Solar / Guides
Is a home battery worth it in 2026?
A 13.5 kWh home battery at $12,000, with no federal credit in 2026, adds $17,011 over 25 years on a 5.94 kW system in San Diego, California, on a $300-a-month bill — and pays in 2 of the 11 states we publish. The difference is not the sun or the price of the battery. It is how your utility credits exports.
The model's two battery assumptions are literature defaults, not measurements, and they are printed below and on the methodology page. Treat the sign as robust and the size as directional.
What a battery changes in the model
- Self-consumption rises from 40% to 75%
- The share of what the panels produce that the house uses itself instead of exporting. Share of generation consumed on site rather than exported. Irrelevant under 1:1 net metering, decisive under NEM 3.0.
- Installed cost: $12,000 for 13.5 kWh
- Added to the system price on day one. In 2026 no federal credit reduces it; state credits that are a percentage of system cost apply to it where their caps allow.
- What a moved kilowatt-hour is worth
- Retail rate minus export credit. Under full net metering that is zero — the grid already pays retail for exports — so a battery can only cost. Under net billing at 25% of retail, as in California, it is 75% of the rate.
Assumptions from finance/defaults.json, verified 2026-09-04. Formulas: the year-by-year model.
No federal credit in 2026
Through 2025 the federal credit covered storage on the same terms as panels: Battery storage technology (beginning in 2023)
qualified, provided Battery storage technology must have a capacity of at least 3 kilowatt hours.
It ended with the rest of the credit — 25D unavailable for property placed in service after 2025-12-31 (One Big Beautiful Bill Act) — so a battery placed in service in 2026 earns nothing federally, whether or not the panels it pairs with were installed in time.IRS, page updated 2026-07-04, read 2026-09-05. More on the tax-credit page.
Where it pays: California
A 5.94 kW system in San Diego, California, on a $300-a-month bill: 34.74¢/kWh, exports credited at 25% of retail (net billing, export credited below retail). Without a battery, 60% of production is exported and paid a quarter of its worth.
| Cash purchase | No battery | With battery | Change |
|---|---|---|---|
| Net cost | $14,729 | $26,729 | +$12,000 |
| Year-1 net savings | $1,751 | $2,658 | +$907 |
| Payback | 7.8 yr | 9.2 yr | +1.4 yr |
| 25-year net | $40,508 | $57,519 | +$17,011 |
| Lease / PPA, 25-year net | −$20,633 | $8,378 | +$29,011 |
The battery raises lifetime savings and lengthens payback at once: more saved every year, more paid on day one. Both are true; the 25-year net is the verdict.
Cash position with and without storage
Table view
| Year | Cash, no battery | Cash, with battery |
|---|---|---|
| 0 | −$14,729 | −$26,729 |
| 5 | −$5,590 | −$12,869 |
| 10 | $4,572 | $2,501 |
| 15 | $14,062 | $17,739 |
| 20 | $26,598 | $36,615 |
| 25 | $40,508 | $57,519 |
With and without, by state
The same $200-a-month bill in every state we publish, cash, quoted prices, with and without the battery. Sorted by what the battery adds.
| State | Export credit | 25-yr net, no battery | 25-yr net, with battery | Battery adds | Payback with |
|---|---|---|---|---|---|
| California | 25% net billing, export credited below retail | $24,525 | $31,463 | +$6,938 | 12.3 yr |
| Arizona | 50% net billing, export credited below retail | $27,237 | $27,863 | +$626 | 14.9 yr |
| Texas | 90% varies by utility or retail provider | $41,404 | $31,929 | −$9,475 | 14.6 yr |
| New York | 100% full retail net metering | $54,330 | $43,241 | −$11,089 | 10.1 yr |
| Massachusetts | 100% full retail net metering | $50,567 | $38,567 | −$12,000 | 12.5 yr |
| Connecticut | 100% full retail net metering | $46,443 | $34,443 | −$12,000 | 14 yr |
| Illinois | 100% full retail net metering | $40,755 | $28,755 | −$12,000 | 16 yr |
| New Jersey | 100% full retail net metering | $48,720 | $36,720 | −$12,000 | 13.2 yr |
| Maryland | 100% full retail net metering | $47,154 | $35,154 | −$12,000 | 13.8 yr |
| Pennsylvania | 100% full retail net metering | $46,886 | $34,886 | −$12,000 | 13.9 yr |
| Florida | 100% full retail net metering | $46,082 | $34,082 | −$12,000 | 14.1 yr |
A battery on a lease
A lease charges for every kilowatt-hour produced; a battery lets you use more of what you are charged for instead of exporting it at 25% of retail. On a 5.94 kW system in San Diego, California, on a $300-a-month bill the lease goes from −$20,633 to $8,378 over 25 years (+$29,011). The model assumes the battery is bought; who supplies it under a lease, and at what rate, is a contract question it does not see. The lease-vs-buy page has the mechanism.
