The International Energy Agency has under-forecasted renewable growth for something like 20 of the last 20 years. I don't think it's a given that a model is overly optimistic.
(I realize that this article is about a different, US DOE forecast, I'm just saying that they are working from a model that has assumptions in it and it has proven difficult to model this space)
Their recent adjusts are not little tweaks...
https://www.weforum.org/agenda/2021/05/exceptional-new-norma...
(I realize that this article is about a different, US DOE forecast, I'm just saying that they are working from a model that has assumptions in it and it has proven difficult to model this space)