INDIANAPOLIS - The Indiana Court of Appeals yesterday struck down approval of Vectren’s plan to spend roughly $90 million in ratepayer money on its aging A.B. Brown and F.B. Culley coal-fired power plants outside Evansville. The Court found that the Indiana Utility Regulatory Commission violated the law by failing to determine whether Vectren met all legal requirements before approving Vectren’s use of the new equipment. The Court’s decision means that the case goes back to the Commission to decide whether Vectren should be allowed to pass the costs of the projects on to its ratepayers.