Why is system output for year 1 shown as 100% or maybe a better question is How do I adjust the model so that year 1 output is either zero - during construction for larger projects or at a percentage that I input for smaller projects that may finish inside of the first year.
SAM assumes that the project begins operation in Year 1: The system starts generating electricity on January 1, and the project sells electricity and pays operating costs tarting in that year. The PPA financial models (Utility IPP, Single Owner, etc.) have a set of inputs on the Financing page to model construction financing costs. You can specify a construction period there for up to five construction loans. SAM calculates the construction financing cost and adds it to the project cost in Year 1. I think you should use hose inputs to account for your pre-commissioning costs.
That said, It is possible to adjust the system output on a year-by-year basis using the "Percent of annual output" variable on the Performance Adjustment page. Click the blue and grey button next to the variable, click Edit, and in the table of values enter a percentage for each year. If you enter a zero in the first row and 100% in the remaining rows, SAM will model the year 1 output as zero kWh. (See help topic for the Performance Adjustment page for more instructions on working with the annual schedule of values.)
This approach may result in a cash flow that works for your anlaysis, but will affect other metrics that SAM reports such as capacity factor and others that are Year 1 values.
Best regards,
Paul.