What a production cost model actually does
The primer. What the solver is minimising, what the constraints represent physically, and why the answer is a schedule rather than a price.
A production cost model is a cost minimiser with a calendar. That is the whole idea. You give it a set of generators, a set of fuel prices, a demand shape, and a network, and it works out the cheapest way to serve that demand hour by hour without violating anything physical. The prices everyone quotes are a by-product. They fall out of the solution; they are not what the model was asked for.
That distinction explains most of the confusion around these tools. When someone says the model "forecast" a price of sixty-five dollars, what actually happened is that the model scheduled a unit whose marginal cost was sixty-five dollars to serve the last megawatt in that hour, in that location. Change anything that alters which unit sits at the margin — a fuel curve, an outage, a new interconnection, a transmission limit that binds — and the price moves without the model having any opinion about prices at all.
So the honest description of the output is a dispatch schedule with prices attached. Every question worth asking about a forecast is really a question about the schedule: which units were available, what they cost to run, what the network let them do, and what the model believed demand would be.