Floating Solar Farms: Conserving Land and Water in South Africa
- Yolandi Botes
- Aug 11
- 15 min read
Floating solar farms, large arrays of solar panels deployed on water, are an emerging renewable energy solution offering a double benefit: clean power generation and conservation of precious land and water resources. In a water-scarce, land-conscious country like South Africa, these innovative installations hold significant promise.
This feature article explores what floating solar farms are, how they work, and why they are gaining traction in South Africa. It delves into their environmental advantages, real-world examples of projects, and the challenges that lie ahead, all in accessible terms for the general reader.
What Are Floating Solar Farms?
Floating solar farms (also known as floating photovoltaic or FPV systems) are solar power installations where panels are mounted on buoyant structures that float on bodies of water such as lakes, dams, reservoirs, or ponds. In essence, they function like conventional solar arrays but sit atop water instead of being fixed on land.
The panels are attached to pontoons or plastic floats, which are anchored or tethered to the shoreline or lakebed to keep the system stable and in place. Cables carry the electricity to inverters and transformers on shore (or on platform), feeding into the grid or local facilities just as a land-based system would.
Being on water does not diminish the panels’ ability to capture sunlight; in fact, it confers some benefits. The surrounding water naturally cools the solar panels, preventing overheating and thus helping them operate more efficiently than they might on hot dry land.
In sunny climates, high panel temperatures can reduce output, so the cooling effect of water can boost energy yield, some studies suggest by up to 10–15% in certain conditions. This means floating solar panels often generate as much or more electricity than similar panels on rooftops or the ground, while potentially lasting longer due to lower thermal stress.
Another advantage is that water surfaces are abundant and underutilized in many areas. Instead of consuming valuable real estate, a floating solar farm can tap into “liquid real estate”, the surfaces of dams, wastewater treatment ponds, irrigation reservoirs, and other artificial lakes.
Developers note this avoids competition with agricultural or ecologically sensitive land and can reduce community resistance that sometimes meets land-intensive solar projects. In short, floating solar lets countries with limited open land but sufficient water bodies generate significant power without sacrificing terrain needed for farming, housing or conservation.
How do they stay afloat? Most floating solar systems use modular high-density polyethylene (HDPE) floats that interlock to form a stable raft for the panels. These floating platforms are UV-resistant and designed to withstand long-term exposure to water without leaching contaminants. The entire raft is secured with an anchoring and mooring system tailored to the site’s conditions – for example, cables tied to weights on the reservoir floor or to the banks, allowing some flexibility for changing water levels and winds.
Electrical components are marinized for safety: wiring is insulated and often run through conduit above water, and any inverters on the platform are protected against splashes. Overall, the technology draws on proven practices from both the solar power industry and marine engineering, ensuring that “combining water with electricity” can be done safely.
Conserving Land with Water-Borne Solar
One of the strongest appeals of floating solar farms is their ability to save land space. Unlike traditional ground-mounted solar farms, which require large tracts of flat land, floating panels make use of surfaces that are typically not used for other purposes, namely, water bodies. In South Africa, where suitable land near consumption centers can be scarce or expensive, this is a major advantage.
The City of Cape Town, for instance, has highlighted that vacant land in urban areas is costly and limited, while rooftop installations alone cannot meet all energy needs. By installing solar on water reservoirs or treatment ponds, the city can add significant renewable generation capacity without eating into real estate that could be used for housing, agriculture, or industry.
“Given that vacant land in the city is very expensive and rooftop solar PV systems are relatively small, Cape Town aims to explore floating solar PV for larger-scale installations,” explained Councillor Phindile Maxiti, the city’s mayoral committee member for energy.
Floating solar preserves productive land in rural areas as well. Farmers who adopt FPV can continue using their fields for crops or grazing, since the solar arrays sit on farm dams rather than open ground.
A notable example is the Radley Landgoed farm in Mpumalanga province, which in 2024 commissioned one of South Africa’s largest floating solar systems. About 80% of the farm’s solar panels are installed on the surface of an irrigation dam, covering roughly 3,350 square meters of water. This design means the estate’s 1,900 hectares of arable land remain fully available for fruit orchards, sugarcane, and livestock, while the solar installation produces energy on otherwise unused water surface.
As the farm’s manager noted, choosing a water-based solar array avoided taking fields out of production – a crucial benefit for agriculture – and also had the side-effect of keeping the panels cooler and the dam water levels more stable. Aerial view of a floating solar farm covering an irrigation dam at Radley Landgoed, Mpumalanga. About 80% of the farm’s solar panels float on the water, saving farmland and taking advantage of the water’s cooling effect.
This 1.8 GWh-per-year array meets the electricity needs of the 1,900-hectare farm, allowing it to operate off-grid and buffer against load-shedding (rolling blackouts). Beyond farming, many ideal sites for floating solar in South Africa are man-made reservoirs tied to public utilities. A study by a local floating solar developer identified over 60 potential projects nationally, totaling more than 450 MW of capacity, at facilities like municipal wastewater treatment works.
