This is incorrect. It is not for a few minutes!

We are way way past that at this point. The renewable generation meeting the total demand is over most of the day. Because of solar PV, the cheapest generation now, the daytime electricity supply is actually more than we need in California. Solar farms (and also wind farms)get curtailed here due to supplying more than the grid can take at times; this is usually for several hours.

Source; reporter covering solar news through interviews with grid operators, solar developers and policymakers since 2008