Why storage is not an arbitrage play in Maine
In states that pay a fraction of retail for exports, a battery earns its keep by converting cheap exports into expensive self-consumption. Georgia, Utah and Tennessee all work that way.
Maine does not. Net Energy Billing credits exported kilowatt hours against usage one for one at the retail rate, so a kilowatt hour exported and a kilowatt hour consumed are worth the same.
That removes the main economic argument for storage. A battery here does not increase the value of your generation, it only changes when you use it.
There is a marginal benefit: storage keeps generation inside your own consumption rather than accumulating credit that could be eliminated at the end of the rolling 12-month window. But that only matters for a system already producing an annual surplus, which is a sizing problem rather than a storage solution.
The resilience case, specified properly
Coastal and southern Maine take winter storms that bring the power down, sometimes for days. That is a legitimate reason to buy storage and it should be evaluated on its own terms rather than dressed up as savings.
Solar alone will not help. A standard grid-tied inverter disconnects when the grid goes down, for the safety of line workers, so an array without a battery and the right switching arrangement is inert during an outage.
Ask precisely which circuits would be backed up and for how long under a realistic winter load, including whatever your heating system needs to run. The answer should be a list of circuits, not a reassurance.
Ask what happens after the first day. A multi-day December outage with short days and possible snow cover on the array is the scenario that matters here, and a battery sized for an evening is a different product from one meant to ride out a storm.
The Efficiency Maine payment worth asking about
Efficiency Maine operates a Small Battery Incentive Program that pays battery storage owners for participating in demand response events on the New England grid.
Those events typically occur 40 to 60 times between June 1 and September 30, so the payment is concentrated in summer rather than spread across the year.
Ask your installer whether the battery being proposed is eligible and enrolled, what the payment structure is, and what participation requires of you.
Ask also how programme participation interacts with holding charge in reserve for outages. Those two objectives pull against each other, and you should be the one deciding how they are balanced.
Costing it out under the current tariff
The 30 percent federal Residential Clean Energy Credit under Section 25D expired for property placed in service after December 31, 2025, so a cash or loan purchase receives no federal tax credit on either the panels or the battery, and Maine has no state solar tax credit or rebate.
Section 48E survives at 30 percent for third-party owners under leases and power purchase agreements, so ask what a provider claims and what reaches you in the rate.
What exists is one-to-one Net Energy Billing at the retail rate, the property tax exemption under 36 M.R.S. Section 655 which covers batteries storing solar electricity, and the Efficiency Maine Small Battery Incentive.
Ask for the system priced and modelled with and without storage, so the incremental cost of the battery is a visible number, and price the resilience as a thing you are choosing to buy rather than folding it into a savings figure.