CMP and APS Rate Hikes: Maine and Arizona Push Back

In September 2025, two major utilities asked regulators for large rate increases. In Maine, Central Maine Power proposed a five-year plan that would add more than $400 a year to the average household bill. In Arizona, Arizona Public Service sought a 14% increase, its fourth in a decade.

Both faced sharp pushback from state leaders. The outcomes since then show how regulators are responding to affordability pressure.

Here is what each utility asked for, what happened next, and what it means for how the grid gets paid for.

What Did Central Maine Power Ask For?

Central Maine Power proposed a five-year rate plan that would raise revenue by more than $430 million and increase the average customer's bill by about $36 a month, or more than $400 a year, according to News From The States.

CMP said the plan would build a "smarter, stronger, more resilient grid," reduce storm-related costs, and support the clean energy transition.

Governor Janet Mills called the request "massive and unacceptable," saying it "blatantly ignores the economic reality that Maine people face every day." Public Advocate Heather Sanborn called it "an enormous increase."

What Happened to CMP's Rate Plan?

On November 18, 2025, the Maine Public Utilities Commission unanimously dismissed CMP's five-year rate plan, the first time the commission had entirely rejected a distribution rate case, according to Maine Public.

The commission's reasons included:

• ●Affordability. Customers couldn't absorb increases at the proposed pace.
• ●Planning law. The plan didn't align with state requirements for long-term grid proposals.
• ●Public opposition. More than 800 public comments opposed it.
• ●Cost control. The multi-year structure wouldn't encourage cost discipline.

Commissioner Patrick Scully said "our people simply can't afford to do so at the pace proposed here." CMP can file a new traditional rate case or request a temporary increase while it develops its required grid plan.

What Did Arizona Public Service Ask For?

Arizona Public Service requested a 14% rate increase, about $579.5 million, following increases of 8% in 2024, 8% in 2023, and 4.5% in 2017, according to Utility Dive.

APS said rising demand requires upgrades including substations, smart grid technology, vegetation management, battery storage, and security improvements. It noted transformer costs have risen 64% since its current rates were set.

Attorney General Kris Mayes opposed the request. She said Arizonans "deserve a power system that is reliable, equitable and resilient — but not one where a monopoly utility profits on the backs of struggling families."

Why Is Arizona Fighting Over Formula Rates?

APS also asked to use "formula rates," which would let it adjust charges annually with less of the review that comes with a full rate case.

The Arizona Corporation Commission voted 3-2 in late 2024 to allow formula rate plans, according to KJZZ. Mayes has opposed them, warning: "It leads to abuses, and it leads to fewer checks and balances on the utilities."

The APS rate case hearing ran from May to July 2026. The commission expects a recommended decision by late November 2026 and must vote by December 31, 2026, with new rates expected in early 2027, according to the ACC.

The question isn't whether the grid needs investment. It's who pays, how much, and how fast.

Why Are Utilities Asking for So Much?

Utilities say they need more money for grid upgrades, storm resilience, and new technology, driven by rising demand from data centers, electrification, and severe weather.

Those needs are real, and nobody disputes that the grid needs work. Equipment costs have climbed, extreme weather is more frequent, and demand is growing after years of being flat.

But the requests land on customers already stretched by rising costs. We covered the national picture in why electricity bills are rising faster than inflation and the $186 billion question of who benefits from grid spending.

Are Regulators Pushing Back Elsewhere?

Yes. Regulators in several states have cut utility requests sharply.

In New York, regulators cut Con Edison's first-year electric request by 87% and approved a smaller National Grid increase than the utility sought.

The pattern is clear. Affordability is now a central factor in rate decisions, not an afterthought, and public comments are shaping outcomes.

How Can Customers Protect Themselves From Rate Increases?

Customers can reduce exposure to rising rates by producing their own power, storing it for peak hours, and cutting waste.

Options include:

• ●On-site solar. Offsets energy purchased from the grid.
• ●Battery storage. Cuts peak demand charges and adds backup power.
• ●Efficiency upgrades. Lower use reduces the impact of every increase.
• ●Existing solar at full output. Making sure installed systems are actually producing.

What Does This Mean for Existing Solar Owners?

Every rate increase makes a working solar system more valuable, because each kilowatt-hour it produces offsets more expensive grid power.

Many commercial systems installed in the 2010s are losing output to aging inverters or degraded panels. Repowering an aging PV system restores that output using the site and connection already in place.

Start With a Ballpark Estimate

Rate pressure isn't going away. Find out what your existing solar project may be worth before deciding whether to repair, repower, or sell.

Sources: News From The States, "Gov. Mills opposes CMP plan"; Maine Public, "Maine PUC dismisses controversial CMP rate plan"; Utility Dive, "Arizona attorney general opposes APS' proposed 14% rate hike"; KJZZ, "Arizona regulators defend decision to let utilities seek annual rate increases"; Arizona Corporation Commission, "What's Next in the APS Rate Case?"