Electricity bills for households on Maui and the Big Island are expected to drop significantly in April, while falling just slightly on Oahu, based on the effective rates this month.

The typical Oahu bill (for a household using an average of 600 kilowatt-hours of electricity) should be at $117.94, just 0.6 percent less, or 77 cents lower, than it was in March.

For Maui, however, the typical bill amounts to $140.13 in April, a 4.8 percent drop and $7.17 less than it was in March.

On the Big Island, the typical bill for a household should come out to about $184 in April, which is $11.96 less, or 6.1 percent lower than it was in March.

The effective rates, which include fuel and other charges, for April were at 18.23 cents/kwh on Oahu, 22.01 cents/kwh on Maui and 28.82 cents/kwh on the Big Island.

HECO spokesman Peter Rosegg said the electricity bills recorded for April are the lowest for Oahu since the summer of 2007. The rates have been on a steady decline since November of last year.

Rates vary on different isles because of different sources of fuel and different storage capacities. Maui uses mostly diesel while the Big Island uses mostly medium sulfur fuel oil. On Oahu, HECO uses mostly low sulfur fuel oil. Lower oil prices - at a little more than $50 per barrel for West Texas Intermediate, for example - are a contributing factor.