How to sell solar batteries: attach at the sale, or work the 3.3 million

In 2015, one residential solar permit in 800 mentioned a battery. In 2025 it was one in about three and a half. Nothing else in how American solar is sold has moved that far that fast, and most of the movement happened in two years — which means most solar reps learned to sell before the battery was part of the sale, and are now adding it on the way out the door.

This page is for those reps. It uses what the permit record says about when batteries actually get sold, explains the tariff change that made them sell, and lays out the two motions that follow from it — one that is working and one that mostly is not. The underlying figures are in solar battery attachment rates, with the methodology that makes them safe to quote; every level there is a floor and this page treats them as floors.

Disclosure: Scout Data is our product. The permit database the figures come from, and the list of solar homes without recorded storage it produces — by install year, state and owner — is what our homeowner files and Scout field app are built to deliver. The selling advice stands on its own.

Nothing here is tax, financial or electrical advice. Incentive rules changed in 2025 and continue to vary by state and utility; what a battery can back up depends on its size and the home’s loads. Confirm both on the proposal, not on the porch.

Two motions, and the permit record’s verdict on each

There are two ways a battery gets sold. Attached to a new solar system, in the same conversation, on the same permit — or retrofitted onto an array that is already on the roof. The permit record is unambiguous about which one happens.

Of 398,812 homes in Scout Data’s permit database that hold both a residential solar permit and a permit recording storage, 93.4% permitted the battery in the same year as the array. Only 20,420 homes in the entire country added storage to an existing system in a later year. Against 3,757,036 homes with a solar permit, that is a retrofit rate of 0.54%.

Read that as a rule for how to spend a rep’s time. The attach is the motion: it is where nine batteries in ten get sold, and the homeowner is already in a buying conversation with a proposal in front of them. The retrofit is a real but narrow motion, worked from a list, against a base rate under one percent — and it needs a different pitch, covered below, precisely because the homeowner already said no to storage once, or was never asked.

Why the attach happened: the export credit

The attach rate on residential solar permits ran from under 1% to about 8% between 2017 and 2023 — the era of the battery as a premium backup product for people who wanted it. Then it broke: 8.0% in 2023, 18.8% in 2024, 29.0% in 2025.

The break has a date. California replaced retail net metering with NEM 3.0 on April 15, 2023, cutting the credit for exported solar sharply. Under that tariff a system without a battery gives away most of what it makes at midday and buys electricity back at dusk, so storage stopped being a backup purchase and became part of the economics of the array. California is 40% of the residential solar permits in the database and moved the national line on its own — but with California removed entirely, the rate on legible permits still ran from 9.7% in 2023 to 22.5% in 2025. The states that watched California are following it, a year or two behind.

The state table confirms the mechanism. Hawaii, which closed retail net metering in 2015 and has the highest electricity prices in the country, reads 85.1%. California reads 50.2%. States that still offer full net metering sit at the bottom, though the bottom of that table is partly a paperwork artifact — New Jersey’s most common solar permit description is the single word “Solar.” The lesson for a rep is not the ranking. It is that the battery sells where the tariff makes it pay, and the tariff is a fact about this homeowner’s utility that the rep can look up before the appointment.

Selling the attach

The attach is sold inside the solar proposal, not after it, and the order matters: tariff first, backup second, never the reverse.

1. Start from the homeowner’s own bill and their utility’s export rate. What the utility pays for a kilowatt-hour sent out at noon, and what it charges for one bought back at seven in the evening. Where those numbers are far apart, the battery is the device that keeps the noon kilowatt-hour for the evening, and the arithmetic is the pitch. Where they are close — full net metering — say so, and do not manufacture savings that the tariff does not produce.
2. Then backup, honestly sized. A home battery runs selected circuits for a period that depends on its capacity and what is on those circuits. “Keep the fridge, the lights and the internet running through an outage” is a true and useful sentence; “power your whole house indefinitely” is not, and it is the sentence that produces the complaint after the first long outage.
3. Present the system with and without storage, and recommend one. Two proposals, same roof, with the tariff math on each. The homeowner is buying this system once; the retrofit rate says that if the battery is not in this conversation it is probably never in any.
4. Say the “once” out loud. Not as pressure — as a fact about the market. Adding storage later means a second permit, a second crew, and often inverter work that the original install would have avoided. Fewer than one solar home in a hundred and eighty has done it.

