Do not assume a battery provides backup. Ask for the exact equipment, circuits and operating limits included.
Name what must stay on
List the appliances you need during an interruption, such as refrigeration, communication or lighting. Their combined running and starting loads matter. Treat critical medical equipment as a separate requirement needing appropriate professional advice and a dependable backup plan.
Understand the installation
Backup operation may require compatible equipment, switching arrangements and dedicated circuits. Ask whether the system supports the whole home or only selected loads, whether switching is automatic and whether solar can recharge it while disconnected from the grid.
Balance reserve and everyday use
Energy kept in reserve for an outage cannot also be counted as fully available for routine savings. Ask how reserve settings work and how long your chosen loads might run. Runtime estimates should use usable capacity and realistic appliance consumption.
Calculate a realistic running time
As a calculation example, 4 kWh available for backup divided by a steady 0.5 kW load gives eight hours before allowing for conversion losses or other limits. A 2 kW load would use the same energy in two hours. Real appliances cycle on and off, so add up a realistic pattern rather than every nameplate rating. Then check starting surges separately from the energy budget.
Write down the outage sequence
Ask what happens when the grid fails, how the system switches, which circuits remain live and how normal operation returns. Include a failure overnight, a partly discharged battery and a loss of internet access in the discussion. These scenarios reveal practical differences hidden by a single “backup capable” label. Request a demonstration using the installer’s approved test procedure and keep the operating instructions with the handover documents.
Make everyday settings support the plan
A reserve that is too small may not cover the intended outage, while a larger reserve leaves less energy for daily use. Choose it around the appliances that matter to you. Check who can change the setting and what alerts appear when capacity is low. Plan how to charge essential communication devices and how household members will recognise a backup event without opening electrical equipment or improvising connections.
Your planning checklist
- Named circuits and appliances supported during an outage.
- Available backup energy and maximum output power.
- Automatic switching, restart and solar-recharging behaviour.
- An operating demonstration and accessible written instructions.
Common questions
Will the panels keep producing during a grid outage?
Only if the installation is designed to operate that way. A normal grid-connected solar system is not automatically an independent supply. Confirm whether the specified backup arrangement can run the solar inverter and recharge the battery.
Does whole-home backup mean every appliance can run together?
No. The output limit still applies, and some combinations may exceed it. Ask for an appliance-level explanation covering heavy loads such as cooking, vehicle charging and electric heating.