Three Years Off-Grid on a Free State Farm: An Honest Review
People ask me about our solar system at least twice a week — usually farmers from neighbouring areas who are still running diesel generators around the clock and watching their fuel costs eat their margins alive. So I thought I'd write it all down properly once, with the actual numbers, the honest problems we had, and what I'd recommend to anyone thinking of making the switch.
We farm just outside Bethlehem. Our operation runs grain storage (maize and soya), a cattle feedlot with about 400 head capacity, a workshop, staff accommodation, and a farmhouse. Before solar, we were running a 60 kVA diesel generator as our primary power source — the grid out here is technically available but is unreliable enough that we hadn't trusted it for years. During load shedding, it didn't matter much because we were already off-grid with the generator. What the generator cost us, though, was a different story.
The Generator Costs Before Solar
I kept detailed fuel records. In 2022, the last full year before we switched, we consumed 84,600 litres of diesel for electricity generation alone (separate from tractor fuel). At an average price of R21.40/litre that year, that was R1,810,440 in electricity fuel. Add maintenance (R95,000), depreciation on two generators (R60,000), and the cost of a full-time person managing the generators and fuel logistics (R220,000 including employment costs). Total: R2,185,440 per year for electricity.
That figure made the solar quote feel a lot less frightening.
What We Installed
We went with a 120 kWp solar array — split between the barn roof (80 kWp) and ground-mounted frames on the south side of the workshop (40 kWp). Battery storage is 240 kWh of lithium, which gives us 2–2.5 days of critical load autonomy in full overcast conditions. We kept one of our diesel generators as a backup but it now runs only during extended bad weather — about 8–12 hours per month in winter, essentially nothing in summer.
Total system cost installed: R2,100,000. We financed 70% of it over 60 months. Net of financing costs and the fuel saving, we were cash flow positive from month two.
Year One: Teething Problems
I won't pretend year one was smooth. We had three issues worth mentioning.
First, one of the inverter units went into a fault state after a severe thunderstorm in December 2023. The installer came out and replaced a surge arrestor that had taken the hit — which is exactly what it's designed to do. We were down for about six hours while they sourced and fitted the replacement. In hindsight, keeping a spare surge arrestor on-site is sensible, and we do now.
Second, our grain auger — an old single-phase unit — didn't like the inverter's modified sine wave output. We replaced it with a direct-online three-phase motor and the problem was solved, but it cost us R18,000 we hadn't budgeted for. The lesson: if you have old single-phase inductive loads (some pump motors, older compressors), check their compatibility with the inverter output before installation, not after.
Third, the monitoring system wasn't configured to alert us when the battery fell below 40%. We came in one Monday morning after a cloudy weekend to find the generator had run all of Sunday night without anyone knowing. Not a disaster, but not what we wanted. The installer reconfigured the alerts remotely within the day.
Years Two and Three: Smooth and Profitable
After the year one learning curve, the system has been almost entirely problem-free. My fuel cost for electricity generation in 2024 was R112,000 — that's diesel for roughly 8–10 generator hours per month in winter. In 2022 it was R1,810,440. The saving is extraordinary.
I now pay my solar finance instalment of R29,000 per month and spend R9,000 per month on generator diesel and maintenance. Total electricity cost: R38,000 per month versus R182,000 per month before solar. The saving — R144,000 per month — is going straight into debt repayment and expansion capital. The solar system has been the single best investment this farm has made in 15 years.
The Unmeasured Benefits
Beyond the numbers, a few things I hadn't fully anticipated:
- No more fuel logistics: Coordinating diesel deliveries to a remote farm is a real operational headache. It's one fewer thing to manage.
- Staff conditions improved: Staff accommodation now has reliable power for cooking, refrigeration, and television 24/7. The difference in morale is noticeable.
- Equipment longevity: Our sensitive electronic equipment — the feedlot management system, the workshop welding machines' electronics — runs on cleaner power than the generator ever provided. We've had fewer electronic faults since switching.
- Fire risk reduction: We used to store 30,000 litres of diesel on-site. That's now down to 3,000 litres for the backup generator. The reduction in fire risk and the associated insurance impact was welcome.
Would I Do It Again?
Without hesitation, and I'd do it three years earlier. Anyone running a commercial agricultural operation in South Africa on a diesel generator is burning cash. The technology is mature, the installers are capable (choose carefully), and the financial case is overwhelming.
If you're a farmer or lodge operator reading this and still running diesel as your primary power source, call a solar company tomorrow. Not next month — tomorrow. Every month you wait is another month you're paying diesel prices for electricity.
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