Calculator Inputs
The form uses a responsive grid: three columns on large screens, two on smaller screens, and one on mobile.
Example Data Table
These sample cases are illustrative and help compare different field conditions.
| Scenario | Water Demand (L/day) | Total Head (m) | PSH | Pump Eff. (%) | Recommended Array (kW) |
|---|---|---|---|---|---|
| Small livestock point | 6,000 | 24 | 5.8 | 45 | 0.58 |
| Village storage tank | 20,000 | 38 | 5.5 | 50 | 1.95 |
| Drip irrigation block | 35,000 | 52 | 5.2 | 55 | 4.07 |
| High-lift hill supply | 18,000 | 70 | 4.8 | 52 | 3.58 |
Formula Used
1) Adjusted water demandAdjusted Demand = Daily Demand × Seasonal Multiplier
2) Required pumping flowQ = Adjusted Demand / (1000 × Peak Sun Hours × 3600)
3) Pipe friction headhf = 10.67 × L × Q1.852 / (C1.852 × d4.871)
4) Total dynamic headTDH = Static Level + Drawdown + Delivery Height + Friction + Miscellaneous Losses
5) Hydraulic powerPh = ρ × g × Q × TDH
6) Electrical pump inputPe = Ph / (ηpump × ηmotor)
7) Recommended array sizeArray Power = Pe × (1 + Safety Factor) / PV Derating
8) Suggested storage volumeTank Size = Adjusted Demand × Storage Days
Use SI units: flow in m³/s, pipe diameter in meters, head in meters, and power in watts.
How to Use This Calculator
- Enter the daily water demand in liters.
- Apply a seasonal multiplier when peak demand is higher.
- Input static level, drawdown, and delivery height carefully.
- Enter pipe length, internal diameter, and Hazen-Williams C value.
- Set realistic pump efficiency, controller efficiency, and PV derating.
- Click the calculate button to generate the result summary and graph.
- Review the recommended array size, tank volume, flow rate, and current.
- Export the result as CSV or PDF for documentation.
Frequently Asked Questions
1) What are peak sun hours?
Peak sun hours represent equivalent full-sun energy received daily. They are not daylight hours. Use conservative monthly or seasonal values for reliable pump sizing.
2) Should I include seasonal demand growth?
Yes. Seasonal demand or a separate safety margin can cover crop peaks, hotter months, aging panels, and dirt losses. Conservative inputs reduce undersizing risk.
3) Why does pipe diameter matter so much?
Pipe friction depends on flow, length, diameter, and roughness. Longer pipes and smaller diameters increase head loss, which raises required pump power and array size.
4) What is total dynamic head?
Total dynamic head combines vertical lift and losses. A higher flow rate usually needs more power. Both values must match the pump curve for practical equipment selection.
5) Is this enough to select the final pump?
No. This calculator provides engineering estimates for preselection. Final equipment choice should be checked against manufacturer pump curves, controller limits, voltage windows, and site tests.
6) How large should the storage tank be?
The storage tank should cover daily demand plus reserve days. More storage can reduce pump cycling and help during cloudy periods, maintenance, or temporary demand spikes.
7) What happens if efficiency values are too low?
Very low efficiency values sharply increase electrical power and array size. Use realistic pump and controller efficiencies from product data, not best-case marketing numbers.
8) Can I use this for fluids other than clean water?
Yes, but water density and viscosity can change performance. For unusual liquids, very cold water, or slurry service, consult manufacturer data and detailed hydraulic design.