Winter is peak season for South Africa’s citrus industry. Cold storage facilities, packhouses and processing lines operate at full tilt - but so do electricity meters - as winter sees the harshest pricing under Eskom’s Ruralflex tariff, which heavily penalises usage during critical off-solar hours.
Ruralflex is a time-of-use (TOU), seasonally adjusted tariff. In winter, the most expensive electricity rates apply during peak hours: 6–8am and 5–8pm. These are precisely the periods when solar PV systems deliver little to no output. And those tariffs aren’t just high - they can exceed R7 per kilowatt-hour during these winter peaks - more than 3 times standard tariffs.
That is a real challenge for citrus farmers. Morning start-ups and evening pack-downs often require significant electricity - refrigeration systems ramp up, conveyors start rolling, and processing equipment comes online. Avoiding meeting that demand with expensive grid power means either relying on batteries or starting up a generator.
Battery systems can be designed to cover the morning and evening peaks, but the costs are substantial. Batteries must be large enough to carry multi-megawatt-hour loads through non-solar hours on a daily basis for several months - and then they sit underused for the rest of the year.
Batteries' capital inefficiency can make them a poor match for seasonal operations.
The citrus harvest and packout season typically spans five to six months, from late March into September, depending on region and cultivar. But it’s during June, July and August - the core winter months - that Eskom’s tariffs peak.
For many farms, those three months represent a disproportionate share of the annual electricity spend, especially during cold storage and high-throughput processing.
This is where LPG-fuelled gas engines show their value. A generator doesn’t care what time it is or how bright the sun is shining. It runs when needed and turns off when not - providing flexible, dispatchable power precisely during the highest tariff periods.
Importantly, many citrus farms in rural areas are also grappling with energy insecurity. Power interruptions, voltage instability, and unplanned load shedding are common - particularly in winter, when regional grid strain is most severe. Backup power becomes a necessity.
While diesel generators are often used, they are noisy, costly to run and maintain, have much shorter operating lives and come with a heavy emissions burden. LPG engines provide a cleaner, more efficient alternative that can double as both a cost-control mechanism during tariff peaks and a dependable standby power source when the grid falters.
Gas engines like those in the Guascor range are particularly well suited to this task. Not only do they deliver reliable on-demand power, but when configured as combined heat and power (CHP) units, they also recover waste heat for useful thermal loads - crate washing, sterilisation, or warm water needs. Alternatively the waste heat can be used in absorption chillers, for cold stores and refrigeration systems, further enhancing energy efficiency and reducing operational costs. That dual-output efficiency improves the return on every kilogram of fuel burned.
There’s also a clear emissions benefit. Eskom’s grid electricity emits over 900 kg of CO₂ per MWh, owing to its heavy coal base. An LPG-fuelled engine emits just 280–300 kg CO₂ per MWh — a two-thirds reduction in carbon intensity. In an industry increasingly exposed to export requirements around environmental standards, this matters.
Further complicating matters, Eskom has reached its capacity limits in many rural regions. Farmers seeking to expand operations are often told that no additional supply can be provided, or that major network upgrades must be paid for privately. This places a serious constraint on growth. With a self-generation solution like an LPG gas engine, farms can expand independently of Eskom’s limitations and timelines, avoiding the delays, costs, and uncertainty of grid-based infrastructure upgrades.
Solar PV still has a role - especially for year-round base loads that align well with daytime generation. These include borehole pumps, irrigation systems, farm offices, and staff housing. For these continuous loads, solar provides meaningful savings across all seasons.
But when your highest electricity costs are driven by non-solar time-of-use peaks in winter, solar alone simply can’t shield you. Batteries are technically feasible, but often don't make financial sense in highly seasonal operations.
An LPG generator, by contrast, offers simplicity and strategic value: switch it on when tariffs are high, switch it off when you don’t need it.
