Solar borehole & submersible pump systems
A solar borehole system gets sized from the well, not from a motor rating. Give us the static water level, the drawdown and the daily demand. We work out what the submersible pump actually has to deliver, then build the solar side around that.
We supply the equipment package FOB China through audited partner factories. Drilling, pipework, foundations and installation stay with your local contractor.
Borehole and submersible: how the two words relate
Enquiries use the two words interchangeably. They describe different things, and the difference matters when you are comparing offers.
“Borehole” describes where the water is
A drilled well. It tells you the water is underground and that depth, water level and drawdown are going to drive the sizing.
“Submersible” describes how the pump is installed
The pump body sits under the water rather than above it. Submersible pumps are also used for drainage, sumps and sewage, which have nothing to do with a borehole.
In practice, a solar borehole system almost always uses a submersible pump, which is why the two terms travel together. This page covers that combination. If your water comes from a river, canal, tank or shallow sump, the pump usually sits above the water and the sizing works differently. Say so on the enquiry form and we handle it as a surface system.
What we need to know about your borehole
Six things. You do not need all six to start a conversation, but we cannot size anything without most of them.
Static water level
Where the water rests when the pump is off, measured from the wellhead.
Dynamic water level or drawdown
How much further the level falls once the pump runs. Most enquiries leave this out.
Borehole depth
Total drilled depth, and the depth you intend to set the pump at.
Daily water demand
Cubic metres per day, and whether it has to arrive within the solar window or around the clock.
Site location
Drives module temperature derating, wind loading on the structure, freight and which standards apply.
Existing power on site
Grid, generator or nothing, and whether it has to transfer automatically or just stand by.
Depth alone is not head. A 120 m borehole does not mean 120 m of head. It can be more, once you add drawdown, the lift to the tank, pipe friction and the pressure the irrigation line needs. It can also be a lot less, if the water rests much higher than the bottom of the hole.
How the system is put together
PV array
Modules on a ground-mounted structure sized for the local wind conditions. Strings are arranged so the array voltage stays inside the drive window across the site temperature range.
DC combiner and protection
String fusing where the string count requires it, surge protection, and a DC isolator so the array can be worked on safely.
Pump drive cabinet
Converts the array output to drive the motor, and holds the protection and control. Where the site has grid or a generator, this is also where transfer is arranged.
Submersible pump and motor cable
The pump itself, its motor cable down the borehole, and the protective earth.
We supply all four, plus the cabling and earthing materials. If you have already bought the pump, we quote items 01 to 03 against its nameplate instead. Say which on the enquiry form.
What the same motor power actually buys you
Enquiries often open with a power: “I need a 1.5 HP solar borehole pump.” Power on its own does not tell you how deep the pump will lift or how much it will move. These selected 3" and 4" catalogue examples share power ratings but have different hydraulic capabilities. Equal power does not establish identical motors, identical controllers or the output at your site.
| Power / type | Reference | Maximum flow (separate endpoint) | Maximum head (separate endpoint) |
|---|---|---|---|
| 750 W1 HP / DC; centrifugal / screw examples | CAT-0750-FCatalogue p. 13 | 10 m³/h | 50 m |
| 750 W1 HP / DC; centrifugal / screw examples | CAT-0750-HCatalogue p. 3 | 2 m³/h | 120 m |
| 1100 W1.5 HP / DC submersible examples | CAT-1100-FCatalogue p. 13 | 10 m³/h | 70 m |
| 1100 W1.5 HP / DC submersible examples | CAT-1100-HCatalogue p. 11 | 4.5 m³/h | 110 m |
| 1300 W1.75 HP / DC submersible examples | CAT-1300-FCatalogue p. 13 | 13 m³/h | 60 m |
| 1300 W1.75 HP / DC submersible examples | CAT-1300-HCatalogue p. 11 | 5.5 m³/h | 128 m |
| 1500 W2 HP / DC submersible examples | CAT-1500-FCatalogue p. 13 | 15 m³/h | 70 m |
| 1500 W2 HP / DC submersible examples | CAT-1500-HCatalogue p. 11 | 5 m³/h | 160 m |
| 2200 W3 HP / AC/DC hybrid submersible examples | CAT-2200-FCatalogue p. 26 | 22 m³/h | 62 m |
| 2200 W3 HP / AC/DC hybrid submersible examples | CAT-2200-HCatalogue p. 23 | 9 m³/h | 158 m |
Evidence register: OS-REF-PUMP-20260920. Transcriptions checked on . Reference IDs identify individual source records, not OmniSol product models. Request the model mapping and applicable documentation with your enquiry. Catalogue revision and test conditions are not confirmed; these are not independently tested results or a selection recommendation.
