Hi Alex,
SAM's Third Party / Host Developer model assumes that the host sells all of the power generated by the system to the developer at an agreed-upon power prices (PPA price). The developer builds, owns, and operates the system and benefits from all incentives and tax credits. The host uses the power to reduce their electricity bill. The project is only economically viable to the host if the electricity bill savings are greater than the cost of purchasing electricity. The "host indifference point" is the PPA price at which the cost of purchasing power is the same as the value of the electricity bill savings.
I can't think of a way to force SAM to only consider purchases for self consumption. You could use the time series "Electricity from grid" output data to calculate that cost.
If you have a financial model implemented in Excel, you could write an LK script to calculate the cost in SAM and automatically export the data to Excel.
LK is SAM's scripting language
, which you can use to set the value of inputs, run simulations, export data, and for Windows versions of SAM, interact with an Excel workbook.
Best regards,
Paul.