Hawai'i consumers hit the brakes on energy consumption last year as gasoline and electricity prices spiked to record heights.

The Monthly Energy Trend report issued by the state shows drivers bought 5.9 percent less gasoline in 2008 compared with 2007, while dimming use of electricity.

"Certainly, people changed their behaviors because of cost," said Ted Peck, administrator of the state Energy Office, remarking on the run up in prices last year. That was followed by declines late in 2008.

"Now they're changing their behaviors because of an economic downturn."

The report is further proof that last year's speculative surge in crude oil prices affected consumer behavior. Motorists cut back on trips after experiencing gas-pump sticker shock with a gallon of regular shooting above $4 in Honolulu in May and staying at those levels until early October.

At the same time, Hawai'i electricity prices spiked because most of it comes from generators fueled by fuel oil or diesel. Hawai'i is the most oil-dependent state in the nation.

"When people on the Mainland see it at the pump, we see it at the plug, at the pallet," said Peck, who is helping craft ways for the state to meet a goal of getting 70 percent of its energy from renewable energy sources by 2030.

"We have a challenge to make sure we continue to think long-term."

Residents on some islands paid more than 40 cents per kilowatt-hour at one point during the year.

On O'ahu, homeowners' rates peaked at 32.5 cents in September.

The new figures from the state show a general decline last year in use of anything related to the cost of crude, which swelled above $100-a-barrel during the first half of 2008. The downturn in the state's economy also damped activity as tourism fell and unemployment rose.

The report produced by the state Department of Business, Economic Development and Tourism shows Hawai'i's imports of foreign oil tumbled by one-tenth compared with 2007, with only 41.4 million barrels being imported.

Other figures show:

• Gasoline consumption fell to 440.9 million gallons as people drove less or switched to more fuel efficient vehicles.

• The number of gasoline-powered passenger cars at the end of the year (938,424) was almost 9 percent less than a year earlier.

• Total electricity sales statewide slumped by 1.8 percent compared with 2007, even though the number of customers rose. On O'ahu, there was a 1.6 percent drop in overall electricity consumption. Maui island's and Kaua'i's usage were down 3.1 percent, while the Big Island's power consumption slid 1.9 percent.

• Residential electricity sales fell 3.6 percent while commercial customers used 1.1 percent less.

• The number of electric passenger vehicles in the state grew by 10 to 171.

• The amount of aviation fuel sold fell by almost one-sixth, reflecting the demise of Aloha and ATA airlines and fewer flights.

• In December, both gasoline and electricity sales were lower than 2007 levels as prices came down from record levels reached earlier in the year.