The utility gets state approval to initiate a tiered rate structure for residential customers

Hawaiian Electric Co. has introduced a tiered rate structure for its residential customers on Oahu that increases the cost of electricity per kilowatt-hour as usage goes up.

The new system brings Oahu into line with what HECO launched in January at its subsidiaries on Maui, the Big Island, Molokai and Lanai.

HECO said the changes on Oahu that went into effect yesterday coincide with a decision by the state Public Utilities Commission last Friday to implement the final pieces of a 2009 rate hike sought by the utility.