What this page does not count
- Battery degradation and replacement. The model runs one battery for 25 years at constant capacity; a real one will not.
- Backup value. Power through an outage is the reason many buyers install one, and it is worth something the model does not price.
- Time-of-use arbitrage. Charging cheap and discharging at peak rates, where tariffs allow it. The model uses one average rate.
- Demand charges and grid-access fees that some utilities apply to solar customers.
- Utility storage programmes that pay for grid services.
Each of these moves the answer, most of them in the battery's favour. What is not modelled.
State programmes
California: No state income-tax credit and no statewide rebate for residential PV. SGIP general-market residential storage funding ran through 2025; the Residential Solar and Storage Equity budget ($280M, reservations from 2025-06-02) is income-qualified. Recorded on the California page with its source and read date.The other states we publish record no battery-specific programme; the state pages say what was checked.
The battery's own payback
Strip the panels out and look at the battery alone: what it adds to the price, what it adds to the savings each year, and how long the second takes to repay the first. The same $200-a-month bill in every state we publish.
| State | Export credit | Battery adds to cost | Adds to year-1 savings | Pays for itself in |
|---|---|---|---|---|
| California | 25% | $12,000 | +$592 | 17.2 yr |
| Arizona | 50% | $12,000 | +$395 | 24 yr |
| Texas | 90% | $12,000 | +$79 | never |
| New York | 100% | $11,089 | $0 | never |
| Massachusetts | 100% | $12,000 | $0 | never |
| Connecticut | 100% | $12,000 | $0 | never |
| Illinois | 100% | $12,000 | $0 | never |
| New Jersey | 100% | $12,000 | $0 | never |
| Maryland | 100% | $12,000 | $0 | never |
| Pennsylvania | 100% | $12,000 | $0 | never |
| Florida | 100% | $12,000 | $0 | never |
A battery that pays for itself inside the 25 years raises the whole system's 25-year net; one that does not lowers it by roughly its price. The two assumptions behind every row — self-consumption 40% → 75%, $12,000 installed — are literature defaults.
Questions
- Is a solar battery worth it in 2026?
- It depends almost entirely on how your utility credits exports. On a 5.94 kW system in San Diego, California, on a $300-a-month bill, where exports are credited at 25% of retail, a 13.5 kWh battery at $12,000 adds $17,011 over 25 years and moves payback from 7.8 yr to 9.2 yr. In the 9 states we publish with full-retail export credit, the same battery reduces the 25-year net by $9,475 to $12,000: there is nothing for it to save.
- Does the federal tax credit cover batteries?
- Not in 2026. Through 2025 it did: "Battery storage technology (beginning in 2023)" qualified, provided "Battery storage technology must have a capacity of at least 3 kilowatt hours." It ended with the rest of the credit for property placed in service after 31 December 2025. Source: https://www.irs.gov/credits-deductions/residential-clean-energy-credit, read 2026-09-05.
- How does the model decide whether a battery pays?
- Two assumptions, both published: a battery raises the share of production used on site from 40% to 75%, and it costs $12,000 installed for 13.5 kWh. Every kilowatt-hour moved from export to self-use is worth the retail rate minus the export credit. Under full net metering that difference is zero, so the battery cannot pay; under net billing it is most of the rate.
- Can a battery fix a lease that loses money?
- Partly. On a 5.94 kW system in San Diego, California, on a $300-a-month bill, the lease is −$20,633 over 25 years without a battery and $8,378 with one (+$29,011): more of the production the lease charges for is used rather than exported at a loss. Whether the provider supplies the battery, and at what rate, is a contract question the model does not see.
- What does the model leave out about batteries?
- Battery degradation and replacement within 25 years, backup value during outages, time-of-use arbitrage, demand charges, and any utility storage programme. All of these move the answer; none is modelled yet. The methodology page lists them.
- How long does the battery itself take to pay back?
- Taking only what the battery adds — $12,000 of cost against the extra savings it produces each year — it pays for itself in 17.2 years in California, 24 years in Arizona on a $200 bill. In the other 9 states we publish it never does: under full-retail export credit there is nothing for it to save.
- Does a battery ever pay under full net metering?
- Not in this model. When the utility credits exports at the retail rate, a kilowatt-hour stored and used later is worth exactly what it would have earned exported, so the battery saves nothing and costs $12,000. Backup power and time-of-use tariffs — not modelled — are the reasons people install one anyway.
- Are there battery rebates?
- California: No state income-tax credit and no statewide rebate for residential PV. SGIP general-market residential storage funding ran through 2025; the Residential Solar and Storage Equity budget ($280M, reservations from 2025-06-02) is income-qualified. Other states we publish record no battery-specific programme. The state pages carry the sources.
This is general information computed from published data and statute, each cited with the date it was read. It is a screening estimate, not a quote, and not financial or tax advice: confirm the figures against real quotes and with a professional before you rely on them.
Published 5 September 2026. Data last verified 5 September 2026. About the author.