Type: |
Output Variable |
Units: |
% |
Symbol: |
ROI |
The Return on Investment (ROI) is the yearly cost savings relative to the initial investment. HOMER calculates the return on investment with the following equation:
where: |
|
|
|
Ci,ref |
= nominal annual cash flow for base (reference) system |
|
Ci |
= nominal annual cash flow for current system |
|
Rproj |
= project lifetime in years |
|
Ccap |
= capital cost of the current system |
|
Ccap,ref |
= capital cost of the base (reference) system |
In words, the ROI is the average yearly difference in nominal cash flows over the project lifetime divided by the difference in capital cost.
Note: The year nominal cash flows are available in the cash flow tab of the detailed results window. You can export the cashflow data by switching to "Table" with the radio buttons in the top left of the cash flow screen, and then use the "Export To:" drop down menu on the right to export the data.