Under California’s NEM 3.0 net billing, the utility pays far less than retail for power you export, so a battery is the top payback lever: it stores cheap midday solar and runs your home through the expensive 4 to 9 pm peak. A home battery runs about $9,000 to $18,000 installed, and the SGIP rebate helps most for income-qualified households. Verify current terms with your utility.
On the three big California utilities, a solar battery has gone from a nice-to-have to the part that decides whether your system pays. The reason is NEM 3.0. Pacific Gas & Electric (PG&E), Southern California Edison (SCE), and San Diego Gas & Electric (SDG&E) now credit the power you export at avoided-cost values that sit far below the retail rate, so banking surplus with the grid no longer works like it did under the old rules. This guide is the deep dive on the storage layer: why a battery is close to essential under net billing, what the SGIP rebate actually pays and who qualifies, what a battery costs in California and how it attaches to payback, how to size one, and the vendor-neutral specs that matter. For the statewide cost and incentive picture start with our California solar hub, for a full panels-plus-battery price breakdown see our California solar cost guide, and for exactly how the export credit works hour by hour see our California NEM 3.0 net billing guide.
Why a battery is close to essential under NEM 3.0
Here is the short version of the mechanism, because the full hourly detail lives in our NEM 3.0 net billing guide. Under the old NEM 2.0 rules, exported power earned a credit near the full retail rate, so the grid worked like a free battery and you could size for the whole roof and bank the extra. Under net billing, the surplus you export at noon is credited at low avoided-cost values, often a few cents, while the power you buy back in the evening still costs the retail rate. That gap is the whole case for storage. A battery lets you hold your cheap midday solar and spend it at home during the 4 to 9 pm peak instead of selling it low and buying it back high.
First-party MySolarFY computed figure. Built August 2026 from cited inputs, not a quote.
To put a number on it: a 6 kW system in Los Angeles produces about 10,029 kWh a year (NREL PVWatts v8), and California’s average residential rate is about 33.25 cents per kWh (EIA, California residential, May 2026). According to MySolarFY’s August 2026 analysis, a 13.5 kWh battery paired with that system can route roughly 4,900 kWh a year through storage, and each stored kWh is worth about 33 cents in avoided retail power under NEM 3.0 instead of the low-single-digit export credit it would earn if you sold it at midday. That is the value the battery protects. It is also why, under net billing, adding storage does more for payback than adding more panels.
One honest caveat up front: on bill savings alone a battery pays back slowly, often 10 years or more, because it adds real upfront cost. Most California homeowners buy storage for the mix of a stronger NEM 3.0 bill, backup power when the grid goes down, and control over the evening peak, not for the export math by itself. Size it to your evening use, not your whole roof.
SGIP: California’s battery rebate, tier by tier
California does not have a state solar tax credit, but it does run the Self-Generation Incentive Program (SGIP), a rebate paid per usable kWh of battery storage and administered through your utility under the California Public Utilities Commission (CPUC SGIP). How much you get depends almost entirely on which tier you qualify for, and the biggest money is reserved for income-qualified and fire-risk households.
| SGIP tier | Approx. rebate (per usable kWh) | Who it is for |
|---|---|---|
| General Market | Roughly $150 per kWh or less, and largely exhausted | Standard residential customers, no income test. Budgets in the big IOU territories are mostly spent, so expect a waitlist or nothing. |
| Equity | About $850 per kWh | Income-qualified households and those in disadvantaged or low-income communities |
| Equity Resiliency | About $1,000 per kWh | Income-qualified homes in high fire-threat districts or that have faced repeated Public Safety Power Shutoffs |
| Residential Solar and Storage Equity (RSSE) | About $1,100 per kWh of battery, plus about $3,100 per kW of solar | Income-qualified households pairing new solar with storage |
Approximate SGIP rebate levels as of August 2026, from CPUC and utility program materials. SGIP budgets step down as they fill and several buckets are on waitlists, so verify the current per-kWh rate, your eligibility, and budget status with your utility and the CPUC before you count on it.
The practical takeaway is blunt. If you are a standard middle-income homeowner, treat SGIP as a small bonus at best, not the reason to buy, because the General Market bucket is modest and largely spent. If your household is income-qualified, or you are in a high fire-risk area or have lived through repeated shutoffs, the Equity and Equity Resiliency tiers can cover a large share of a battery and are worth chasing. Your installer files the SGIP paperwork through your utility, and the rebate is claimed by the system owner, so on a lease or PPA it flows to the company that owns the equipment, not to you.
