Engineering selection guide

How to Size a Solar Submersible Pump for a Borehole

A solar borehole pump must match daily water demand, the pumping water level and delivery head—not just well depth or motor horsepower. Use these checks to shortlist a deep-well pump, controller and solar array.

Solar deep-well and borehole pumps →4-inch solar deep-well family →

Stainless-steel solar deep-well pump units on a JIABO factory assembly line — JIABO deep-well pump assembly. The image shows a product family, not the exact model for the worked example.

A practical selection sequence

1. Measure water demand and borehole yield

State the required water volume in m³/day and the design-season hours when solar pumping is expected. A first-pass target flow is daily volume divided by useful pumping hours, but it must not exceed the sustainable borehole yield from a pumping test. Include dry-season demand and any storage-tank buffer.

2. Use dynamic water level, not total well depth

Measure the water level while pumping at the proposed flow. Total dynamic head includes lift from that pumping level to the delivery point, required outlet pressure and pipe/friction losses. Static water level or drilled depth alone is insufficient; seasonal drawdown can change the duty.

3. Check fit, submergence and water quality

Give borehole internal diameter, casing and screen details, pump setting depth, minimum expected water level, sand content and cable run. The selected pump must physically fit, remain adequately submerged and meet the manufacturer's cooling and sand limits.

4. Match flow and head on one model curve

Compare the required flow at the calculated head with the current exact-model flow–head curve. Maximum flow and maximum head are separate endpoints; neither proves that the pump will meet both figures at once. Check the operating range, motor loading and available well yield.

5. Design the power and controls as a system

Confirm DC or AC/DC controller availability for the exact model, PV input-voltage window, cold-weather open-circuit voltage, current limit and panel-string arrangement. Include dry-run sensing, tank-level control, cable voltage drop and any compatible AC backup. Panel wattage by itself is not a complete design.

6. Request the installation package

Ask for the model curve, current bill of materials, controller data, dimensions, cable specification, lifting and non-return-valve instructions, and commissioning procedure. Local electrical and groundwater rules must be checked for the destination market.

Worked starting point: a borehole feeding a storage tank

Suppose demand is 36 m³/day over six productive pumping hours: the first-pass target is 6 m³/h. If the dynamic water level to outlet elevation is 46 m and estimated pipe loss is 9 m, the preliminary duty is 6 m³/h at about 55 m total head, before any required outlet pressure. This is a sizing example, not a JIABO model recommendation; confirm the pumping test, curve and site losses.

Frequently asked questions

Is a 100 m-deep well a 100 m-head pump duty?

Not necessarily. Use the pumping water level, delivery elevation, outlet pressure and friction loss. The pump setting depth also matters for submergence and cooling, but is not by itself the total head.

Can I choose a solar borehole pump by horsepower?

No. Horsepower narrows the electrical class; the required flow at total dynamic head and the exact curve determine hydraulic suitability.

Do I need batteries?

Not automatically. Many systems pump into water storage during sunlight, but the best storage and backup arrangement depends on the demand schedule and controller package.

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.