How does net metering work in Maine?

Maine’s Net Energy Billing program — often called net metering — gives homeowners a one-for-one credit for each kilowatt-hour (kWh) their solar system sends to the grid. Credits roll over month to month for up to 12 months and help offset future CMP bills.

How do CMP solar credits appear on my bill?

CMP compares how much power you used from the grid with how much your solar system sent back. If you exported more than you used, you’ll see those kilowatt-hour credits listed on your bill, which reduces your future supply charges.

Do net metering credits expire?

Yes. In Maine, credits can be used for up to 12 months on a rolling basis (what you use in June must be used by the following June). After that, any unused credits expire.

Does net metering eliminate my entire electric bill in Maine?

Not completely. In Maine, you’ll still pay CMP’s fixed monthly delivery charge — around $27 — which covers your connection to the grid. Net metering offsets your usage costs, not that flat service fee.

Can I track my solar production myself?

Yes! You can easily track your solar production and CMP net-metering credits with your system’s monitoring app (such as SolarEdge). The app shows how much electricity your panels produce each day and how much power flows to the grid. Comparing that data with your CMP bill helps confirm that your credits and generation totals match. At Maine Solar Solutions, we review this data with every customer after installation. That way, you know how to read your information and verify your system’s performance.

Is net metering available everywhere in Maine?

Yes. Net energy billing (net metering) is available to most residential customers of both Versant Power and Central Maine Power under Maine’s statewide program.

Can net metering in Maine change in the future?

The Maine Public Utilities Commission (PUC) periodically reviews Maine’s net metering policy , but most proposed updates focus on larger commercial systems. Maine’s Net Energy Billing program remains open and has not changed for new residential participants. Homeowners who install solar under today’s terms stay on those terms for the duration of their agreement (typically up to 20 years), even if the program changes for future residential installations.

Net Metering in Maine: How It Works, CMP Credits & Solar Savings

Updated November 2025

What Is Net Metering in Maine?

If you’ve been exploring solar, you’ve likely come across Maine’s Net Energy Billing policy — or net metering. It’s one of the key programs that helps make solar energy practical and affordable in Maine. It lets homeowners share extra power with the grid and earn credits.

In most of Maine, Central Maine Power (CMP) manages net metering — tracking every kilowatt-hour your home sends to and draws from the grid. That’s how you earn and use the credits that lower your electric bill each month.

Before we get into how billing and credits work, it helps to picture how your solar system and CMP’s grid work together day-to-day.

How Your Solar System Interacts with CMP’s Grid

Your solar panels capture sunlight and turn it into electricity that powers your home. During the day, your home uses that solar power first. When your panels make more than you need, the extra electricity flows out to the grid — and you earn net metering credits for it. The diagram below shows how your home solar system connects to the grid. It traces the flow of power from panels to the inverter, service panel, and meter.

Diagram showing how Maine’s net metering policy credits homeowners for excess solar power sent to CMP’s grid.

At night or during the winter, when your panels produce less or no power, you draw electricity from the grid and use your stored credits to cover your usage.

That exchange between your system and the grid is what keeps solar energy seamless — letting you use your own energy first and bank the rest for later.

In short, Maine’s net metering policy tracks that give-and-take. It measures how much electricity your home sends out and how much it pulls back in. The result is what appears as credits and usage on your CMP bill each month.

So how does that tracking actually show up on your bill? Let’s take a closer look.

How CMP Net Metering Credits Show Up on Your Bill

Your CMP bill shows a record of how your solar system and the grid traded electricity over the month — how much power you sent out, how much you drew in, and the balance between the two.

For each kilowatt-hour (kWh) your system exports to the grid, CMP gives you a one-for-one credit. You can use those credits to offset future electricity use.

Each billing cycle, CMP compares those totals:

If your system sent out more electricity than you used, the extra becomes credits on your account.
If you used more than you produced, CMP applies your banked credits first, then bills you for the remainder.

How credits appear on your bill

Your bill can look confusing at first, but once you know what to look for, it’s straightforward. The sample below shows how CMP lists your energy usage, solar generation, and credits.

CMP solar bill example showing net metering credits and solar generation in Maine.

How Credits Roll Over Each Month

Credits carry forward on a rolling 12-month basis — meaning any credits earned in a given month must be used within that same month the following year. For example, credits earned in June need to be used by the following June. After that, any unused credits expire and can’t be used.