What a solar battery costs in California
Storage is the single most expensive add-on most homeowners weigh, and California prices track the national ranges. A typical home battery runs about $9,000 to $18,000 fully installed, covering the battery, its inverter, and labor, which works out to roughly $800 to $1,300 per usable kWh (per 2026 installer and marketplace pricing, EnergySage, as of August 2026). Small single-circuit units can start near $5,000, and whole-home setups with two or more batteries can pass $22,000. For the full national breakdown and our cost-per-kWh method see our solar battery cost guide.
| Usable capacity | Typical installed cost (2026) | Computed cost per usable kWh | Common use in a NEM 3.0 home |
|---|---|---|---|
| 5 kWh (single small unit) | $5,000 to $7,000 | about $1,000 to $1,400 | A few essential circuits through the evening |
| 10 kWh | $9,000 to $13,000 | about $900 to $1,300 | Covers most of the 4 to 9 pm peak for an average home |
| 13.5 kWh (popular single unit) | $12,500 to $16,000 | about $925 to $1,185 | The most common single-battery size for full peak shifting |
| 20 to 27 kWh (two units) | $18,000 to $27,000 | about $850 to $1,150 | Whole-home backup plus overnight self-supply |
SolarFY estimate. Cost per usable kWh equals installed cost divided by usable kWh; installed ranges from EnergySage, 2026, with the per-kWh figures our own computation. Government cost models run higher: the EIA models a representative 13.5 kWh residential system near $2,000 per kWh (EIA battery storage study, 2022 dollars), an apples-to-oranges modeled benchmark, not a quote. Actual quotes vary by home, brand, and electrical work.
On attach-payback, be realistic. Where an income-qualified SGIP tier applies, a large rebate can cut the effective battery cost sharply and pull payback in. Without a big SGIP tier, the battery earns its keep mainly through the extra NEM 3.0 self-consumption value, TOU peak avoidance, and backup, and it pays back slowly on the bill math alone. The battery is what makes a NEM 3.0 solar system pencil, but the battery by itself is a long-horizon purchase you buy for value and resilience, not a quick flip.
How to size a battery for a California home
Sizing under net billing is about your evening, not your roof. The goal is to cover the 4 to 9 pm peak window and, ideally, your overnight base load, so you buy as little retail power as possible during expensive hours. Three quick anchors:
- Start from your evening kWh, not your daily total. A typical California home pulls a few kWh across the 4 to 9 pm peak, so a 10 to 13.5 kWh usable battery covers the peak plus some overnight for most homes.
- Add capacity for big evening loads. An EV you charge at night, a heat pump, or a pool pump can double what you need, which is where a second unit or a 20-plus kWh setup comes in.
- Match battery power to what you run at once. Usable kWh is the fuel tank; continuous power output in kW is the engine. A battery with about 5 kW continuous runs everyday circuits, but an AC compressor or EV charger needs more headroom or a larger or second unit.
Bigger is not automatically better under NEM 3.0. Once a battery is large enough to carry your peak and overnight use, extra capacity mostly sits idle, so the sweet spot for most homes is enough to zero out evening grid purchases, not the largest system an installer can quote.
Battery specs that actually matter
Battery marketing leans on brand names, but the spec sheet is where the real differences hide. These are the vendor-neutral specs to compare on any quote, without getting talked into a badge.
| Spec | What it means | What to look for |
|---|---|---|
| Usable vs nominal kWh | Usable is what you actually get; nominal is the label | Compare on usable kWh only, so quotes are apples to apples |
| Chemistry | Most home batteries are lithium iron phosphate (LFP) | LFP is the common choice for home storage on safety and cycle life |
| Continuous power (kW) | How much you can run at once | Around 5 kW or more for everyday loads; more for AC or EV charging |
| Round-trip efficiency | Share of stored energy you get back out | Roughly 90% is typical for a good LFP system |
| Warranty | Years and cycles at a guaranteed capacity | 10 years is standard, with a retained-capacity floor near 70% |
| Backup capability | Whether it powers the home when the grid is down | Confirm it supports islanding and whether it backs the whole home or only chosen circuits |
Home lithium iron phosphate batteries generally carry 10 to 15 year warranties and are rated for thousands of cycles at 70% retained capacity or more, so a battery sized and cycled sensibly should last the bulk of a 20-plus year solar system (verified against manufacturer warranty terms and independent storage analysis, as of August 2026). For a plain-language look at leading models and how they compare, see our best solar batteries for home backup guide. We do not rank installers or link to sellers here; bring the spec list to any quote and compare on the numbers.
Backup power, PSPS, and wildfire resilience
Bill savings are only half of why California homes add storage. The other half is keeping the lights on. California utilities run Public Safety Power Shutoffs (PSPS), cutting power to large areas during high fire-risk weather, and ordinary storm outages happen too. Solar panels alone shut down in an outage for safety, so without a battery your roof goes dark exactly when you need it. A battery that supports islanding keeps your essentials, or your whole home, running through an outage and recharges from your panels the next day.
