Can I run my air conditioner off solar during a blackout?

Grid connected inverters are required to disconnect when the grid goes down, so they cannot energise lines that workers may be repairing. That applies to batteries as well unless the installation includes the extra equipment that isolates the house from the grid and forms its own supply.

What backup actually requires

• A battery and inverter combination that supports backup operation. Not all do, and this is a purchase decision rather than a setting.
• A changeover or islanding device that disconnects the property from the network before forming a supply.
• A dedicated backup subcircuit, because most systems back up selected circuits rather than the whole house.
• Correct sizing, since a battery that comfortably runs a fridge and lights may not start a ducted air conditioner.

Choosing what to back up

The usual choices are the fridge, lighting, internet and a few power points, which is what keeps a household functional and lasts a long time on a typical battery. Air conditioning is the opposite: it has a high starting surge and a heavy continuous draw, so backing it up usually means a larger and more expensive system. Deciding this at quoting stage is much cheaper than adding it later, because the switchboard work is the awkward part.