HECO said. The August rate of 32.8 cents a kilowatt hour was up from 31.9 cents a kilowatt hour in July and surpassed the previous high of 32.5 cents reached in September 2008 in the wake of record oil prices.

The increase from July to August was in large part due to an interim rate hike that HECO began collecting on July 26 that added $3.31 a month to the typical bill on Oahu. The rate hike is to pay for capital improvement projects. The rest of the increase was primarily fuel-related, HECO said.

With three-fourths of Hawaii’s electricity generation coming from petroleum-fired power plants the state is extremely vulnerable to volatility in crude prices. Hawaii has the highest electricity rates in the nation by far. The average cost per kilowatt hour nationwide was 11.2 cents in February, according to the U.S. Energy Information Administration. Hawaii’s average was 31.04 cents in February. The next highest was Connecticut at 17.63 cents.

One group that has not complained about Hawaii’s high electricity prices are the installers of solar photovoltaic systems and their customers.

"My electric bill has been zero since February," said Duane Preble, a retired University of Hawaii professor who has about 40 photovoltaic panels installed on the roof of his Manoa home.

"I totally expected this and it’s going to get worse," he said of the rising electricity prices. Preble uses his solar panels to power his home and charge his Nissan Leaf electric car.

"Not only am I able to pass by gas stations and have a zero electric bill, I’m not contributing to troubles in Middle East."

For its part, HECO said it is working to incorporate more renewable sources into its energy portfolio to blunt the impact of rising oil prices.

"The cost for fuel is a huge 61 percent of the bill on Oahu," said HECO spokesman Peter Rosegg. "As you know, we take no profit or markup on fuel. That is a direct pass through.

"This illustrates how important it is to add as much fixed-price renewable energy and fixed-cost renewable fuel on Oahu as possible so we can stabilize and eventually shrink that portion of the bill," Rosegg said.

Rising electricity prices are a top concern of the Blue Planet Foundation, a Honolulu-based nonprofit working to establish Hawaii as a leader in energy independence.

"We’re convinced that a clean energy future will be the most affordable path for both residents and businesses," said Jeff Mikulina, executive director. "The quicker we can transition, the better."

Mikulina said one major hurdle that needs to be cleared is setting up a better system to finance alternative energy projects. The Legislature took a major step in that direction last session, ordering the Public Utilities Commission to study the implementation of an "on-bill financing" mechanism that would allow utility customers to divert a portion of their bill to pay for things such as solar water hearing systems and photovoltaic projects, Mikulina said.

While residential electricity rates rose on Oahu in August, they fell on the neighbor islands.

Maui Electric Co. customers saw rates fall to 36.6 cents per kilowatt hour this month from July’s 37.1 cents. The typical Maui bill fell to $227.36 from $230.06.

Hawaii island residential rates fell to 41.7 cents per kilowatt hour from last month’s 41.8. The typical bill fell by 51 cents to $261.73.

On Kauai the rate fell to 41.7 cents per kilowatt hour. Last month the rate charged by the Kauai Island Utility Cooperative was 42.9 cents per kilowatt hour.