Failures on the mains energy system can be expected to become more frequent in the years ahead as the population increases and the effects of climate change become increasingly obvious. These occurrences will have minimal impact on your life if you have a solar power system, and even less of an impact if you have a battery backed solar power system.
Solar panels allow you to convert sunlight into electricity. Batteries allow you to store the electricity your solar panels generate. A properly set up battery backed system will be safe and economical. The biggest advantage is that in an emergency, your home will not be one of those without power.