Simple ROI, payback, IRR and NPV from year-by-year cash flows. All preset values are invented. A design aid, not financial advice. Decimal commas are accepted.
Cash paid out, all years (USD)-
Net gain (USD)-
Simple ROI on all cash paid out-
ROI on year-0 cash only-
ROI divided by years-
ROI compounded per year-
Simple payback (years)-
IRR over horizon-
NPV at discount rate (USD)-
Model: year-t saving = output x (share used x import rate + exported share x export rate). Output falls by the degradation rate and the import rate rises by the escalation rate from year 2. Flows are at year end; year 0 holds the cash paid up front. Net gain = all inflows minus all cash paid out (O&M, replacement, loan payments). Simple ROI = net gain divided by all cash paid out. Loan: level annual payments. No tax. ROI compounded = (1 + ROI)^(1/years) - 1.