The court refused Thursday to reconsider its February ruling, despite requests from the power company, regulators and some business groups.
That leaves standing an order to the Public Service Commission to reverse an 18 percent rate increase and refund $337 million that’s been collected from 186,000 customers since 2013. The Thursday order instructs the commission to make refunds immediately.
The court found the increase illegal because regulators didn’t conduct hearings to ensure Mississippi Power was spending prudently on the $6.2 billion Kemper plant. It also ruled regulators used an illegal rate structure, didn’t notify all ratepayers and broke public meetings law by negotiating a deal in private.