That is all the capacity added together before de-rating. Capacity is de-rated based on how likely it is to produce during a system load peak. So a nuclear plan

That is all the capacity added together before de-rating. Capacity is de-rated based on how likely it is to produce during a system load peak. So a nuclear plant might be counted as 75% of nameplate to account for outage risk. Renewables are de-rated a lot and by how much changes over time as they make up a larger share of the connected capacity. California de-rates solar by less than, say, the UK since Cali has a lot of air conditioning load which is coincident with insolation whereas summer days are the low-load periods in the UK. The capacity before de-rating > capacity after de-rating > highest anticipated load > actual load on a normal day.