Both Stanford University Hospital and Lucile Packard Children's Hospital were operating on emergency power Wednesday.
Surgeries in progress when the outage hit continued under emergency power, but non-emergency surgeries were postponed, the hospitals said in a statement.
The emergency department remained open "only for the most urgent cases," and the hospital urged people not to come to the hospital unless it is truly necessary.
Palo Alto's 17 public school campuses remained open and were managing the outage school-by-school.
"Teachers are still teaching," said Walter Hays School Office Manager Ruta Henard.
Without power, the computer-based "smartboards" in the district's classrooms became useless.
Some teachers resorted to the remaining "whiteboards" and colored markers, now considered out of date.
"We're back to a simpler time," said Walter Hays office assistant Gaynor Brown. "It's actually very, very calm."
Children were excited by the thought of a day without power, but teachers improvised.
At Walter Hays, the "hot lunch service" was still hot, thanks to the fact that it was, as usually, prepared in a gas-powered kitchen at JLS Middle School. Choices were cheeseburgers and Caesar Salad.
At Jordan Middle School, Assistant Principal Christine Wang said teachers were taking advantage of the natural light from large windows in most classrooms. In the darkened main office, teacher Hal Roach rigged up a single, battery-powered light.
At Gunn High School, some classes reportedly were moved outside.