Iberdrola must open its books as CMP seeks greater profits in ongoing rate case, Maine utility regulator says

MAINE MONITOR • August 5, 2026

The proceedings over Central Maine Power’s latest request for a rate increase have taken another unprecedented turn. On Wednesday, the Maine Public Utilities Commission asked the electric utility to hand over internal documents from its multinational parent company, Iberdrola, which could offer insight into how the company estimates how much it needs to earn to cover expenses and appease investors. “This appears to be the first time that any multinational corporation in the U.S. has been forced in a rate case to divulge its own internal math,” said Seth Berry, who leads Our Power, a nonprofit that advocates for affordable clean energy in Maine. The electric utility has asked the Maine Public Utilities Commission for permission to raise distribution rates for customers. The PUC already rejected a request by CMP in 2025 to raise distribution rates.