Short answer: a lot of East Bay homes should not buy one yet.
That is not the answer most solar companies give, and it costs us sales. But we would rather tell you the truth about a $15,000 decision than sell you a battery that takes twenty years to pay back on a $180 PG&E bill. There is a bill level where storage clearly makes sense, one where it clearly does not, and a reason to buy one that has nothing to do with payback at all.
Rates and rules verified 30 August 2026.
What does a battery actually do for you under NEM 3.0?
It changes what happens to the power your panels make while you are not home to use it.
Under the old net metering rules, exporting was fine — you were credited close to what you paid, so the grid worked like a free battery. Under NEM 3.0, the Net Billing Tariff that applies to every PG&E, SCE and SDG&E system connected since 15 April 2023, exports earn hourly avoided-cost rates worth roughly a quarter of what NEM 2.0 paid. Midday exports in spring are worth very little.
Meanwhile you still buy evening power at the full volumetric rate, around 36 cents a kWh.
That gap is the whole story. A kilowatt-hour your panels make at 1pm is worth a few cents exported and around 36 cents used at home. A battery moves kilowatt-hours from the cheap column to the expensive column. That is the entire economic case — not generating more, just selling less of what you generate at a bad price. We go through how those export rates are set in NEM 3.0 export rates and what PG&E really pays you.
NEM 3.0 applies to PG&E, SCE and SDG&E. This post is written for PG&E customers, which is nearly everyone in Contra Costa County — including households on MCE and other community choice programmes, since PG&E still owns the wires and the export rules.
How much of a PG&E bill can storage realistically remove?
Our own numbers, from the same calculator we use on real proposals, for a household with a $220 monthly PG&E bill:
| | Solar only | Solar + battery |
|—|—|—|
| System | 4.5 kW | 4.5 kW + one battery |
| Share of bill offset | about 42% | roughly 55–75% |
| First-year savings | about $1,105 | higher, in proportion |
| Payback | about 11.4 years | about 16 years |
Read the last row twice. At a $220 bill, adding a battery makes your payback about five years longer, not shorter. It raises the share of your bill you cover, but it costs roughly $15,000 to do that, and on a bill that size there is not enough evening consumption to earn it back quickly. Two things drive this:
There is a floor no battery can reach. Since March 2026 every PG&E residential customer pays a Base Services Charge of about $24 a month, and PG&E states it “is not eligible to be offset by monthly generation credits.” That $24 is untouchable by panels and by storage. On a $220 bill it puts a hard ceiling of 89 percent on any offset figure.
A battery only pays for the power it actually shifts. One that sits half-empty because your evening use is modest earns half as much. Big evening loads — air conditioning through a Concord August, an EV charging at home, a pool pump, electric heat pumps — are what make storage work.
The rough rule we use: a battery starts to pencil on payback grounds somewhere around $250 to $300 a month, and gets more convincing from there. Below that, the numbers say buy the solar now and revisit storage later. Run your own bill through our savings calculator to see where you land.
Is a battery worth it if you’ve never lost power?
If the only question is payback, and your bill is under about $250 a month, then no, not yet.
Buying solar first and adding a battery in a few years is a perfectly good plan. Retrofit wiring costs more than doing it all at once, but paying an extra couple of thousand later beats spending $15,000 now on equipment that does not earn its keep. Tell us at design time that you might add storage later and we will leave room for it — panel space, main breaker rating, conduit routing. That costs almost nothing now and saves real money in year four.
The honest exception is resilience, and it is not a payback calculation at all. Some households have a reason to keep the lights on that no spreadsheet captures: a home medical device, a well pump, someone working from home who cannot lose a day, a family member who should not be in a house at 100°F with no air conditioning. If that is you, the battery is insurance — evaluate it the way you evaluate insurance. What does the bad day cost, and what will you pay to avoid it?
We will not pretend those are the same argument. Plenty of quotes blur them together, presenting a resilience benefit and a payback figure as if they stack. They do not.
What does a battery run during a PSPS shutoff — and for how long?
This is where vague marketing does the most damage. “Keeps your essentials running” tells you nothing. A single battery of the type we specify holds between 5 and 15 kWh of usable energy and delivers a limited amount of power at any one moment:
| Battery | Usable energy | Continuous output |
|—|—|—|
| Tesla Powerwall 3 | 13.5 kWh | up to 11.5 kW |
| FranklinWH aPower 2 | 15 kWh | 10 kW |
| Enphase IQ Battery 5P | 5.0 kWh (stackable) | 3.84 kW |
Manufacturer datasheet figures, checked August 2026.
