The typical home, which uses about 600 kilowatt hours, will see their bill drop about 7.4 percent to $182.01 from the $196.52 they were billed in October.
HECO says more cuts could be in order given oil's decline. Most of the electrical generators in Hawaii run on oil.
That should provide some relief for homeowners who have seen their bills rise this year to a peak of 32.5 cents per kilowatt-hour in September. It now stands at 28.9 cents.
Hawaii residents have the highest average statewide electricity rates in the nation, paying almost three times the U.S. average.