Solar Water Pump System

Design a solar-powered well pump for home water supply

Water Pump Inputs

Daily water need (liters)

Pumping hours/day

Total head (meters)

Pump efficiency (%)

System voltage

Peak sun hours

System losses (%)

Battery backup (days)

System Result

Pump Power

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Daily Energy

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Solar PV Size

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Battery Bank

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Flow Rate

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Summary

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Bill of Materials

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Solar Water Pump Design Guide (EEAT Supporting Information)

This section explains how the Solar Water Pump Calculator works, including formulas, assumptions, and engineering principles used in system sizing.

🔬 1. Engineering Basis (Expertise)

This calculator uses standard hydraulic and photovoltaic sizing principles commonly applied in off-grid solar pumping systems. The pump power is estimated using the hydraulic energy equation:

P = (ρ × g × H × Q) / efficiency

Where: ρ = water density (1000 kg/m³), g = gravity (9.81 m/s²), H = total head (meters), Q = flow rate (m³/s).

⚡ 2. Solar Sizing Method

Solar PV size is calculated based on daily energy demand divided by peak sun hours and system losses:

PV (kWp) = Energy (kWh/day) ÷ (PSH × efficiency factor)

This ensures the system can reliably run the pump under real-world weather and conversion losses (typically 15–25%).

🔋 3. Battery Design Logic

Battery storage is sized for autonomy days to support pumping during cloudy conditions:

Battery Capacity (kWh) = Daily Energy × Autonomy Days

Voltage and amp-hour conversion is based on standard DC battery banking configurations (12V modules in series/parallel).

🌞 4. Assumptions & Limitations

Constant sunlight (peak sun hours average)
No seasonal extreme variation included
Pump efficiency is user-defined (typically 50–70%)
Does not include pipe friction losses in detail

🧠 5. Practical Engineering Notes

In real installations, pump selection should also consider: motor type (DC vs AC), pipe diameter, elevation variation, and water source depth (borehole or surface tank). Oversizing PV by 10–30% is common in tropical climates to improve reliability.

🛡️ 6. Trust & Use Disclaimer

This tool is designed for educational and preliminary system planning only. Final system design should be validated by a qualified solar or electrical engineer before installation.