PG&E CEO Bill Johnson warned California regulators that power shutdowns to prevent wildfires could be a fact of life for Bay Area residents for up to 10 years as the utility works on upgrading its operations. Johnson delivered the bad news, along with an apology for how things were handled in this month’s power shutdown, at a California Public Utilities Commission hearing Friday, The Wall Street Journal reported. During this month’s so-called public safety power shutoffs, PG&E (NYSE: PCG) saw…