Home Battery Storage
The piece that makes solar actually pay off.
Under California’s Net Billing Tariff, sending power back to the grid earns just pennies. A home battery lets you keep your own energy and use it when power is most expensive — and keeps your lights on when the grid goes down.
Why storage, why now
Under NEM 3.0, the battery is the strategy
California changed the rules in 2023. Before then, exporting extra solar to the grid earned you near-retail credit — so most homes ran panels alone. Today, under the Net Billing Tariff, that same exported power is worth only a few cents per kWh, while the electricity you buy back in the evening costs many times more.
A battery closes that gap. It stores the surplus your panels make at midday and releases it in the pricey late-afternoon and evening window — so you’re using your own power instead of buying expensive grid power. That single shift is what turns a solar system from “decent” into a genuinely strong long-term investment in 2026.
And there’s a benefit no export credit ever gave you: when the grid goes down, a properly configured battery keeps your essentials — fridge, Wi-Fi, medical devices, a few lights — running through the outage.
What a battery does for you
Three reasons Bay Area homes add storage
Beat peak rates
Store cheap midday sun and run your home through the expensive 4–9 p.m. window instead of buying from the grid.
Backup power
Keep your fridge, internet, and essential circuits alive during PG&E outages and Public Safety Power Shutoffs.
More self-use, less waste
Capture the solar you’d otherwise export for pennies, and use far more of what your own roof produces.
Not just one brand
Batteries we install
We install the battery that fits your home, your solar and your budget, not just one brand. Here is how the most popular options compare.
| Spec | Tesla Powerwall 3 | FranklinWH aPower 2 | SolarEdge Nexis | EG4 WallMount PowerPro | Lunar System | Enphase IQ Battery 10C |
|---|---|---|---|---|---|---|
| Storage | 13.5 kWh | 15 kWh | 4.65–18.6 kWh usable per stack | 14.3 kWh (EG4 recommends using 80%) | 15–30 kWh | 10 kWh |
| Continuous power | 11.5 kW | 10 kW | Up to 13 kW per stack | Set by the EG4 inverter | 9.6 kW (15 kWh model: 7.2 kW without sun) | 7.08 kW |
| Starts heavy loads (motor start) | 185 LRA | 185 LRA | 185 LRA (3 or more blocks) | Set by the EG4 inverter | 134 LRA | Up to 90 LRA |
| How it connects | Built-in solar inverter, up to 20 kW DC of solar | AC-coupled, works with any solar inverter brand | DC-coupled with the SolarEdge Nexis inverter | 48 V battery paired with an EG4 hybrid inverter | Built-in solar inverter, up to 15 kW DC of solar | AC-coupled with built-in microinverters |
| Expandable to | 4 Powerwall 3 units + 3 expansion units | 15 units (225 kWh) per aGate | 4 stacks per inverter (78.4 kWh) | Depends on the EG4 inverter | 30 kWh in one tower | 8 units (80 kWh) |
| Warranty | 10 years | 15 years or 60 MWh | 10 years | 10 years (prorated) | 12.5 years | 15 years or 6,000 cycles |
Swipe the table sideways to see every battery.
Specs come from each manufacturer’s datasheet as of October 2026 and can depend on how the system is set up. SolarEdge lists some Nexis specs as preliminary. We also install other brands; ask us.
Sources: Tesla Powerwall 3 datasheet, FranklinWH aPower 2 datasheet, FranklinWH aPower 2 overview, SolarEdge Nexis datasheet, EG4 WallMount spec sheet, EG4 warranty, Lunar System, Lunar System datasheet, Enphase IQ Battery 10C datasheet, Enphase system planning guide.
Common questions
Battery storage, answered
Do I really need a battery with solar?
Not strictly — but under the Net Billing Tariff it’s what makes the economics work. Because exported power now earns only a few cents per kWh, storing your production and using it in peak hours captures far more value than selling it back. Most new Bay Area systems pair solar with a battery for this reason.
Can I add a battery to my existing solar system?
Often yes. Many existing solar setups can be retrofitted with storage, though the details depend on your inverter and panel. If you’re on an older NEM 1.0 or 2.0 agreement, adding a battery can usually be done without losing your grandfathered rate — we’ll confirm before anything changes.
How long does a battery keep my home running in an outage?
It depends on your battery’s capacity and what you’re powering. Sized for essentials — fridge, Wi-Fi, lights, key outlets — a typical home battery can carry you through the evening and overnight, then recharge from your panels the next day. We size backup to your priorities.
How much does home battery storage cost?
A battery typically adds a meaningful amount on top of a solar system, varying by capacity and how many you need for backup. The federal residential tax credit that once helped offset this ended for purchases at the end of 2025, so we quote real 2026 pricing and show you the payback honestly in your assessment.
See what solar plus storage would save you.
A free assessment with a written estimate and honest payback math — no pressure to sign.