PV-yield simulation in Costa Rica

Hey,

as part of my investigations I want t use the RN-program for a yield simulation in Costa Rica. I intend to apply three scenarios: optimistic(O), realistic ®, pessimistic§.

Does anybody has reommendations for correction factors of the by RN simulated yield?
I would be glad to hear a justification maby on the base of the published paper on the RN-program.

Best wishes,
Kevin