These sites have a trifecta of reasons to go floating: they have significant on-site power demand, very little free land for ground panels, and open water ponds where evaporation is a concern. Installing solar on water in such cases not only generates electricity for the facility, but also helps the municipality preserve water and land resources. “Floating solar…has the dual benefit of producing power while reducing evaporation and preserving land for other use,” noted Peter Varndell, a spokesperson for Floating Solar (Pty) Ltd, which partnered on Cape Town’s pilot project.
Another land-related benefit is avoiding difficult terrain or ecologically sensitive areas. Solar farms on water do not require clearing vegetation or leveling ground, processes that can impact biodiversity. By using existing reservoirs (often human-made and already disturbed environments), floating installations can minimize additional environmental footprint on land.
They also bypass the issue of land ownership or community land rights that sometimes complicates renewable energy projects; water surface rights are usually under control of a utility or government, simplifying development. This is especially useful in South Africa, where land reform and competing land uses are socio-political factors. In summary, every megawatt of solar deployed on water is a megawatt not occupying terrestrial space, making floating solar an attractive route to expand renewables without encroaching on farmland, wild habitat, or costly real estate.
Preserving Water by Reducing Evaporation
In a country prone to droughts and water shortages, water conservation is as critical as energy generation. Floating solar farms directly address this by curbing evaporation from the water bodies they cover. The concept is intuitive: a layer of solar panels shades the water’s surface from the sun and acts as a physical barrier to wind, thereby slowing down the rate at which water evaporates into the air.
Less evaporation means more water retained in the reservoir for its primary uses (whether irrigation, drinking supply, or hydropower). This benefit is particularly valuable in South Africa’s arid regions and during recurring drought cycles. Research supports substantial water savings from FPV systems. For instance, a study on reservoirs in Africa found that covering just 1% of a hydropower dam’s surface with floating solar panels could reduce water losses enough to boost the dam’s annual electricity output by about 0.17% via improved water levels.
At higher coverage levels, the evaporation reduction is even more dramatic: modeling studies suggest that if nearly the entire surface were covered, evaporation could be cut by roughly half, though in practice only a fraction would typically be covered (tandfonline.com.) While covering large portions of a lake with solar modules is usually not feasible (nor desirable for ecosystem reasons), these findings highlight the significant dent in water loss that even moderate FPV installations can make.
Every bit of water saved is important in a water-scarce region, as one climate expert put it, countries will need to “cherish every last drop” as global heating intensifies droughts, so reducing reservoir evaporation is “significant”. South African pilots are already measuring this effect. The City of Cape Town’s first floating solar pilot, launched in 2021 at the Kraaifontein Wastewater Treatment Works, explicitly set out to quantify how much water a floating array can save.
In this research setup, two circular concrete reservoirs, each 20 meters in diameter, were used: one was covered by a ring of floating solar panels and the other left open as a control. By monitoring the water levels in both tanks over time, engineers can determine the evaporation difference attributable to the solar cover. The data collected over 12 months will inform the design of larger utility-scale floating solar projects in the future.
Early expectations are optimistic: city officials see floating solar as a way to secure a “double-win for sustainability”, generating clean power while reducing evaporation rates to save water. In a water-sensitive city that endured a severe drought just a few years ago, the prospect of solar panels helping to protect water supplies is highly appealing.
An aerial view of a small floating solar installation (upper reservoir) alongside an identical uncovered reservoir at Cape Town’s pilot site. Such floating systems can be deployed on water treatment ponds and farm dams, preserving land area and reducing evaporation. Data from this pilot will compare energy output and water savings between floating panels and traditional ground-mounted panels, guiding future projects.
Besides sheer water volume savings, water quality may also benefit. The shade provided by floating panels limits sunlight penetration into the water, which can suppress the growth of algae and other aquatic weeds. Excessive algal blooms, often a problem in warm, nutrient-rich South African dams, not only deplete oxygen and harm water ecosystems, but also complicate water treatment for human use.
By reducing algae growth, floating solar installations could improve the quality of stored water and reduce treatment costs for municipalities. (This positive side-effect has been observed elsewhere and is a subject of ongoing research in the local pilot projects.) In short, FPV helps keep more water in the reservoir and potentially keeps that water cleaner, a valuable combination for a country where every drop counts.
Floating Solar in South Africa: Projects and Progress
South Africa’s floating solar sector is still in its infancy, but a few pioneering projects have demonstrated the concept and paved the way for future expansion. The very first floating solar farm in the country was unveiled in early 2019 at the Marlenique Estate, a fruit farm and wedding venue near Franschhoek in the Western Cape. This installation, built by New Southern Energy, has a capacity of 60 kWp (kilowatt-peak) and floats on an irrigation dam at the farm.
It supplies a significant portion of the estate’s power needs, including running irrigation pumps for orchards, all while coexisting with the farm’s daily operations. Though modest in size, the Marlenique project was a proof of concept that floating solar can work in the South African context. It also showcased the use of specialised Hydrelio® floats (a French technology) to keep the panels above water, a system now common in many floating projects worldwide for its durability and 20+ year lifespan.
