How to Choose a Solar Borehole Pump

A solar borehole pump is a big purchase, and the right one depends on your borehole, your tank and how much water you use. Before we recommend a pump, we always ask the same 7 questions. Answer them below, send them to us on WhatsApp, and our technical team will match you with the right pump, controller and panels.

The 7 questions we ask before recommending a pump

1. How deep is the borehole?

This is the total depth that was drilled. It tells us how deep the pump can be installed and how much cable and pipe you need. It is not the number used to size the pump. That number is the water level, below.

2. Where does your water level start?

This is the depth from the ground to the water surface in the borehole, and it's the most important number. The pump has to lift water from this level, so it sets most of the "head" (the total height the pump must push). If you have the driller's report, the water level (static level) is on it.

3. How high above the ground is your JoJo tank?

Add the height of the tank stand, or of the highest outlet the pump fills. Example: a 50m water level plus a 6m tank stand gives 56m before friction.

4. How far is the JoJo tank from the borehole?

Water loses pressure as it flows through pipe. A long pipe run to the tank adds friction, which works like extra height the pump has to overcome. Allow about 10% extra for short runs, and more for long ones.

5. What size is your JoJo tank, in litres?

A solar pump only runs in daylight. The tank stores the day's water for the evening, the night and cloudy days. Your tank size tells us whether the pump needs to fill it in one sunny day, or whether a smaller pump running all day is enough.

6. How thick is the pipe?

Thin pipe adds a lot of friction, especially over long distances and at higher flow rates. A pump that is right for 32mm pipe may struggle on 20mm pipe over the same distance. Tell us the pipe size (e.g. 25mm, 32mm or 40mm) so we can allow for it.

7. How much water do you need per day, or per hour?

As a rough guide, a household uses 150–250 litres per person per day. Livestock, gardens and irrigation need far more. A solar pump runs about 6 good sun hours a day, so divide your daily need by 6 to get the flow you need in litres per hour.

How we put it together

Total head = water level + tank height + friction (pipe distance and thickness).
Flow needed = daily water ÷ about 6 sun hours.

We then choose a pump whose maximum head is comfortably above your total head, and check its pump curve at your head to confirm the flow. A pump's flow drops sharply near its maximum head, so we always leave headroom.

Screw pump or centrifugal pump?

Screw-type (positive displacement): low power, good lift, steady low flow. Ideal for households and small livestock. Our range covers 56m (PUSC56), 77m (PUSC77) and 109m (PUSC10).

Centrifugal: higher flow for gardens, irrigation and larger herds. Options include 47m (PUBO47), 70m (PUBO70), 95m (PUBO95), 123m (PUBO123), 140m (PUBO140) and 203m (PUBO203) for very deep boreholes.

Solar or AC: some pumps run on solar during the day and on AC power when you need water at night or in bad weather.

Tips for a longer pump life

• Fit a float switch in the tank so the pump stops when the tank is full.
• A dry-run sensor protects the pump if the borehole level drops.
• Every pump comes with its own controller. Ask us for the right number of panels for your pump and head.

Prefer to let us do the maths? Try our pump selector: answer the same 7 questions and it suggests pumps from our range, then sends your answers to us on WhatsApp.

Send us your answers

Copy the checklist below, fill it in and send it to us on WhatsApp (082 515 1655) or email sales@thesunpays.co.za. Our own South African technical team will recommend the right pump.

1. Borehole depth: ___ m
2. Water level starts at: ___ m
3. Tank height above ground: ___ m
4. Distance from borehole to tank: ___ m
5. JoJo tank size: ___ L
6. Pipe size: ___ mm
7. Water needed: ___ L per day (or ___ L per hour)

Or browse our borehole pump range and the borehole pump technical guide. Most pump pages include the pump curve as a PDF.

← Previous Post Next Post →