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 gauging point, set the flow basis and calculation profile, 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.
Project NPV and IRR use CAPEX at its payment dates. Before-grant IRR uses gross CAPEX and excludes grant income from tax; after-grant returns subtract the grant proportionally from payments. The grant is taxable income evenly over operating life. Gross CAPEX is depreciated by the selected classes from COD. Tax losses carry forward; annual CIT is allocated to months using taxable income. Returns use monthly after-tax cash flows and an effective annual discount rate. Profitability index uses the present value of net CAPEX. Actual tax payment dates depend on local law.
LCOE = [discounted gross CAPEX payments + discounted monthly OPEX] / discounted monthly generation. Payments and production are compared at the same date using the annual discount rate. Grants, CIT and financing do not change LCOE; it is undefined when generation is zero.
INVESTMENT
To enter CAPEX shares, set Construction period above to at least 0.5 years. At 0 years, CAPEX is paid upfront.
Share of CAPEX paid in each construction half-year, %
ELECTRICITY PRICE
COSTS, TAX & LIFE
TAX DEPRECIATION
MWIP screening: 12.5% development (5 years), 66.5% civil works (20 years), 21% equipment (25 years).
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; debt service follows the selected profile
Edit Senior debt or its share of net CAPEX in manual mode. Sizing uses annual after-tax cash for debt service and the modeled interest tax shield; sculpted payments follow each year's cash flow.
Senior is drawn in proportion to net CAPEX payments; interest capitalises monthly on each draw until COD. During a grace period only interest is paid, followed by the selected repayment profile. Operating interest reduces taxable income. DSCR uses annual after-CIT cash and scheduled payments. The loan fee is paid by equity with the first draw and does not affect project returns or taxable profit. Interest deductibility limits, reserves, balloons and refinancing are excluded.
Required electricity price at COD
Price for NPV = 0 is the minimum that earns the required project return. Price for target debt is the minimum at which the bank can lend the planned share at the target DSCR. The required price is the higher of the two.
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