The Ohio Supreme Court ruled in favor of the Public Utilities Commission of Ohio in a $42 million decision.
The PUCO had ordered AEP to return as much as $42 million in profit from the 2009 year.
PUCO officials called that money excessive profits at the time.
On Thursday, the Supreme Court ruled PUCO was right in their decision.
PUCO officials said that AEP refunded some of that money to customers already, through small reductions in their bill for much of 2011.
An AEP spokesperson told 10TV the remaining money will be invested in a renewable energy program.
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