The rep who does this well is not selling a battery. They are showing the homeowner what their own tariff does to a system without one, and letting the arithmetic make the recommendation.

The retrofit motion: 3.3 million arrays

Roughly 3.3 million American homes have a solar array and no recorded battery, most of them installed under a net-metering regime that is being withdrawn state by state. That is the retrofit market, and it is large, sceptical and mostly unworked. Selling into it is a targeting problem first and a pitch problem second.

The list that makes the base rate tolerable has three filters:

• Install vintage. An array from the Powerwall era was sold on a tariff that may no longer exist for its owner; an array from last year was sold with the battery conversation already had, and lost. The older the system, the more likely the tariff under it has changed since.
• Utility and tariff. Homes in a territory that has moved away from retail net metering, or whose utility has announced it will. This is the same mechanism that drove the attach curve, applied to systems that pre-date it.
• Outage exposure. Streets that lost power in the last year. Backup is the second reason to buy, and it is a much stronger second reason in a home that has recently sat in the dark.

Two further pools are worth their own lane. Homes whose original installer is no longer in business have nobody to call about anything, storage included; orphaned solar systems covers finding and working them. And any solar home is only a retrofit prospect if it actually has panels — permits are filed for systems that were never built, so the array is confirmed from the roof before the list is dialled; how to find homes with solar covers reconciling the two records.

The retrofit opener is not “would you like a battery.” It is a fact about this system: “your array went in around [year] — has your utility changed what it pays you for the power you send back since then?” Most owners of older systems do not know, and the honest offer is a look at the current bill against the current tariff, with the battery as the answer only if the arithmetic says so.

Incentives: say less than you know

For years the federal residential credit did a lot of the closing. Under the One Big Beautiful Bill Act, the section 25D residential clean energy credit does not apply to expenditures made after December 31, 2025 — and an expenditure is treated as made when the installation is complete, per the Congressional Research Service’s summary of the change. Homeowner-owned batteries installed now do not carry it. Third-party-owned systems fall under a different section of the code with its own phase-down; state and utility programmes exist in some places and not others, and change.

The rep’s line is therefore short: “there may be state or utility programmes that apply, and the proposal will show exactly what does.” A rep who quotes a credit that no longer exists has sold a battery that will be cancelled when the accountant looks at it.

The objections, and what is actually behind them

• “It’s too expensive.” Usually means the tariff math was not shown, or the house is on full net metering and the math is genuinely thin. Show the bill with and without; if the savings are not there, say so and sell backup or nothing.
• “I’ll wait for prices to come down.” A fair instinct. The honest reply is about the retrofit cost, not the battery cost: a second crew, a second permit, and possibly inverter work that the original install avoids. The homeowner can wait; the system they are buying today makes waiting more expensive.
• “My utility still pays me full rate.” Then the economic case is thin today, and the rep should say so rather than argue. Whether the tariff is scheduled to change is a checkable fact, and it is the only honest reason to add storage on economic grounds in a full-net-metering territory.
• “We never lose power.” Backup was the wrong lead for this house. Return to the tariff, or accept that the array without storage is the right system here.

The general craft — hearing the difference between a reflex, a concern and a real no — is in solar rebuttals and objection handling.

What the pitch never says

• A savings figure the homeowner’s own tariff does not produce.
• “Whole-home backup,” unless the system is actually sized for it.
• A tax credit amount, a rebate figure, or a programme by name that the rep has not confirmed applies to this home this year.
• “Free” — the battery is never free, and the word survives to the contract.
• That the utility is ending net metering on a date the rep has not verified.

Measuring it

Two numbers, kept separately. The team’s own attach rate — batteries on new systems sold, as a share of systems sold — against the published floor for the state, remembering that the floor undercounts and the team’s own figure does not. And the retrofit conversion: storage assessments held per hundred solar homes on the list, and installs per assessment. The first number should sit well above the state floor in any territory where the tariff has changed. The second will be small, and a team that knows it is small will build the retrofit list carefully enough to make it pay.

For the size of the solar stock this all sits on top of — which states have the arrays, counted from the roof rather than from paperwork — see homes with solar by state.

Frequently asked questions