Two limits matter and people usually think about only one. Energy (kWh) sets how long you can run. Power (kW) sets what you can run at all. A battery with plenty of energy left will still trip if asked to start an air conditioner it cannot support.
A realistic backup set for most homes — refrigerator, LED lighting, wifi and networking, phone and laptop charging, a garage door, a handful of dedicated outlets, a gas furnace’s blower and controls — typically lands around 4 to 6 kWh a day in our experience. Against 13.5 kWh of usable capacity, that is roughly two days with no sun at all.
But an outage in Contra Costa rarely means no sun. If your panels are working and the system is configured to recharge the battery during daylight, a September PSPS event looks more like this: the battery covers the evening and overnight, the panels refill it the next morning, and you keep going for as long as the weather holds. That is better than the two-day number suggests.
What changes the answer sharply:
- Central air conditioning. A compressor drawing 3 to 5 kW will empty a 13.5 kWh battery in a few hours. If you want AC during an August outage in Concord or Walnut Creek, that is two batteries and a serious conversation about which rooms.
- Electric range, electric dryer, EV charging. We usually leave these off the backup panel. You can cook on the barbecue for a day; you cannot argue with a flat battery.
- Well pumps. Common in Lafayette, Alamo and the rural edges of Danville, and they have a large starting surge. The power ratings above decide whether a pump starts, not the kWh figure.
- Whole-home versus partial backup. Backing up a selected sub-panel is cheaper and far more predictable. Most of the disappointment we see comes from people sold “whole-home backup” who did not know what their whole home draws.
We size backup from your real loads, measured at your panel, not from a chart. That is a design job, and we do it ourselves before any licensed contractor partner touches the house.
Are there still battery rebates in California in 2026?
Here we are going to be less specific than you want, on purpose.
California does run a state storage incentive programme — the Self-Generation Incentive Program. Its budget, tiers and eligibility rules have changed repeatedly, and categories have opened and closed at different times. Any blog post printing a dollar amount for it is telling you what was true the day it was written.
So assume zero when you are deciding. If a battery only makes sense because of a rebate, it does not make sense yet. Ask us and we will check the programme’s current status and your eligibility on the day you ask, including when the answer is no.
On the federal side, the 30 percent residential tax credit expired on 31 December 2025. Any quote including it needs re-checking. More in solar tax credits in 2026.
Powerwall, Franklin, Enphase — how do we choose for a given home?
We are not loyal to a brand. We choose on five things, roughly in this order.
1. What has to keep running. This sets the continuous and peak power you need, and it usually rules out options before capacity does. A house with a well pump and a big AC compressor has different requirements from a townhouse with a gas furnace.
2. How many hours you want. Usable kWh matched against the daily consumption of the loads you chose to back up. A multiplication, not a guess.
3. What your existing electrical system will take. Main panel rating, breaker space, service entrance, and whether you already have solar with its own inverters. Retrofitting storage onto an existing array is a different design problem from a new system built as one piece.
4. Where it physically goes. Batteries want a shaded, ventilated wall — a garage interior beats a west-facing exterior wall in a Concord summer. Setback and clearance rules apply and are not negotiable.
5. Warranty terms as written. Not the headline number, the terms in the document: how many years, how much throughput, and who honours it. We hand you the manufacturer’s warranty and your written contract, and we make no performance promises beyond what those say.
Modularity matters too. A stackable 5 kWh unit lets a household start smaller and expand; a single 13.5 or 15 kWh unit is usually better value per kWh if you know you need the capacity now.
The wider “is any of this worth it” question is covered in is solar still worth it in Contra Costa in 2026, and our residential solar page explains how we design around your usage rather than around a package.
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Free consultation, and we will tell you no.
Send us twelve months of PG&E usage and we will model solar-only against solar-plus-battery on your actual bill and rate plan. If storage does not pay for you yet, we will say so and tell you what would have to change. No pressure.
Run the numbers yourself, or get in touch and we will do it with you.
Singh Solar Couple designs and project-manages residential and commercial solar and storage across Contra Costa County, from Concord and Walnut Creek out to Danville and Lafayette. Navjot and Nam bring over a decade of California solar experience. The physical installation is carried out by our licensed contractor partners.