Borehole Pump Electricity Calculator (South Africa)
Work out what your borehole pump really costs to run in South Africa, per hour and per month, the off-peak saving on Eskom Ruraflex, and the cost to irrigate a hectare.
Most online borehole tools only price drilling and installation. This one works out what your pump actually costs to run, in rands per month and rands per thousand litres, on real South African tariffs. Eskom's Ruraflex tariff charges up to four times more for power at peak times than off-peak, so if you can shift your pumping to off-peak hours the saving is usually the biggest lever you have.
Not sure of the exact rating? Tap the nearest size above, most household and smallholder pumps fall in this range. Otherwise check the pump's data plate or invoice; bigger irrigation pumps can run well past 3 HP. 1 HP = 0.746 kW.
How deep the standing water sits below ground. Ask your driller, or check the borehole completion certificate.
Height the water must still rise above ground level to reach your tank or reservoir.
How much of the electricity actually becomes lifted water, wire to water. Textbooks quote 65 to 70%, but real farm submersible setups, with ageing pumps, bends and worn seals, more often land in the 35 to 50% range. Only push this higher if you have a recent, well matched pump.
Already includes a 10% allowance for pipe friction losses. This is a rough sizing estimate, not a substitute for your pump supplier's calculation.
Optional if you already know your pump's power. Needed to work out cost per 1 000 litres and the irrigation and reservoir figures below. Check the pump curve on your data plate, or a bucket-and-stopwatch test at the tap.
Average across a typical day, including any float switch or timer cycling.
7 for household or livestock water that runs every day; fewer if it is only for scheduled irrigation cycles.
Not sure which you're on? It's printed on your Eskom bill or notice of supply. Ruraflex charges a different rate at peak, standard and off-peak times; Landrate is one flat rate all day.
On your Eskom Ruraflex bill. If unsure, leave the default, it makes only a small difference.
The rest, 40%, falls in off-peak. Weekday peak is the morning and evening; off-peak is overnight and most of the weekend. Check the exact clock times on your Ruraflex tariff notice, they vary a little by supply area.
Default is the 2026/27 Landrate 1 all-in rate (energy, network and ancillary charges). Check your own bill for the exact figure, it varies slightly by connection size.
Use the energy charge per unit off your bill or prepaid receipt, not your whole bill divided by units.
Optional. 1 kL = 1 000 litres. We'll check whether it's big enough to store a full day's water, so you could shift all your pumping to off-peak hours without running dry during the day.
A typical irrigation cycle applies 15 to 30mm. Needs the flow rate on the pump tab.
Check your local price, it varies by region and moves monthly.
A mid-size diesel genset under a steady load typically uses 0.35 to 0.45 litres of diesel per kWh generated.
Leave at 0 unless you are a registered farming operation claiming the SARS diesel refund. The rebate rate changes, check your current registered rate on eFiling or with your accountant rather than guessing.
Most of South Africa averages around 5 peak sun hours a day; sunnier inland areas like the Northern Cape run higher, the KZN coast a little lower. A direct solar borehole pump normally only runs while the sun is up, no battery needed, so this assumes your pumping hours could move into the sunniest part of the day.
Cost to irrigate
Grid vs diesel generator
Solar saving potential
This is only the running cost avoided, it does not include what a solar pump conversion would cost to install. For a full realistic payback, including equipment cost, degradation and financing, try the Solar Savings & Payback Calculator.
These are estimates to help you budget and compare options, not a guarantee of your actual bill. Real running costs depend on your pump's condition, water table changes, pipe layout and the exact tariff clock times in your supply area. Always check the figures on your own Eskom bill.
💬 Discuss this tool, or check the off-peak saving against your own Eskom bill, on the forum →
How borehole running costs really work in South Africa
Most borehole calculators online only price the drilling and the pump itself, then stop. What they leave out is the ongoing electricity bill, which over a few years usually adds up to far more than the installation. That cost comes down to three things, how powerful your pump is, how many hours it runs, and critically, what tariff and time of day you are paying for. That last part is the one most farmers never see broken out, because a normal electricity bill just shows one total. As a rough anchor, a 1.1kW pump, roughly 1.5 horsepower, running four hours a day uses about 130 units, or kWh, a month, but what that costs in rands can easily double or triple depending purely on the tariff and time of day, which is the part this calculator actually shows you.
If you are on Eskom's Ruraflex tariff, the one most farms with a bigger connection sit on, the difference between peak and off-peak pricing is large. Peak rate electricity, the morning and evening on weekdays, can cost three to four times what the same unit costs off-peak overnight or over most of the weekend. A pump that runs whenever it happens to be needed, rather than on a schedule, quietly pays the expensive rate a lot of the time. Shifting that pumping into a storage tank overnight is usually the single biggest saving available, bigger than most equipment upgrades.
