[throwaway829]

And it's always a Sunday when virtually no work is being done, on a day with perfect weather so no AC or Heating and most people have no need for indoor lighting. For most people a black out during this time would go unnoticed.

[samcheng]

Well, it's California, so the perfect weather is more common than you might think!

[cinntaile]

You're reading too much into this, the day isn't as important as the time of day.

[throwaway829]

I imagine you're referring to the importance of good solar conditions for the production of electricity and I agree that's vital. However these articles give false hope by matching peak solar production to the lowest possible consumption period which is always on the weekends with 70 degree weather. You have close to zero commercial machinery, zero need for climate control, zero lighting (people are either outside or use natural light).

[tamaharbor]

Season is also important. At many electric utilities in the US, system light load is typically during a weekend in the Spring.