A solar battery backup keeps your lights, fridge and internet on when the grid goes down — charged by your own rooftop panels, not by a fuel can. Here is how it works, how to size it, and which NovaBESS LiFePO4 options fit your home.
Solar battery backup pairs a rooftop PV array with a home battery and a hybrid inverter. During the day your panels charge the battery; at night or during an outage, the battery powers your home through the inverter. There is no grid connection needed to keep essentials running — the system "islands" away from the grid the moment it detects a blackout and switches to stored solar energy in milliseconds.
It is the quiet, fuel-free alternative to a generator: instead of burning petrol or diesel, you draw on energy your roof already collected. And unlike a bare generator, a solar battery backup also earns its keep every single day by storing excess solar for evening use — see solar self-consumption with HomeWall.
Your rooftop PV array produces DC power from sunlight — more than your home uses at midday.
A hybrid inverter routes surplus solar into the LiFePO4 battery instead of exporting it all to the grid.
At night or when solar is low, the inverter discharges the battery to run your backed-up loads first.
When the grid drops, the system isolates and powers your home from the battery in milliseconds — automatic.
The same bank that covers a blackout also shifts your daily solar to the evening, cutting your grid bill. Run the payback calculator to see the lifetime saving versus staying on the grid.
| Factor | Solar battery backup | Generator |
|---|---|---|
| Start time | Milliseconds, automatic | Seconds–minutes, manual pull/fuel |
| Noise | Silent | 60–80+ dB |
| Fuel | None — charged by sun | Petrol / diesel, stored & refilled |
| Emissions | Zero at point of use | CO₂, fumes, ventilation risk |
| Daily value | Also shifts solar to evening, lowers bill | Sits idle except during outages |
| Best for | Fridges, internet, medical, daily outages | Long multi-day runs as fallback |
Full comparison: Home battery vs generator. Many homes run both — battery for the daily gaps, generator for extended blackouts.
Size by usable kWh, not by the inverter's headline number. Add up the loads you want to back up (fridge, lights, internet, well pump, a window AC), multiply by the hours of autonomy you need, then divide by depth of discharge. Evening solar self-use usually lands at 5–15 kWh; whole-house or off-grid backup climbs to 20–60 kWh.
LiFePO4 gives 80–100% depth of discharge, so a 10 kWh nameplate delivers close to 10 kWh usable — unlike lead-acid, which effectively halves. Use the solar battery size calculator to turn your PV array and daily usage into a recommended capacity and model in 30 seconds. Sizing purely for outages? Open the solar battery backup calculator — enter your loads and hours of autonomy to get the exact kWh.
For a battery mounted in or next to your home, LiFePO4 (LFP) beats the alternatives on the two things that matter most for backup: safety and lifespan. It is thermally stable (very low fire risk), supports 80–100% depth of discharge, and is rated for 4,000–6,000 cycles. NMC (used in many EV-derived home units) packs more energy per kilo but degrades faster and runs hotter; lead-acid is cheap up front yet lasts only ~500 cycles and needs maintenance. See LiFePO4 vs lead-acid for home storage and the honest LiFePO4 drawbacks write-up.
Ultra-slim, quiet, LCD display. Pick 2.5 / 5.1 / 10.2 kWh and parallel up to 15 units (~153 kWh). 5,000 cycles at 80% DoD, 15-year design life, IP54, CE/UN38.3/UL/IEC.
Stack 5 / 10 / 15 kWh modules to 60 kWh. 51.2 V nominal, 100 A per stack, IP54, -25°C to +50°C, UN38.3. Scales with the building instead of forcing one fixed block.
In 2026, LiFePO4 equipment typically runs $400–900 per usable kWh; turnkey installed systems run $800–1,500 per kWh. The honest comparison is lifetime cost per kWh-cycle: LiFePO4 lands near $0.12 versus ~$0.50 for lead-acid. Want a branded turnkey alternative? See our Tesla Powerwall alternative comparison, or the full residential battery storage buying guide.
Open the cost-per-kWh calculator — enter your capacity and quoted price to see where you land against 2026 market ranges, no email required.
Solar battery backup is a home energy setup where rooftop solar panels charge a battery, and that stored energy powers your home when the grid goes down (or at night). The battery sits between your panels and your loads, so when an outage hits, an inverter switches to battery power in milliseconds — no fuel, no noise, no manual start.
During normal operation, solar charges the battery and your home uses solar first, then battery, then grid. When the grid drops, a hybrid inverter isolates your home from the grid (islanding) and draws from the battery through the inverter. Sunlight the next day recharges the bank, so a multi-day outage stays covered as long as the battery has capacity.
Size by daily usable kWh of the loads you want to back up, times your target hours of autonomy, divided by depth of discharge. Evening solar self-use usually needs 5–15 kWh; whole-house or off-grid backup climbs to 20–60 kWh. Use our solar battery size calculator to get a number from your PV array and daily usage.
For most homes, yes. A battery starts in milliseconds, runs silent, needs no fuel, and emits nothing — ideal for fridges, internet and medical loads. A generator is louder, needs fuel, and takes seconds to start. Many homes run both: battery for daily outages and short gaps, generator as a long-run fallback. See our battery vs generator breakdown.
Usually yes. If you already have a hybrid or battery-ready inverter, you can add a compatible battery (like NovaBESS HomeWall or HomeStack over CAN/RS485). If your inverter is grid-tie only, you may need an AC-coupled battery or a hybrid inverter upgrade. Tell us your inverter brand and we will confirm the simplest path.
In 2026, LiFePO4 equipment typically runs $400–900 per usable kWh; turnkey installed systems run $800–1,500 per kWh. The lifetime view matters most: spread over 5,000 cycles, LiFePO4 lands near $0.12 per usable kWh-cycle versus ~$0.50 for lead-acid. Use the cost-per-kWh calculator to price your system.
Tell us your country, inverter and the loads you must keep on — we'll size a HomeWall or HomeStack system and quote distributor or OEM pricing.
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