bornstein points to the massive upgrades the state has done to its power grid in recent years to helpuce the chance of flood alerts, which asked californians to reduce their energy use and the biggest change we've seen over the last few years is a massive installation of batteries. >> if you go back four years, california had essentially no batteries to store power, bornstein says. >> given the updates, he doesn't expect mass power outages like we've seen in the past. this time around, he believes, given the upcoming holiday and weekend, wednesday will likely be the day the grid is most stressed. >> we still have people going to work, and it's going to be the second day of the heat wave, so buildings are going to be hotter and not have had a chance to cool down overnight. >> now, as of tonight, the largest power outage is being reported here in the bay area are in the east bay. in addition to concord cities such as dublin, san ramon and danville also have no electricity due to the weather. i'm live in the studio tonight. tim johns, abc seven news. all right, tim, thank you. >> we are