How a Stellenbosch nursery helped GHJ Engineering Group prove the business case for agrivoltaics in South Africa
Published alongside GHJ Engineering Group’s case study on the Klapmuts Farm agrivoltaic greenhouse system
By Phumzile Sibisi
Chief Executive Officer
GHJ Engineering Group (Pty) Ltd
Klapmuts Farm, near Stellenbosch in the Western Cape, is a specialist horticultural nursery. Its business is producing ornamental plants, primarily French Hydrangeas, for garden centres and landscape contractors across the region. For years, though, the farm could not grow Hydrangea macrophylla at the volumes its customers wanted. The reasons were structural, not seasonal: intense direct summer sunlight scorched and bleached young seedlings, elevated temperatures suppressed the cool-night conditions this species needs to flower reliably, and the mains-powered climate control systems meant to compensate were both costly and, under load-shedding, unreliable.
This is the kind of problem GHJ Engineering Group exists to solve.
A model built around three harvests
GHJ Engineering Group was founded in March 2020 around a simple conviction: land in South Africa is usually asked to do only one job at a time, when it could be doing three. We call it our Triple Opportunity model, Harvest Energy, Harvest Crops, Harvest Returns. In practice, it means designing solar infrastructure that also creates the growing conditions a crop needs and structuring the investment so it produces a return a landowner can measure, not just a sustainability story they can tell. Klapmuts Farm became the proving ground for that model.
Building South Africa’s first purpose-built commercial agrivoltaic greenhouse
In partnership with Flomack and Greyton Electrical Solar, GHJ designed and installed what is understood to be South Africa’s first purpose-built commercial agrivoltaic greenhouse system, commissioned at Klapmuts Farm in 2024. A 73.2 kWp monocrystalline bifacial PV array of 120 panels is structurally integrated into the greenhouse’s gothic-arch steel frame, paired with a 60 kW hybrid inverter and a 120 kWh lithium iron phosphate battery bank. Total capital investment came to R2,293,197.
The panels sit at a 15-degree tilt, filtering approximately 35 to 55% of incoming solar radiation depending on the season — a light range that published horticultural research identifies as close to ideal for Hydrangea propagation. None of this would have come together without Peter Mackintosh at Flomack and Gideon Malherbe at Greyton Electrical Solar, our EPC partners on the build, or without the willingness of the team at Klapmuts Farm to test something no one else in the country had attempted commercially.
What the data shows
We recently published a detailed case study of the Klapmuts Farm system, evaluating real operational data across three areas: energy, agriculture, and tax. On energy, the results were larger than we expected. Peak monthly grid consumption fell by approximately 72%, from 16,380 kWh in January 2024 to 2,033 kWh in the same month a year later. Averaged across comparable months, the farm now draws approximately 2,211 kWh a month from the grid, down from approximately 9,433 kWh before installation, an annualised displacement of around 87,864 kWh, and estimated cost avoidance of R180,000 to R220,000 a year at current Eskom tariffs. The battery bank has also done something the utility bill alone doesn’t capture: it has removed the production disruptions that load-
shedding used to cause during irrigation and climate-control cycles. On agriculture, the greenhouse’s PV roof created close to the microclimate Hydrangea macrophylla needs — enough shade to prevent scorching, without starving the plants of light. The farm now runs a two-stage production cycle: seedlings are raised in the agrivoltaic greenhouse for eight to twelve weeks until root establishment, then moved to an adjacent shade-house to mature and flower. That has allowed Klapmuts to run multiple propagation cycles a year and meet supply commitments to retail customers that it could not fulfil before.
On tax, the case for South African investors is arguably the most underappreciated part of the story. Section 12B of the Income Tax Act allows a 100% first-year depreciation allowance on qualifying solar PV systems under 1 MW. At Klapmuts, that translated into a R618,163 tax benefit in the year the system was commissioned, cutting the effective net cost of the investment from R2,293,197 to R1,675,034 and meaningfully shortening the payback period.
≈72% Peak monthly grid draw reduction | R618,163 Section 12B tax benefit (Yr 1) | R180k–220k Estimated annual cost avoidance.
One farm, and a bigger point
As far as we can establish, Klapmuts Farm is one of the first commercial agrivoltaic greenhouse installations documented with real operating data anywhere in Sub-Saharan Africa. That is why we chose to publish the numbers, not just the story. South African horticulture is under pressure from Eskom tariffs that rose by an average of approximately 12% a year between 2022 and 2025, and from grid instability that disrupts irrigation and climate control at the worst possible moments. Agrivoltaics will not solve every part of that. Klapmuts shows it can solve more of it, on more fronts at once, than most farmers assume. It is also why GHJ’s pipeline leans deliberately toward women’s cooperatives, emerging farmers, and rural communities — the operators who stand to gain the most from land that works harder on their behalf.
Where this goes next?
We are not finished with Klapmuts. Future work will look at the system’s carbon impact, its potential to export power under the small-scale embedded generation programmes that Western Cape municipalities are beginning to roll out, and how multi-crop scheduling could push the model further.
A call to action
If you farm, invest in, or regulate land in Africa and are weighing whether agrivoltaics is worth the capital outlay, I would like to engage with you and explore opportunities within the agri-pV sector. That is what we built this case study to do, and it is why GHJ Engineering Group exists. GHJ is also thrilled to be part of C4SA’s AAPI, and excited to contribute to AgriPV taking off across Africa.