Sometime you win, sometimes you lose.

On Monday, the state Public Utilities Commission approved Hawaiian Electric Co.'s request to raise electrical rates on O'ahu by 4.96 percent, or $70 million.

Yesterday, the PUC issued a revised order to a separate rate case calling for HECO to return $15 million to the utility's 293,000 residential customers.

The refund translates into a one-time, $17 refund for the typical residential customer, according to an HECO estimate.

HECO said the exact refund and its timing is still subject to a final decision by the PUC.

"The decision, when finalized, could result in an estimated refund to O'ahu customers of $15 million," the company said in a news release.

In a proposed final order yesterday, the PUC scaled back a 3.3 percent interim rate increase that the state agency issued in September 2005. The interim rate increase resulted in $41 million in revenues a year.

The PUC now says that the electric company should get a 2.7 percent rate increase, which is about $34 million a year.

HECO had been collecting the higher amount since 2005 and now must refund the difference.

The refund comes after the PUC on Monday granted HECO a 4.96 percent interim increase on a 2007 rate request. A final order on the 2007 case is pending.

According to HECO, the PUC wound up with a lower rate after it decided to exclude a large segment in the utility's rate base: the company's pension assets.

HECO added that other factors in its rate base, including operating expenses, capital investments and other electrical systems costs were upheld by the PUC.

"The difference between the earlier higher interim rate increase and the proposed final amount is solely due to the PUC's reversal of its decision on the ratemaking accounting treatment for the company's prepaid pension asset," HECO said.

WHAT RATE HIKE PAID FOR

The company said its 2005 case largely paid for new capital projects and service reliability projects. They included: