As the American electric grid becomes less dependable, a growing number of businesses and homeowners are buying their own power systems to protect themselves from being left in the dark.
Twenty years ago, only 0.57% of U.S. homes worth $150,000 or more had installed backup generators, mainly along hurricane-prone coastlines, according to backup-power provider Generac Holdings Inc. Now the number is 5.75%, a 10-fold increase.