In a power outage, your system is designed to turn off. This allows utility company electricians to safely work with power lines. There are some new residential inverters that have a low capacity USB storage, in which you can plug an extension cord and power up some lights or low wattage appliances during a power outage.
The good thing is that power rarely gets interrupted here in Southern California. If your home is in an isolated or secluded area, then you might want to consider a generator or a battery back-up.