This resilience value is also why the SGIP Equity Resiliency tier exists and pays the most: it is aimed at income-qualified homes in high fire-threat districts and those hit by repeated shutoffs. If that is your situation, backup is not a bonus, it is the point, and the rebate can cover a large share of the system. For everyone else, treat backup as a real but hard-to-price benefit on top of the NEM 3.0 bill math.
The federal tax credit and batteries in 2026
Be careful with any 2026 pitch that leans on the old 30% federal credit. The federal residential clean energy credit (Section 25D), which since 2022 covered home batteries of 3 kWh or more, ended for expenditures made after December 31, 2025 (IRS; ENERGY STAR). A homeowner buying a battery in 2026 cannot claim it. The separate commercial credit (Section 48E) goes to the business that owns the equipment, so on a lease or PPA it flows to that company, not to you. Solar and storage are not free, and no legitimate program makes them free. The real California money for a battery now is SGIP for those who qualify, plus the NEM 3.0 self-consumption and backup value, not a federal tax credit.
See which solar and battery programs fit your California ZIP code
SGIP tiers, NEM 3.0 export credits, TOU peaks, and installer availability change by utility and location. Enter your ZIP and we’ll match you with licensed installers who serve your area.
Free to check. About a minute. No credit pull to check.
Submitted securely and used to match you with licensed installers in your area. Some homeowners may qualify for $0-up-front lease/PPA options where available.
California solar battery FAQ
Do I need a battery to go solar in California?
You are not required to have one, but under NEM 3.0 net billing a battery captures far more value because it stores cheap midday power for the expensive 4 to 9 pm peak instead of exporting it for a few cents. On PG&E, SCE, and SDG&E, most new systems now pair panels with storage. As of August 2026.
How much is the SGIP battery rebate in 2026?
It depends on your tier. The General Market bucket is roughly $150 per kWh or less and largely exhausted, while income-qualified Equity tiers run about $850 to $1,100 per usable kWh. Budgets step down and several buckets are on waitlists, so verify the current rate and your eligibility with your utility and the CPUC. As of August 2026.
How much does a home battery cost in California?
A typical home battery runs about $9,000 to $18,000 fully installed, or roughly $800 to $1,300 per usable kWh, including the battery, inverter, and labor. Small single-circuit units can start near $5,000 and whole-home setups can pass $22,000. Income-qualified SGIP tiers can cut the effective cost sharply. As of August 2026.
Is there still a federal tax credit for batteries?
No. The 30% federal residential credit (Section 25D) that covered home batteries ended for expenditures made after December 31, 2025, so a homeowner buying a battery in 2026 cannot claim it. The commercial 48E credit goes to the company that owns the system, such as on a lease or PPA, not to the homeowner.
What size battery do I need under NEM 3.0?
Size to your evening use, not your whole roof. A 10 to 13.5 kWh usable battery covers the 4 to 9 pm peak plus some overnight for most California homes, while big evening loads like an EV, heat pump, or pool pump can call for 20 kWh or more. Match continuous power in kW to what you run at once. As of August 2026.
Does a battery power my home during a PSPS or outage?
Yes, if it supports islanding. Solar panels alone shut off during an outage for safety, but a battery with backup capability keeps your essentials or whole home running through a Public Safety Power Shutoff or storm outage and recharges from your panels the next day. Confirm whether the system backs the whole home or only selected circuits.
Reviewed August 2026 by the MySolarFY editorial team. Battery and SGIP details were verified against the linked CPUC SGIP and Net Billing Tariff materials, IRS and ENERGY STAR guidance on the Section 25D residential credit that ended for expenditures made after December 31, 2025, EIA electricity rates, and NREL PVWatts production, as of August 2026. SGIP per-kWh rebate levels, budget and waitlist status, TOU windows, and export values change, so confirm current terms with your utility (PG&E, SCE, SDG&E, LADWP, or SMUD) and the CPUC before you decide. The figures here are illustrations built from the cited inputs, not a quote or a savings guarantee. MySolarFY does not provide tax or financial advice; consult a licensed professional. Learn more about how we work.
MySolarFY is a free service that matches homeowners with licensed solar installers. We are not an installer, financing company, or government program. “No up-front cost” refers to qualifying lease or PPA financing, where eligible homeowners may have no out-of-pocket cost at installation. Lease and PPA terms typically run 20 to 25 years, may include an annual price escalator, and total payments may exceed the cost of a cash purchase; on a lease or PPA the California incentives, including SGIP, go to the company that owns the system, not the homeowner. Homeowners do not get the federal residential credit that ended after December 31, 2025. Solar panels and batteries are not free and monthly payments apply. Eligibility, savings, incentives, and rates vary and are not guaranteed. See our full disclaimer.
