Water Pump Inputs
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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Design a solar-powered well pump for home water supply
This section explains how the Solar Water Pump Calculator works, including formulas, assumptions, and engineering principles used in system sizing.
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).
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%).
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).
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.
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.