That’s why we don’t recommend oversizing your system. It should closely match your household’s annual electricity use. Our solar consultants design and size each system carefully to match your energy needs and maximize your savings — without leaving credits unused. And if your usage grows later (say, after adding an EV charger or heat pumps), your system can be expanded to keep pace.

In Maine, solar production naturally rises in summer and dips in winter. Those sunny months help build the credits that carry you through the darker, colder ones. During high-production periods, many homeowners see their kWh cost drop close to zero.

The CMP Fixed Delivery Fee

You’ll still see CMP’s fixed delivery charge — about $27 per month as of 2025 for solar customers — which covers your grid connection. Net metering offsets your energy supply costs, but not that flat monthly fee.

How to Track Your Solar Production and CMP Credits

So how can you tell what your system is producing beyond what shows up on your CMP bill?

Your CMP bill tracks how much power you import from and export to the grid, but it doesn’t show your system’s total production. That’s where your solar monitoring app — like SolarEdge — comes in.

Your monitoring app gives you real-time insight into how much energy your solar panels are generating. Comparing that data to your CMP bill gives you the full picture:

How much of your solar power your home used directly
How much went back to the grid to earn credits
And whether CMP’s generation numbers align with your own system’s data

Think of your CMP bill as your energy statement and your monitoring app as your performance dashboard.

Checking both each month helps you stay confident your system is performing as expected — and spot any changes in production quickly.

Using Solar Credits Across Properties in Maine

Maine’s virtual net metering policy lets you apply solar credits from one CMP account to another account under the same customer name.

Some homeowners choose to slightly oversize the system on their primary home so the extra credits generated in summer can offset usage at a camp, rental, or other property. For example, a homeowner in Brunswick might use extra credits from their main home to offset their Harpswell cottage account.

It’s a simple, smart way to make the most of your solar investment and extend the benefits of clean, local power beyond a single property.

Can Maine’s Net Metering Policy Change?

It’s a fair question — and one we hear often.

Net metering has been part of Maine’s energy policy for more than a decade and is overseen by the Maine Public Utilities Commission (PUC). You can view the full program details on the Maine PUC’s Net Energy Billing page.

While the program is periodically reviewed, most of the recent updates in the news — including 2025 legislative changes — primarily affect larger commercial and community-scale projects, not typical residential rooftop systems.

Maine’s Net Energy Billing program remains open and unchanged to new residential participants. Homeowners who install solar under today’s terms stay on those terms for the duration of their agreement (typically up to 20 years), even if the program changes for future residential installations.

That’s one reason many Mainers are choosing to go solar now: it locks in today’s crediting structure and protects the long-term value of the energy your home produces.

How Batteries Work with Net Metering in Maine

Adding battery backup makes your solar system even more flexible. Grid-tied systems automatically shut down during a power outage for safety, but with a battery, your home can stay powered using stored solar energy.

Because Maine’s 1-to-1 net metering already provides full credit for energy you export, we typically configure batteries in grid-tied systems as a backup power source — so you keep earning credits while having reliable power ready when the grid goes down. Unlike some states, Maine doesn’t use time-of-use rates, so your credits hold equal value day or night.

Batteries don’t replace net metering — they complement it, giving you more control, independence, and peace of mind.

Why Net Metering Matters for Maine Homeowners

Net metering is what makes solar practical — and financially worthwhile — in Maine’s seasonal climate. It lets you turn summer sunshine into winter savings. That balance helps keep your energy costs predictable year-round.

Locking in Long-Term Savings

It also helps protect you from rising electricity rates. With CMP proposing rate increases over the next five years, locking in your energy savings now enables you to avoid those future costs.

Net metering isn’t just good for your wallet — it’s good for Maine. Every kilowatt-hour your system produces is one less pulled from fossil fuels, helping our state move toward a cleaner, more self-reliant energy future.

The bottom line: Net metering remains the foundation that makes solar work financially in Maine. It rewards you for producing clean, local power and ensures you get full value for every kilowatt-hour your panels generate.

The policy is strong — and homeowners who go solar now can lock in their benefits under today’s rules.

Ready to See How Solar Could Work for You?

At Maine Solar Solutions, we’ve helped thousands of Mainers understand their solar options and design systems that maximize long-term savings.

Our team guides you through every step — from local permitting and utility coordination to final net-energy-billing enrollment — so your system is installed, approved, and earning credits as smoothly as possible.

Together, we’ll design a solar solution that fits your home, your budget, and your energy goals.
Schedule your free, no-pressure consultation with our Maine-based team today and see how net metering can help you save.