A solar borehole pump runs on solar panels instead of the grid or a diesel engine. The panels drive the pump through a controller, so it pumps whenever the sun shines and fills a storage tank by day. There is no electricity bill, no fuel run and no worry about load-shedding. Solar pumps suit farms, game farms, smallholdings and homes with storage, and they are a common choice to replace an old windmill. This page explains how a kit works, how it is sized and what to ask before you buy.
How a solar pump kit works
A kit has a pump, a controller and a panel array. Many use a DC pump wired straight to the controller. Others use an ordinary AC pump run by a solar pump inverter, which can sometimes be switched to grid or generator power when needed. For deep holes with low flow, kits often use a helical rotor pump (positive displacement); for more water at lower head, a centrifugal pump. The controller usually adds dry run protection and a tank float input, so the pump stops when the hole runs low or the tank is full. Some controllers also show running hours and faults, which helps a technician on a farm visit.
Sizing the panels, pump and tank
Start with the water you need per day and the total head, then check the borehole yield. The supplier picks a pump that delivers that daily volume over the sunny hours, and sizes the panel array to the pump. The tank holds water for night and cloudy days, so many people size it for more than one day's use.
Flow drops in the morning, late afternoon and in cloud, so a solar pump gives less per hour than a grid pump of the same size. Send the yield test; never size beyond it. See borehole pumps for the basics.
Replacing a windmill
Many farms in the Karoo, the Free State and the Northern Cape swap windmills for solar pumps because a windmill stops when the wind drops and needs pump rod and leather work. A solar pump can often drop into the same hole, though the old rods and column must come out first and the casing must be checked. Keep the existing reservoir if it is sound. An installer will advise whether the hole is wide and straight enough. For crop water, see irrigation pumps.
Theft, mounting and what to compare
Panel and cable theft is a real risk in many areas. Ask about anti-theft bolts, welded or high frames, steel cages and burying the cable. Mount the panels facing north at a sensible tilt, clear of shade from trees.
Compare quotes on the daily volume at your head, the pump type, the panel count and wattage, the controller and its protection, the cable and pipe, the frame, and the warranty on each part.
What to put in your request
- Litres you need per day and what for
- Borehole depth, yield and pumping water level
- Height and distance to the storage tank
- Whether a windmill or old pump is being replaced
- Theft risk on the site and fencing in place
Solar Borehole Pumps for homes, farms and businesses
- Homeowners: a small solar pump filling a garden tank from the borehole without using grid power
- Smallholdings and plots: a solar kit keeping the house tank and animal troughs full through load-shedding
- Farms: replacing windmills and diesel pumps at remote boreholes for livestock and game
- Complexes, estates and body corporates: a solar pump filling irrigation tanks for the communal gardens
- Offices, shops, hotels and lodges: lodges and farm stalls pumping borehole water to storage far from the grid
- Factories, plants and depots: water for remote depots, yards and dust suppression without a grid connection
- Mines and quarries: solar pumps at remote boreholes supplying camps and exploration sites
- Municipalities, schools and clinics: village water schemes and rural standpipes fed from a solar borehole
- Contractors and drillers: installers fitting solar kits and frames, and removing old windmills
Frequently asked questions
Does a solar borehole pump work without batteries?
Will a solar pump work on cloudy days?
Can I keep my existing borehole pump and add panels?
Do you supply and install solar pump kits?
Solar Borehole Pumps by province and city
- Johannesburg
- Pretoria
- Centurion
- Midrand
- Sandton
- Randburg
- Roodepoort
- Krugersdorp
- Randfontein
- Germiston
- Boksburg
- Benoni
- Kempton Park
- Alberton
- Vanderbijlpark
- Vereeniging
- Durban
- Pinetown
- Pietermaritzburg
- Richards Bay
- Newcastle
- Ladysmith
- Gqeberha (Port Elizabeth)
- East London
- Kariega (Uitenhage)
- Mthatha
- Cape Town
- Bellville
- Paarl
- Stellenbosch
- George
- Worcester
- eMalahleni (Witbank)
- Middelburg
- Secunda
- Mbombela (Nelspruit)
- Rustenburg
- Brits
- Klerksdorp
- Potchefstroom
- Mahikeng
- Polokwane
- Tzaneen
- Kimberley
- Upington
- Bloemfontein
- Welkom
- Sasolburg