Rolling outages make sense if you think about it. In Extreme weather, the demand for electricity exceeds the capability of the power company's generating capacity. Should they just leave everything as is then you get "brown outs", where the voltage and amperage drops. If this last for an extended period, it can damage appliances and electronics in your home. If it drops low enough, the entire grid goes out. So, rather than cause damage or lose the entire grid, they will shut down substations to keep the levels up. then next year, they ask for a price increase to build more generating power!