The Supreme Court has rejected arguments that California customers were overcharged for electricity sold by the Bonneville Power Administration in parts of Utah and other areas of the West.

The California Public Utilities Commission said California customers were forced to pay a share of BPA costs spent solely for the benefit of customers in its primary marketing area - parts of Utah, Washington, Oregon, Idaho, Montana west of the Continental Divide, and parts of Utah, Wyoming and Nevada within the Columbia River drainage area.The court, without comment Monday, let stand a ruling that said California customers properly were required to pay a fair share of the power agency's costs.

The Bonneville Power Administration is an arm of the U.S. Department of Energy. It sells power from 30 federal dams and two nuclear power plants known collectively as the Columbia River Power System.

In the appeal acted on Wednesday, the California agency sought refunds from the BPA of more than $100 million for the period July 1981 to October 1983.

The California agency also said customers there should not be required to help pay the costs BPA incurred on abandoned Washington Public Power Supply System nuclear plants.

The 9th U.S. Circuit Court of Appeals ruled against the California agency and customers that included the Aluminum Company of America, Arco Metals Co., the Los Angeles Department of Water and Power, Pacific Gas and Electric Co., San Diego Gas & Electric Co. and Southern California Edison Co.

Only the state agency appealed to the high court.

The 9th Circuit court substantially upheld a ruling by the Federal Energy Regulatory Commission in BPA's favor.

The appeals court noted that FERC "observed that even if California purchasers have unequal access to BPA power, and subsequently claim it has less value to them, that fact does not affect what it costs BPA to produce the energy."

Moreover, the appeals court said, it was legal and appropriate for BPA to try and recover some of the financing for the abandoned WPPSS nuclear plants by spreading the costs as widely as possible among BPA customers.

The appeals court also said California customers have benefited from cheap power purchased from BPA. During the disputed period, California customers saved about $1.5 billion while BPA was suffering losses of more than $680 million, the appeals court said.

The case is California Public Utilities Commission vs. FERC and BPA, 90-505.