Solar models are careful about irradiance, soiling, and degradation. They are often careless about the hours the grid will not take the power. Curtailment is not a line in the loss stack. It is a decision by someone who does not sit in the financial model.

Separate contracted volume from delivered volume

If the offtake pays only for energy delivered, every curtailed hour is lost revenue. If it pays for deemed or available energy, the contract is doing the work the resource study cannot. Read which one you have before you apply a production estimate.

Where the risk actually sits

Congestion, overbuild in the same node, and priority rules for other generators all show up as curtailment. A project with a beautiful resource and a crowded node can under-earn a duller site with firm access. Price the node, not only the sun.

Put a curtailment case next to the base case. If the return only works when the grid always says yes, the return is not underwritten.