> Installed capacity is installed capacity. It does not "fluctuate" throughout the year.
7 days ago I had a new array of 12kW of solar panels plugged into the grid.
So far I've had one properly sunny day - that generated about 53kwH.
Because we're in autumn, two weeks away from the equinox, I know that this is going to be 'about average', but through the year there'll be seasonal variations.
In 3 months from now, f.e., at the winter solstice, I may hit 30kwH on a clear day, but averaging probably 20kwH per day. Some days, if it's raining, or very overcast, of course, it'll be less.
Thinking that my 'installed capacity' is the maximum available in the middle of summer, on a cloudless day, would be an unhelpful way to think of it. Rather, I'd consider 'over the year, I'll get x amount of power generated', and then divide that by 365 for an average daily amount.
Similar to how the ERCOT team has said 'over the year, our wind turbines will generate x amount of power' - but they've also gone into seasonal sub-divisions.
So, if you want to make a point about wind turbines not fulfilling the theoretical maximum output in the wrong half of the year while half the fleet is frozen, I can see why you'd want to assume it's mid-summer all year around.
