When deadly wildfires tinted Western skies a Martian hue this week, homeowners with their own rooftop solar systems were able to tell with great precision just how much useful sunlight reached them through the gloom: next to none. Wednesday was “the worst generation day, ever,” said Mary Holstege, a retired software engineer in Cupertino, California, who went solar a year ago. Her system, which puts out 40 kilowatt-hours a day in the summer, barely dribbled out 1.65 — maybe enough to dry a load of laundry. Others fared worse. Bentham Paulos, an energy policy consultant in Berkeley, called the solar power system he’s had for 10 years “extremely predictable every single day, except this week.” On Wednesday he peaked at about 12 watts, or enough to light one LED bulb, “and it went away,” he said. The solar blackouts highlight […]