Fleam,
It's Sunday.
Here is the California ISO chart
Tomorrow businesses will be adding to demand
Every Office building needs A/C
Today was Easy Day for PG&E
Tomorrow, demand may exceed supply
Outdoor temp 58 degrees F this pleasant midwinter afternoon.  But we did set an electric consumption record (for heating) during a cold spell in June.  Home AC is rare in NZ so winter electric consumption is still greater than summer.  The June cold spell was not exceptional but the recent housing boom has put people into bigger houses with greater heating demand.  All things otherwise being equal, heating 2000 sqft uses more energy than heating 1000 sqft.