The calculator above works in both directions. If you know your pump's power rating off the data plate, put it straight in. If you do not, the estimate mode works out a rough kW figure from your borehole depth and desired flow, using a realistic wire to water efficiency rather than the optimistic number sometimes quoted. Either way, set your tariff, and it shows what you are actually paying now, in rands per month and rands per thousand litres, what you could save by moving to off-peak hours, and what the same water would cost applied to a field or drawn from a diesel generator instead.
While you are here, you can also check whether solar would pay off for your farm or home, work out how many units your prepaid electricity rands buy, or browse all our free South African tools and calculators.
Frequently asked questions
How much electricity does a borehole pump use in South Africa?
It depends entirely on the pump's power rating and how many hours a day it runs, there is no single answer. A typical household or smallholder submersible pump rated around 1 to 1.5kW, run for four hours a day, uses roughly 120 to 180 units a month. A bigger irrigation pump on a farm can easily use several times that. Check your pump's data plate for the kW rating, then multiply by the hours it actually runs to get your own figure, which is exactly what the calculator above does.
Why is my Eskom Ruraflex bill so much higher in winter?
Ruraflex charges a much steeper peak rate during the high demand season, June to August, when the whole grid is under the most strain. On the standard 2026/27 tariff the peak rate in winter can run close to four times the off-peak rate, while in the rest of the year the gap between peak and off-peak is smaller. If a chunk of your pumping happens to fall in the winter afternoon and evening peak, that alone can double or triple your electricity cost for the exact same amount of water.
How can I cut my borehole running costs without pumping less water?
The single biggest lever on a time-of-use tariff like Ruraflex is when you pump, not how much. Off-peak electricity typically costs a third to a quarter of the peak rate, so fitting a timer to run the pump overnight into a storage tank, then drawing from that tank during the day, can cut your bill sharply without changing your water use at all. It does mean you need enough tank capacity to cover a day's demand, which the calculator above checks for you.
Is Ruraflex or Landrate cheaper for a small borehole pump?
It depends on when you pump. Landrate is a single flat rate all day, simple and predictable. Ruraflex can be far cheaper if you can shift most of your pumping to off-peak hours, but it can also work out more expensive than Landrate if your pump mostly runs during the day, especially in the winter peak. If you cannot control when the pump runs, for example a float switch on a household supply that could kick in any time, a flat rate is often the safer, more predictable choice.
Is a diesel generator cheaper than grid power for a borehole pump?
Almost never for everyday running, only for backup during outages. Diesel generators typically cost somewhere between R6 and R12 a unit once you account for fuel burn, which is several times what you pay for grid electricity even on the expensive peak rate. Diesel makes sense as a backup for load shedding or grid faults, but running a borehole pump on diesel as the everyday power source is rarely worth it once you compare the real fuel cost, which is what the diesel comparison in the calculator above shows.
How do I work out my pump's power if I don't know the rating?
Use the estimate mode on the calculator, which needs your borehole's water depth, the extra height to your tank, and the flow rate you want. It works out the power from basic pump hydraulics, using a conservative real world efficiency rather than the optimistic figure often quoted on paper. It is a sizing estimate to sanity check a quote or an old pump, not a substitute for a proper pump selection by your supplier. If you only know it in horsepower, or roughly which size it is, the quick preset buttons on the calculator cover the common sizes from half a horsepower up to 3 horsepower.
How much could I save running my borehole pump on solar?
It depends on how many hours a day you pump versus how many hours of usable sun you get, since a direct solar borehole pump normally only runs while the sun is up unless you add a battery. If your daily pumping fits inside a typical sun day, solar could realistically cover the running cost entirely. If you pump for longer than that, only the sun hours portion is covered and the rest still needs grid or battery backup. The calculator's solar saving estimate only covers the running cost avoided, not what the conversion would cost to install, for that use the full Solar Savings & Payback Calculator linked above.
How much does it cost to run a borehole pump per hour in South Africa?
Multiply the pump's power rating in kW by your electricity rate in rands per kWh, that is your cost per hour of running time. As an example, a 1.1kW pump on a blended Ruraflex rate of around R2.90 a unit costs close to R3.20 an hour, more if that hour falls in the winter peak, notably less if it falls off-peak. The calculator above works this out from your actual pump size and tariff, and also converts it into cost per 1 000 litres, which is the number that actually lets you compare pumps of different sizes fairly.
How much does it cost to irrigate a hectare with a borehole pump?
It depends heavily on your pump, your tariff and how much water you apply, so there is no single national figure, but it is useful to have a benchmark. An SA Grain industry survey from 2022 put the typical spend at roughly R2 000 to R3 500 a hectare over a season, and electricity prices have only risen since. The calculator above works out the cost of a single irrigation cycle for your own pump, tariff and area, in both litres and rands, so you can multiply by how many cycles you run in a season and see where you sit against that range.
This calculator gives estimates to help you budget and compare options, it is general information and not a substitute for a proper pump selection or a quote from a qualified installer. Eskom Ruraflex and Landrate figures are the 2026/27 published rates for the most common zone and voltage, check your own bill for your exact rate. Last reviewed July 2026.