Solar Battery Storage for Sacramento Homes
Batteries changed from a luxury to the centrepiece of a well-designed system the moment export credits fell below retail rates. Here is how to size one properly.
- Typical usable capacity10–20 kWh residential
- Backup coversNominated critical circuits
- WarrantyCommonly 10 years
- SGIP rebatePG&E customers only — not SMUD
Why storage stopped being optional
For years the argument against a home battery was simple arithmetic: if your utility credited exported solar at roughly the retail rate, the grid was your battery, and a far cheaper one. That is no longer how most California export credits work.
Under California’s net billing tariff — which governs PG&E customers in Placer, El Dorado, Yolo and Solano counties — exported energy is credited near avoided cost rather than retail. The gap between what you are paid for an exported kilowatt-hour and what you pay to buy one back in the evening is exactly the gap a battery closes. SMUD, Roseville Electric and Lodi Electric each run their own structures, which is why the storage case has to be worked out per utility rather than assumed. See the utility comparison.
What a battery actually does for a Sacramento home
1. Time-shifts your own power into the expensive hours
Your array peaks around midday. Your usage — and the expensive time-of-use window — peaks in the late afternoon and evening. A battery stores the midday surplus and releases it into the 4pm–9pm window instead of selling it cheaply and buying it back dearly.
2. Keeps essential circuits running in an outage
This is the reason most people actually buy one. A grid-tied array without storage shuts down in an outage — a safety requirement so it cannot backfeed a line a utility crew is working on. With a battery, a backup-capable inverter and a critical-loads subpanel, the circuits you nominate keep running.
3. Covers demand you cannot shift
Medical equipment, a well pump on a rural Wilton or Rio Linda property, a home office, a freezer. If losing power is genuinely disruptive rather than merely annoying, that changes the calculation.
Sizing a battery properly
The two numbers that matter are usable capacity in kilowatt-hours and continuous power output in kilowatts. Capacity determines how long you can run; power output determines what you can run at the same time.
| Goal | Typical usable capacity | What it realistically covers |
|---|---|---|
| Essential backup only | ~10–13 kWh | Fridge, internet, lighting, a few outlets, overnight |
| Evening peak shifting | ~13–20 kWh | Most household evening usage moved off the expensive window |
| Backup plus air conditioning | ~20–30 kWh+ | Requires high continuous output as well as capacity — AC start-up surge is the constraint, not the stored energy |
Air conditioning is where most backup expectations break down. A central AC unit has a large start-up surge, and a battery that comfortably runs your fridge for two days may not start your condenser at all. If cooling through an outage matters to you, say so at the design stage — it changes the equipment, not just the size.
Incentives for storage
California’s Self-Generation Incentive Program (SGIP) has provided rebates toward residential storage, with larger amounts for customers in high fire-threat districts, on medical baseline, or meeting low-income criteria. SGIP is administered through the state’s investor-owned utilities, so it applies to PG&E customers in the foothill and Yolo/Solano parts of our service area — not to SMUD, Roseville Electric or Lodi Electric customers, who fall outside that programme. Funding tiers step down as they are claimed and availability changes, so treat any rebate figure as something to verify rather than assume.
The honest caveat
Storage is the most expensive component per kilowatt-hour delivered in a solar system, and under some rate structures it does not pay back on economics alone within its warranty. If your reason for wanting one is outage resilience, that is a perfectly good reason — but it should be an informed purchase, not one justified by optimistic savings arithmetic.
Retrofitting storage to an existing array
Usually possible, and increasingly common. The two things that decide how straightforward it is are your existing inverter architecture — some are storage-ready, many are not — and whether there is space and capacity at the main panel for a critical-loads subpanel. Adding AC- coupled storage to an older string system is a well-trodden path. We service and upgrade systems of any brand, including ones we did not install.
Questions about solar battery storage
Can a battery run my whole house in an outage?
Possibly, but it is not the default and it is not cheap. Most installations back up a nominated set of critical circuits through a subpanel — fridge, lighting, internet, a few outlets, sometimes a furnace fan. Whole-home backup including central air conditioning needs substantially more capacity and, more importantly, much higher continuous and surge output.
How long do home batteries last?
Current lithium-iron-phosphate residential batteries typically carry ten-year warranties with a guaranteed remaining capacity at the end of the term — commonly around 70%. They do not simply stop at ten years; they continue at gradually reduced capacity. Note that this is shorter than the twenty-five year panel warranty, which matters when you compare lifetime costs.
Do I need a battery if I am on SMUD?
Less urgently than a PG&E customer, but it depends on your rate and your usage pattern. SMUD operates its own solar rate structure rather than the state net billing tariff, so the export-versus-retail gap is different. The only way to answer it properly is to model your own usage against your actual rate schedule — which is part of what our free quote does.
Is it cheaper to add a battery now or later?
Adding it with the array is generally cheaper in labour and electrical work, and it lets us design the main panel and conduit for it from the start. Adding later is entirely feasible but you pay some of that work twice. If storage is a probable future step rather than a certain one, tell us — we can design in the headroom without buying the battery.
Where does the battery get installed?
Garage wall, exterior wall or occasionally a utility room, depending on the unit’s temperature rating and local code. Sacramento summers matter here: an uninsulated garage or a west-facing exterior wall can push a battery beyond its optimal temperature band, which shortens its life. Placement is a design decision, not an afterthought.
See what solar would actually cost on your roof.
Every quote is built from your real roof, your real shade and your real power bill — not a guess from a call centre. It is free, and there is no obligation to move forward.