PG&E began cutting off power to more than 700,000 households and businesses across northern and central California in rolling blackouts to prevent wildfires. The utility said it could take up to five days to restore power. Photo: Getty Millions of Californians could lose power in coming days, the state’s grid operator warned Monday, as it continues to struggle with inadequate electricity supplies as many people have been forced indoors to ride out a crippling heat wave during the coronavirus pandemic. The rolling blackouts across California serve as a cautionary tale as states across the country increase renewable energy and reduce their reliance on fossil fuels that can generate round-the-clock power but contribute to climate change. …