Enter Hydro Project Inputs
Example Data Table
| Scenario | Flow (m³/s) | Gross Head (m) | Net Head (m) | Total Efficiency (%) | Electrical Output (kW) | Annual Energy (MWh) |
|---|---|---|---|---|---|---|
| Run-of-river small plant | 12 | 35 | 33 | 82 | 3,185.50 | 15,880.00 |
| Medium head plant | 28 | 72 | 68 | 85 | 15,874.39 | 76,420.00 |
| High head scheme | 9 | 180 | 172 | 88 | 13,378.18 | 70,260.00 |
| Micro hydro site | 0.95 | 24 | 22 | 74 | 151.77 | 690.00 |
Formula Used
1) Hydraulic power from flowing water
Phydraulic = ρ × g × Q × Hnet
Here, ρ is water density, g is gravitational acceleration, Q is flow rate, and Hnet is net head after subtracting losses.
2) Net head
Hnet = Hgross − Hloss
3) Combined efficiency
ηcombined = ηturbine × ηgenerator × ηtransformer × (1 − auxiliary losses)
4) Electrical power output
Pelectrical = Phydraulic × ηcombined
5) Annual energy estimate
Annual Energy = Pelectrical × 8760 × Capacity Factor × Availability
This screening method is ideal for early feasibility reviews, budget estimates, and turbine comparison studies.
How to Use This Calculator
Enter the available site flow and select the correct flow unit. Then enter gross head and estimated head loss using the same head unit.
Set realistic turbine, generator, and transformer efficiencies. Add auxiliary losses to reflect station service or other parasitic loads.
Use capacity factor and plant availability for energy forecasting. Capacity factor reflects how often the plant runs below rated power through the year.
Enter the number of generating units if you want per-unit output. Add a tariff if you also want a rough annual revenue estimate.
Press the calculate button. The result block appears above the form, shows key outputs, and includes CSV, PDF, and Plotly graph options.
Frequently Asked Questions
1. What is the difference between hydraulic power and electrical output?
Hydraulic power is the raw water power before machine losses. Electrical output is the usable delivered power after turbine, generator, transformer, and auxiliary losses are applied.
2. Why does net head matter more than gross head?
Gross head is the elevation difference. Net head is what remains after friction, penstock, and intake losses. The turbine can only convert the net head into useful power.
3. Should I use average flow or maximum flow?
Use the flow value that matches your design case. Average or dependable flow is better for realistic annual energy forecasting, while maximum flow is more useful for peak output checks.
4. Can this tool help size a turbine?
It gives a solid starting estimate for output and energy, which helps narrow turbine options. Final turbine sizing still needs flow duration data, cavitation checks, and manufacturer selection curves.
5. Why is annual energy lower than nameplate output?
Plants do not run at full rated output every hour. Capacity factor and availability reduce the theoretical maximum to reflect seasonal water changes, maintenance downtime, and operating constraints.
6. What values are typical for efficiency?
Large modern turbines often exceed 90%, generators are commonly 95% to 98%, and transformers are usually very high. Small systems may have noticeably lower total efficiency.
7. What does the power curve show?
The Plotly graph shows how electrical output changes as flow varies around your entered design point while net head and efficiency assumptions stay constant.
8. Is the revenue result a final financial forecast?
No. It is only a quick estimate based on annual energy and tariff. Real project revenue should also include curtailment, escalation, wheeling charges, outages, and contractual terms.