Suppliers deny the accusation.
Generators engaged in market manipulation and consistent patterns of bidding far above costs in the deregulated energy market, the California Independent System Operator found in a study of pricing data. We think the entire amount deserves consideration for refunds. The study concluded that energy suppliers commonly offered their electricity at twice their cost. Cal-ISO's public filing will quantify the alleged overcharging by each company, but the companies will be identified only by a number. Perkins also bitterly disputed charges that Reliant has shut down units so that it can earn bigger profits on the power sold by the remaining plants.