A solar bore pump runs directly off solar panels, so it can lift water at a remote site with no mains power and no generator. It pumps while the sun is up and slows or stops when it isn't. That changes how you size one: instead of asking for a certain flow on demand, you work out how much water you need each day and store it.
The solar pump range PSA stocks is the Pedrollo Fluid Solar, a 4 inch stainless steel submersible pump made in Italy for bores, wells and reservoirs.
The four models
| Model | Motor | Max flow | Max head | Price |
|---|---|---|---|---|
| Fluid Solar 4/4 | 750W | 100 L/min | 38m | $5,484.55 |
| Fluid Solar 2/6 | 750W | 75 L/min | 64m | $5,484.55 |
| Fluid Solar 4/8 | 750W | 120 L/min | 85m | $6,909.05 |
| Fluid Solar 2/14 | 1500W | 70 L/min | 140m | $6,909.05 |
The pattern is the usual one for multistage pumps: the "2" models are built for height and the "4" models for volume. The 2/14 reaches the deepest bores but moves the least water; the 4/8 moves the most water and still reaches 85m.
Max flow and max head don't happen together
Like any pump, the maximum flow is at low head and the maximum head is at almost no flow. A 4/4 lifting water 35m won't deliver anywhere near 100 L/min. Read the pump curve in the datasheet (under Downloads on each product page) at your actual total head, not the headline figures.
Working out total head
Add up:
- Pumping water level: the depth of the water in the bore while it's being pumped, which is usually lower than the resting level. A bore test or driller's report gives this.
- Height to the outlet: from ground level to the top of the tank or the highest delivery point.
- Friction loss: in the rising main and the delivery pipe, which grows with pipe length and flow and shrinks with a bigger pipe.
Choose a pump whose curve gives the flow you need at that total, with some margin.
Size around the daily volume
Because output depends on sunlight, the useful question is how many litres a day the pump delivers at your head, across the hours of good sun at your site. Work out the daily need (stock, house, garden), then make sure the pump's output at your head over your usable sun hours covers it, ideally with room to spare in winter.
A storage tank does the rest. The pump fills it during the day, and gravity or a pressure pump supplies from it at night and on cloudy days. Most off-grid systems are designed around several days of storage.
Panels and mounting
Pedrollo lists a 275W polycrystalline 60-cell panel pack (4 or 8 panels) and a PV-EZRACK post mount kit for these pumps, but neither is orderable online at the moment. Contact PSA if you need the matching panels and mount, and check the datasheet for the panel array the pump needs. Electrical installation should be done by a licensed electrician.
Other checks
- Bore size. These are 4 inch pumps, so the bore casing has to suit a 4 inch pump with clearance.
- Water quality. Sand and silt wear any bore pump. Ask your driller about the bore's sand content.
- Running dry. Make sure the pump sits well below the pumping water level, and ask PSA about dry-run protection for your setup.
If the site has mains power, see our guide to sizing a 4 inch mains-powered bore pump. The Fluid Solar range is available to order on backorder; contact PSA to confirm lead time.
Frequently Asked Questions
Which Pedrollo Fluid Solar pump reaches the deepest bore?
The Fluid Solar 2/14, listed at up to 140m head and 70 L/min maximum flow, with a 1500W motor.
Does a solar bore pump work at night?
No. It pumps while the sun is up, so off-grid systems pump into a storage tank during the day and supply from the tank at night and on cloudy days.
How do I size a solar bore pump?
Work out total head (pumping water level, lift to the outlet and friction), then pick a pump whose output at that head over your usable sun hours covers your daily water need.
Are the solar panels included?
No. The panel pack and post mount kit are listed separately and aren't orderable online at the moment. Contact PSA for panels to suit the pump.