Quick Answer
A generator is not always necessary if you have a well-designed battery backup system, but it can be useful for providing supplemental power or covering long outages.
Understanding Your Power Needs
When deciding whether to use a generator with a battery backup system, consider the size and power requirements of your home. A well-designed battery bank and inverter can handle the average daily load, but may struggle with long outages or high-power appliances like electric water heaters or furnaces. For example, a 12-kilowatt battery bank can handle the average load of a 1,500-square-foot home, but may struggle with a 5-kilowatt electric water heater.
Generator Options for Supplemental Power
If you have a battery backup system but still want the option of a generator for supplemental power or long outages, consider a whole-house generator or a portable generator. A whole-house generator is a more expensive option that can automatically switch between battery power and generator power, while a portable generator can be moved around the yard to provide power to specific appliances.
Choosing the Right Generator Size
When selecting a generator, consider the total power requirements of your home, including the battery bank and any high-power appliances. A general rule of thumb is to choose a generator that is 10-20% larger than the total power requirements of your home. For example, if your home requires 10 kilowatts of power, choose a 11-12 kilowatt generator to account for startup loads and efficiency losses.
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