How to use the Water Pump Solar Sizing Calculator
The Formula
Off-grid and agricultural pumps run on predictable daily energy. Undersized arrays leave tanks empty; oversized arrays waste capex. This tool links pump load, lift, and local sun hours to kWp and panel count.
Practical Example
Daily Wh = pump W × run hours × (1 + 0.6% × head in meters). kWp = daily kWh ÷ (peak sun hours × ~80% system efficiency). Panel count = ceil(kWp × 1,000 ÷ module watts). Add 20–30% margin for cloudy days if you need battery backup.