Capacity is the ability to produce energy and with renewables that number is very different than with fossil fuels or nukes.

Renewables never reach capacity, well your solar might for a peak moment, but then it will drop as the sun drops.

For example - you have a 200 MW wind farm, you might only be able to produce 10MW at that moment. The capacity is 200MW, the generation is 10.

Also the 3rd was a Sunday in spring - no office workers, less demand, not a heating or cooling day in a lot of California, ie a lower energy day than say a week day in summer where the temp is 105 in the Central Valley.