Hydropower potential
& project returns
Screen river potential, investment returns and Senior financing. The initial figures are examples; replace them with your project data.
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Hydropower potential
Steady-mean estimate at the entered river flow
Flow after environmental allowance = max(0, mean river flow − environmental flow).
Power (MW) = 0.00981 × net head × flow after allowance × efficiency / 100.
The steady-mean estimate holds the mean river flow constant for 8 760 hours. A gauging point or your monthly flows supply the seasonal shape. Finance uses expected annual GWh, distributed after environmental flow and the turbine limit.
Choose a point and reference scenario, then select Adjust profiles.
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P rows are out of order: drier P should give less energy.
Paste a table or enter flows across the grid, then assign P and select the row used in calculations.
Monthly river flow by scenario
Project economics
Choose annual generation manually, from capacity or from hydrology
In Manual mode, annual generation and the last edited capacity field determine the third value. From capacity, installed MW and capacity factor determine annual generation. From hydrology, applied flows and installed MW determine annual generation and capacity factor. Grant and OPEX inputs remain linked; OPEX % uses gross CAPEX. For small hydro, IRENA cites 1–6% of CAPEX per year; this range is only a reference. You can enter any non-negative percentage.
IRR before grant invests gross CAPEX at Year 0 and excludes grant income from tax. NPV and IRR after grant invest net CAPEX (gross CAPEX less grant) at Year 0; the grant is recognized as taxable income evenly over the operating life. Generation begins after the COD delay. Price and OPEX escalate once per operating year. Gross CAPEX is depreciated evenly from COD through the operating life in both cases. Tax losses carry forward without expiry in this simplified model. Annual CIT reflects carried tax losses; its modeled monthly cash-flow allocation follows positive monthly taxable income after depreciation, grant income and financing interest where applicable. Actual CIT payment dates depend on local law. Returns use after-tax unlevered cash flows and an effective annual discount rate. Discounted payback starts at Year 0; profitability index equals the present value of operating cash flow after grant divided by net CAPEX. Validate the applicable tax treatment for your jurisdiction; degradation and other inflation are excluded.
LCOE = [gross CAPEX at Year 0 + Σ(monthly OPEX / discount factor)] / Σ(monthly generation / discount factor). This weighting compares costs and output at a common date; it does not change the physical kWh generated. The calculation uses the entered annual discount rate, COD delay, seasonal generation profile and OPEX escalation. Grants, CIT and financing do not change this cost measure; LCOE is undefined when generation is zero.
INVESTMENT
ELECTRICITY PRICE
COSTS, TAX & LIFE
First full operating year
Price is fixed within each operating year; a selected river profile shapes monthly generation and revenue| Period | Generation | Revenue | Operating cost | Modeled CIT | Cash flow after CIT |
|---|---|---|---|---|---|
| Per month | — | — | — | — | — |
| Per year | — | — | — | — | — |
Monthly detail · first operating year
| Month | River flow · m³/s | Turbine flow · m³/s | Generation · GWh | Revenue · €m | OPEX · €m | Modeled CIT · €m | Cash flow · €m |
|---|
Financing & equity returns
Senior interest capitalised until COD; level monthly payments thereafter
Edit Senior debt or its share of net CAPEX in manual mode. Sizing uses the lowest annual after-CIT cash available for debt service during the tenor, including the modeled interest tax shield.
Senior is drawn at Year 0. Interest accrues monthly at the annual rate / 12 and is capitalised until COD; equal monthly payments begin at COD. Operating-period interest reduces taxable income. Displayed DSCR is the minimum annual after-CIT cash available for debt service divided by annual debt service during repayment. Equity returns include modeled CIT and debt payments. Capitalised pre-COD interest is excluded from the tax depreciation base; interest deductibility limits, fees, reserves, balloons and refinancing are excluded.
Seasonal liquidity
Dry-year stress test
P rows are out of order: drier P should give less energy.
| Scenario | Annual generation · GWh | NPV after grant · €m | IRR after grant · % | Min annual DSCR · × |
|---|
Project cash flow after grant and CIT
Two charts on the same reporting years: annual revenue above, cumulative cash flow below
Annual revenue
€m / year · OPEX and the balance after OPEX
Annual profit & loss
Calendar years from Year 0 · €m