This file is an application of a Focus on Energy spreadsheet developed to take into account several variables that affect the residential or commercial solar investor when considering the cash flow and the return on investment over time for hypothetical solar projects. 

Look at the bottom of the first page for the timeline / cash flow / time for return on investment, as well as the IRR (internal rate of return).

This is by no means meant to replace professional accounting or legal advice on this type of investment.  Consult your own tax attorney or accountant for your specific circumstances.