Solar and battery guides
Battery backup for ICE power outages
Start with what you want to keep working when the power goes out. A backup system is designed around those appliances, their combined power demand and the hours of cover you need.
Which appliances should stay on?
Common priorities are refrigerators, lights, a router and selected water pumps. Air conditioning, electric cooking and water heaters can require much more power. List the essentials first, then decide which larger loads belong on backup.
Inverter power in kW determines which loads can run together. Battery energy in kWh helps determine how long they can run. Motor starting demand, battery output limits and the chosen circuits must also be checked.
How long will the battery last?
For an illustration, assume 8 kWh is available to the appliances after the reserve and conversion losses. At an average load of 0.5 kW, that is about 16 hours; at 2 kW, about 4 hours. These are calculated examples, not measured project runtimes.
Actual runtime changes with the charge at the start of the outage, appliance cycling, battery condition and any solar production. Internet also depends on your provider keeping its network running.
Assumes 8 kWh reaches the appliances after reserve and losses, with no recharging. Calculated examples, not measured project runtimes.
Battery only or solar plus battery?
Battery-only backup charges from ICE while the grid is available and automatically supplies selected circuits during an outage. It is an option when outage protection comes first; it does not generate electricity.
Solar plus battery can supply daytime demand and recharge storage when sunlight is available. An appropriately configured backup system can use solar during an outage. Panels alone do not guarantee power when the grid fails.
What our Santiago project shows
The documented Santiago installation has a 10 kWh battery, a 12 kW inverter and 6.6 kWp of solar. The home includes pumps, refrigeration and other household loads. This does not mean every appliance runs together or that a 10 kWh battery covers every home overnight.
We review the electrical installation and essential loads before selecting equipment. If you want to add solar later, tell us at the design stage so the proposed system can support that plan.