Starting this month, Central Maine Power Co. customers are paying an average of $15.56 more a month – a 12.6% increase – for storm cleanup, renewable power, and incentives for electric heat pumps and electric vehicles.

The increase is not as high as it could have been because some costs have gone down, including for transmission. The overall cost increase is calculated as the amount paid by ratepayers who use an average of 550 kilowatt-hours a month. The changes bring the average CMP customer’s total bill to $138.76.

The higher rates were approved in separate cases by the Maine Public Utilities Commission in recent weeks, but to a large extent, the increased charges reflect public policy set by the Legislature.

PUC Chairman Philip L. Bartlett said at a recent meeting of the agency that state tax policy is a better tool than electricity rates to collect revenue for funding public policy goals such as renewable energy payments to meet Maine’s climate goals.

“With any rate design change, some customers will benefit while others are adversely impacted,” he said. “Trying to collect public policy costs in electric delivery rates is inherently challenging and conflicts with traditional cost-of-service ratemaking principles.”

Ideally, tax policy and tapping the state’s general revenue would provide “equitable considerations,” Bartlett said.

“Recovering those costs through rates will almost always be less equitable,” he said.

CMP serves most of Maine, with 653,170 customers in western, central and southern parts of the state.

Those customers will be billed about $5 more to pay an additional $179.3 million for various policies, including the pass-through costs for net energy billing, which credits solar developers and other generators for renewable power they produce and send to the electric grid. This also includes purchase agreements, required by the Legislature, for power generated by wind and solar farms, as well as maintenance of unused CMP assets, such as the shuttered Maine Yankee Nuclear Power Plant in Wiscasset.

The largest share of the increased rate – more than $10 for the average customer – is to reimburse CMP $220 million for cleanup following destructive storms in 2022 and 2023.

And about $1.50 is for increased electric conservation programs, particularly expanded heat pump subsidies, promoted by Efficiency Maine Trust, a quasi-state agency. Its $60.3 million budget is up from $50.7 million last year, Executive Director Michael Stoddard said. Unspent money helped reduce the amount sought by utilities, he said.

Some customers of the state’s second-largest utility, Versant Power, will pay less starting this month. Versant serves 165,000 businesses and residents in northern Maine.

A residential customer in the Bangor Hydro District – Hancock, Piscataquis and Washington counties and most of Penobscot County – using 550 kWh a month will pay $1.83 less on a $149.91 bill for delivery and standard offer supply, the default cost of electricity.

However, a residential customer using 550 kWh in the Maine Public District, which includes Aroostook County and a small part of Penobscot County, will pay $6.99 more on a $137.35 bill.

Unlike CMP, which recently received state approval for higher rates to pay for storm restoration, Versant is seeking permission from the PUC to increase rates next year. Versant is looking to collect $171.8 million in revenue to fill a $34.1 million gap for storm cleanup and projects that include replacing transformers and installing covered wire.

For customers, rates will increase by $12 a month, up nearly 25% if regulators approve the request.