Engineering selection guide
How to Choose a Solar Water Pump for Irrigation
Size a solar irrigation pump from daily water demand, total dynamic head and the available solar window. Then check the pump curve, controller and PV array as one system—not from motor power or a maximum-flow number alone.
A practical selection sequence
1. Calculate daily demand and target flow
Estimate irrigation, livestock or storage-tank demand in cubic metres per day. Divide by realistic pumping hours during the weakest design-season sunlight, allowing for weather and operating margin. For example, 120 m³/day over six useful pumping hours calls for roughly 20 m³/h at the actual duty head. This is a starting flow target, not a pump guarantee.
2. Calculate total dynamic head (TDH)
For a borehole, measure the dynamic water level while pumping, then add elevation to the delivery point, pressure needed at irrigation equipment, and pipe/valve friction at target flow. Convert pressure to metres of water where needed: approximately 10 m of head per bar for water. Use the lowest expected dynamic water level, not just the static level. Pipe diameter and distance can materially change friction loss.
3. Read flow and head on the same curve
Ask for the exact model's flow–head curve and find the point where it meets your target flow and TDH. A model code such as JBD52-30-300-3000 indicates a listed maximum flow of 52 m³/h, maximum head of 30 m, 300 V and 3000 W; maximum flow and maximum head are separate endpoints, never 52 m³/h at 30 m simultaneously. If the duty point is not on the curve, shortlist another model.
4. Choose deep-well or surface; DC or AC/DC
A deep-well submersible unit fits a borehole when its outside diameter, cooling and installation depth are suitable. A surface pump needs adequate flooded suction or a verified suction arrangement. DC-only systems use the controller's approved DC input; AC/DC systems can also use a compatible AC source. Confirm the exact model's controller and power option rather than assuming every series supports both.
5. Match the PV array to the controller
As a preliminary energy allowance, some projects start near 1.5 times the pump's rated watts in nominal panel capacity, but the final design must satisfy the controller's operating-voltage range, maximum open-circuit voltage, current and string configuration at local temperature extremes. For a 3000 W pump, 4500 W is a preliminary array target; four 1000 W panels total only 4000 W, so they do not meet that target. Series wiring raises voltage, not wattage.
6. Check installation and protections
Specify borehole diameter, cable length, pipe size, water quality, dry-run protection, tank-level control and available sunlight. Confirm sand tolerance and the required accessories on the actual pump/controller package. A tank can buffer variable solar production, but its volume should be sized to the customer's demand profile.
Worked starting point: 120 m³/day irrigation
A farm needs 120 m³/day and plans for six productive solar pumping hours, giving a first-pass target of 20 m³/h. If the pumping water level and delivery elevation total 18 m, irrigation pressure adds 8 m, and estimated friction adds 4 m, the requested duty is about 20 m³/h at 30 m TDH (approximately 88 US gpm at 98 ft). Send that paired duty point—not just 20 m³/h or 30 m—to obtain a model curve and array proposal. The figures are illustrative and must be verified on site.
Frequently asked questions
Can I select a pump from maximum flow and maximum head?
No. These are separate curve endpoints. The pump must deliver your required flow at your calculated total dynamic head on the same performance curve.
How many panels does a 3 kW solar pump need?
There is no universal panel count. A 4.5 kW nominal array is one preliminary sizing allowance for a 3 kW pump; panel wattage, controller voltage and current limits, climate and wiring determine the final number and arrangement.
When should I choose AC/DC?
Consider an AC/DC-capable package when you need a compatible grid or generator backup. Verify the exact pump/controller model and supply specifications before ordering.
Engineering background
These references explain general pump-selection principles; they do not certify a JIABO product or replace its current datasheet.
Confirm all final selections against the exact model’s latest performance curve, material specification and installation instructions.