Read the two numbers correctly
A model listed as 15 m³/h and 70 m does not give you both at once. It reaches 70 m when the flow has fallen to nothing, and 15 m³/h when it is pushing against almost no head. Your site sits somewhere between, and only the curve tells you where.
Ask for a verified duty point
Maximum flow and maximum head do not define the intervening curve. Ask for the exact model curve, its document reference and revision, operating speed and your duty point marked on it. Do not infer output from a line between the endpoints. Longer version here.
Sizing: from well data to array size
The order matters. Establish the duty point first: the flow you need at the total dynamic head you actually have. Only then does a pump selection mean anything, and only after that can the array be sized.
Every selection we send comes with the flow-versus-head curve for that exact model and your duty point marked on it. Ask for the same from anyone else you are comparing. A catalogue maximum flow and a catalogue maximum head sit at opposite ends of one curve, and neither proves the point in between.
Tools and longer reads
Free, no account needed.
What is included, and what is not
In our scope
- •Submersible pump, motor and motor cable
- •PV modules, mounting structure, clamps and fixings
- •Pump drive / inverter cabinet with its protection devices
- •DC combiner, string cabling, connectors, earthing materials
- •String sizing checked against the drive window at your site temperatures
- •Export packing and shipping documents, FOB China
Not in our scope
- •Drilling, well development, casing or any well work
- •Riser pipe, valves, tanks and the irrigation network
- •Concrete foundations and civil works
- •Installation, commissioning labour and local connection
- •Abstraction permits and water rights
Reference design
Design work for a project under discussion. Design values, not readings from a running installation.
Five independent pumping systems on one farm near Riyadh, worked through in 3D: mounting arrangement, underground DC routing, earthing and the control cabinet.
Frequently asked questions
Is a borehole pump the same as a submersible pump?
They describe different things. Borehole describes where the water is, a drilled well. Submersible describes how the pump is installed, with the pump body under the water rather than above it. A solar borehole system almost always uses a submersible pump, which is why the terms travel together, but submersible pumps are also used for drainage, sumps and sewage.
Does a 120 m borehole mean I need 120 m of head?
No. Depth is not head. Water usually rests well above the bottom of the hole, so the real lift can be much less. It can also be more, once you add drawdown, the lift to the tank, pipe friction and the pressure the irrigation line needs. Measure from the wellhead down to the water, not to the bottom.
What size solar pump do I need for a 1.5 HP requirement?
Power on its own does not settle it. At 1100 W a current borehole range offers a pump reaching 10 m³/h with a maximum head of 70 m, and another reaching 4.5 m³/h with a maximum head of 110 m. Same motor, completely different jobs. The duty point, flow at your head, is what selects the pump.
What is drawdown and why do you keep asking for it?
Drawdown is how far the water level falls once the pump is running at the flow you want. It comes from the driller's pumping test. A pump sized against the resting level looks right in the morning and loses flow by midday, because the level it is actually lifting from is lower than the level you measured.
Do you supply the borehole pump as well as the solar side?
Yes. Pump, motor cable, drive cabinet, modules, mounting, DC cabling and protection ship as one package FOB China. If you have already bought the pump we quote the rest against its nameplate.
Can the system run at night or during cloudy weather?
A solar-only system pumps when the array can run it and stops when it cannot, which is why water is stored in a tank rather than energy in a battery. If the site has grid or a generator, the cabinet can be arranged to transfer automatically or to stand by for manual use. Say which you want; the three options price differently.
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Need project-specific engineering support?
Free CAD layout, wind/snow load calculations, and BOM review included with project orders.
Send us your borehole
Two boxes to start: a way to reply, and roughly where the site is. The water levels and depths can follow once you have them.