Analysis · solar pumps
Solar borehole pump: does it pay for itself?
Solar is sold as the obvious partner for a borehole. We worked out how much electricity a borehole pump actually uses in each metro, and how long the extra cost of a solar pump takes to come back.
By Borehole Payback · updated 24 October 2026
Will a borehole pay for itself?
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Garden water from each metro's average 2021–2025 weather; 2026/27 water and sewage tariffs incl. VAT; pump electricity at R3.50 per kWh. Drilling at R1 000 per metre incl. casing.
What our numbers show
Our calculation: 60 m borehole, 250 m² garden, electricity at R3.50 per kWh; solar premium as published by installers in 2026
- Lifting a kilolitre from 60 m and pressurising it takes about 0.61 kWh. Watering a 250 m² garden, the pump uses R320 of electricity a year in Cape Town, R360 in Johannesburg, R391 in Pretoria and R169 in Durban.
- A solar pump set costs R35 000 to R75 000 more than a grid pump. Against those electricity bills it takes 97 years or more to pay back in Johannesburg, and longer everywhere else: longer than any pump or panel lasts.
- Even if the borehole also supplies the house, about 15 kl a month more, the pump's electricity only rises to R747 a year in Johannesburg.
- The reasons to buy solar are outside the bill: a borehole with no grid connection nearby, or water that must keep flowing during power cuts. For a suburban garden on the grid, the money is better spent on the borehole itself.
| eThekwini (Durban) | 207+ yrs | |
| Cape Town | 109+ yrs | |
| Johannesburg | 97+ yrs | |
| Tshwane (Pretoria) | 89+ yrs |
60 m borehole, 250 m² lawn watered fully from it, R3.50 per kWh. Not counting batteries, panel replacement or pump wear.
Electricity and payback by metro
| Metro | Pump electricity, garden only | Garden and house | Years for the solar premium to pay back (garden) |
|---|---|---|---|
| Cape Town | R320 / year | R707 / year | 109–234 yrs |
| Johannesburg | R360 / year | R747 / year | 97–208 yrs |
| Tshwane (Pretoria) | R391 / year | R778 / year | 89–192 yrs |
| eThekwini (Durban) | R169 / year | R555 / year | 207–445 yrs |
Pump energy: water lifted 60 m plus 30 m of pressure head, pump and motor 40 % efficient, R3.50 per kWh. Garden water from our day-by-day lawn model for 250 m²; "garden and house" adds 15 kl a month. Payback range uses the R35 000 and R75 000 premiums an installer published in September 2026.
Why the bill is so small
Water is heavy but a kilolitre does not need much energy to lift: raising 1 000 kg by 90 m is about 0.25 kWh of work, and a household pump turns electricity into lift at roughly 40 %. The expensive part of a borehole is the hole, not the power. That is also why our payback calculations barely change when we add pump electricity.
When solar does make sense
- No grid nearby. On a smallholding where bringing power to the borehole would cost more than the panels, solar is the cheaper connection.
- Power cuts. A grid pump stops when the power goes. If water must keep flowing, compare a solar set with a small inverter and battery for the existing pump.
- A big irrigation load. Farms and large properties pump far more than a garden; the sums change with the volume.
Questions owners ask
How much electricity does a borehole pump use?
About 0.61 kWh per kilolitre lifted from 60 m and pressurised. For a 250 m² garden that is R360 a year in Johannesburg at R3.50 per kWh.
Is a solar borehole pump worth it?
Not for the electricity it saves on a suburban garden borehole: the R35 000–R75 000 premium takes 97 years or more to come back. It makes sense off-grid or where water has to flow during power cuts.
This week
Metro of the week: eThekwini (Durban)
A household in eThekwini (Durban) using 30 kl of municipal water a month pays about R2 253 a month for water and sewage under the 2026/27 tariffs. A 60 m borehole watering a 250 m² garden would save about R4 769 a year after pump electricity and upkeep, and pay back in 19.8 years.