Some homes are at risk of losing power today as a heat wave blankets the Bay Area. PG&E customers in Napa and Solano counties were alerted yesterday to prepare for planned outages. The utility says this is one way to prevent its equipment from sparking wildfires in the area. An excessive heat warning starts this morning for those living inland where temperatures could soar to 110-degrees. Spots closer to the bay are bracing for 90s.