This tools gives a financial assesment of solar photovoltaic projects.

financial evaluation of Solar PV system
Parameters taken into account for economic evaluation of PV installation investment :

     - Site Location
     - Orientation and inclination of solar photovoltaic generator
     - Guaranteed return of photovoltaic solar generator
     - Indexing in tariff electric kWh produced
     - Fiscal situation of the client (net of tax credits)
     - Aids & Grants
     - Products suitable financing

Exemple of financial analysis on PVCALC website. 
PVCalc allows you to calculate the ROI of PV solar energy projects. The results are presented graphically, divided into four sub-categories.
You can manage several  scenario analyses with respect to
1. leverage,
2. radiation and panel price,
3. inflation .

Go to Pvcalc.org website




See also professional photovoltaic softwares that include financial analysis of PV projects.