Free Solar Pump Sizing Calculator
Design your off-grid solar water pumping system in minutes. Calculate flow rate, Total Dynamic Head (TDH), pump power, and PV array size for irrigation, livestock watering, or select a pump by entering Q and Head directly. Results include real manufacturer performance curves and one-click product recommendations.
Location & Climate
How the Solar Pump Calculator Works
Our solar pump sizing tool follows a four-step engineering workflow: estimate daily water demand → compute TDH using the Hazen-Williams friction formula → match your operating point against stored pump H-Q curves → size the PV array by dividing shaft power by Peak Sun Hours with derating.
Irrigation Sizing
Calculate daily water demand for drip or sprinkler irrigation based on crop type, area, and climate zone.
Livestock Watering
Determine pump flow and head requirements for cattle, goat, sheep, and poultry watering systems.
Direct Pump Selection
Enter flow rate (Q) and Total Dynamic Head (TDH) directly to find matching solar pumps from our database.
Real Pump Curves
Results are powered by manufacturer H-Q and η-Q performance curves — not rough estimates.
Key Engineering Formulas
Pump Shaft Power
Ppump = Q × H / (367.2 × η)
Q = flow rate (m³/h), H = Total Dynamic Head (m), η = pump efficiency (decimal)
Friction Loss — Hazen-Williams
hf = 10.67 × L × Q1.852 / (C1.852 × D4.87)
L = pipe length (m), C = roughness coefficient, D = internal diameter (m)
Solar Array Sizing
Psolar = Ppump / (PSH × ηmotor × ηctrl × fderate)
PSH = Peak Sun Hours, fderate covers temperature, dust, and wiring losses
Frequently Asked Questions
- How does the solar pump sizing calculator work?
- You enter your water requirements (crop area or livestock count), borehole depth, pipe length, and location. The tool computes Total Dynamic Head (TDH) using the Hazen-Williams equation, then matches your operating point against real pump performance curves stored in our database to recommend suitable solar water pumps.
- What is Total Dynamic Head (TDH)?
- TDH is the total pressure a pump must overcome. It equals the sum of static head (vertical lift from water level to discharge point), friction losses in the pipe, and any additional pressure requirements. Our calculator uses the Hazen-Williams formula to estimate friction losses automatically.
- How is pump power calculated?
- Pump shaft power is calculated as P = Q × H / (367.2 × η), where Q is flow rate in m³/h, H is Total Dynamic Head in metres, and η is pump efficiency (decimal). The solar array is then sized by dividing pump power by Peak Sun Hours (PSH) and applying derating factors.
- Is this tool free to use?
- Yes — the solar pump sizing calculator is 100% free. No sign-up required. You get instant pump recommendations, performance curves, and PV array sizing at no cost.
- Can I use this for off-grid solar water pumping projects in Africa?
- Absolutely. The tool includes pre-loaded solar irradiance data for regions across Africa, the Middle East, and Asia, making it ideal for off-grid irrigation and livestock watering projects in these areas.