PORTLAND, Maine (AP)   The agency that represents the interests of Maine utility customers is skeptical of a costly proposal to improve the state’s power grid in the face of increasingly intense storms.

Public advocate Barry Hobbins says he wants more details of the plan, and assurances that ratepayers won’t be on the hook for the costs.

Avangrid is the parent company of Central Maine Power. It’s proposing a $2.5-billion, 10-year effort in Maine and New York to improve system reliability during storms, upgrade infrastructure and more. At least some of the costs would fall on ratepayers under the proposal.

Utility spokeswoman Gail Rice said details aren’t yet sorted out and that regulators will have the final say.

Hobbins said the advocacy group worries the power company has “old ideas.”