Since 2019, a handful of other floating solar endeavors have emerged, primarily led by private sector and research initiatives:
Radley Landgoed Floating Solar Plant (Mpumalanga)- Completed in 2024, this is one of the largest FPV installations in Southern Africa to date, situated on a farm dam. It consists of 3,350 m² of solar panels on water, totaling an energy output of up to 1.8 GWh per year. The system powers the entire 1,900-ha family farm (homesteads, packhouses, staff quarters) and is connected by a 7 km private grid on the property.
Thanks to this floating array, the farm has greatly reduced its reliance on the national utility Eskom, insulating operations from load-shedding outages. Project developers highlighted that the floating design “offers several benefits: preserving productive land, maintaining optimal irrigation levels, and providing cooling for the panels”. Financed by a major bank and using local engineering, the Radley project demonstrates the commercial viability of medium-scale floating solar for agricultural energy security.
City of Cape Town Floating Solar Pilot (Western Cape) – Launched in October 2021 at a wastewater treatment works, this pilot consists of a small floating array (only 9 solar panels, ~3.5 kW) on a reservoir, paired with a similar-sized ground array for comparison. Though tiny, its purpose is strategic: to gather empirical data on energy performance and evaporation reduction in South African conditions.
Over 12 months, the city and its research partners (including the Water Research Commission and University of Cape Town) monitored how the floating panels performed relative to the ground-mounted ones, and how much water was saved in the covered reservoir vs. the uncovered one. This information will inform larger planned projects, as Cape Town aims to roll out utility-scale floating solar at suitable sites through competitive bids in coming years. The city’s rationale is clear: with a target of 300 MW of renewables by 2030 (50 MW of which city-owned), and limited land available, reservoirs and ponds present an untapped resource for solar generation.
Marlenique Estate (Western Cape) – Mentioned above as the first installation, its success has been modest but symbolic. The 60 kW system continues to operate, offsetting a portion of the farm’s electricity usage with clean power. It proved that even smaller businesses and farms can adopt floating solar to cut energy costs and carbon footprint. The project also garnered attention for using environmentally friendly materials (the floats are recyclable plastic and don’t pollute the water). It earned accolades in sustainability circles and spurred interest from other agribusinesses in the region.
Other Notable Mentions: While full-scale floating solar hasn’t yet been built on South Africa’s big public dams, feasibility studies are underway. Researchers have evaluated sites like the Inanda Dam in KwaZulu-Natal for potential large FPV installations. Inanda, which supplies water to Durban, could host a sizable floating array that would augment power for the municipality while reducing evaporation.
There are also indications that state-owned power utility Eskom and the Department of Water and Sanitation are exploring floating solar options on some reservoirs, given the success of projects elsewhere in Africa (for example, Ghana’s 5 MW floating solar plant at the Bui hydropower dam). As of 2025, South Africa’s cumulative installed floating solar capacity remains small, on the order of just a few megawatts, but the pipeline is growing as awareness increases. Developers have identified nearly a thousand potential FPV sites at water treatment works alone, and private-public partnerships are likely to drive more projects in the near future.
Challenges and Limitations in Deployment
Despite the clear benefits, floating solar farms are not without challenges, especially in the South African context. As a relatively new technology, FPV faces technical, financial, and regulatory hurdles that need to be managed for wider adoption:
Higher Upfront Costs: Floating solar installations tend to cost more per watt than equivalent ground-mounted systems. The need for floats, anchors, and marine-grade electrical components adds to capital expenditure. Estimates from international case studies and experts in South Africa suggest FPV can be around 20–25% more expensive than traditional land solar in initial costs.
“The technology is excellent, but rather expensive,” notes Dr. Mmantsae Moche Diale, a solar researcher at the University of Pretoria, pointing out that the price premium remains a barrier. However, some of this cost difference can be offset by savings on land acquisition and by the higher energy yield of cooler panels. As the industry matures and local suppliers enter the market, costs are expected to come down.
Engineering for Harsh Conditions: South Africa’s large reservoirs (like big dams used for water supply or hydropower) present tougher conditions than the calm ponds where many early floating plants were built. Strong winds and waves on open dams can stress the floating structures, potentially causing wear and tear or even damage if not properly engineered.
Designers must use robust anchoring systems to handle fluctuating water levels and gusty winds; for instance, cables need to maintain tension through seasons of drought and heavy rain. If a floating solar island were to break loose in a dam, it could pose a hazard by drifting into dam spillways or intakes. To prevent such scenarios, extra safety measures (like perimeter booms or fail-safe anchors) are required for FPV on critical water infrastructure.
All this adds complexity to design, construction, and maintenance. In short, engineering FPV for large dams demands careful risk management, advanced simulations of wind/wave forces, and often a phased approach (starting with small sections to monitor performance). South African engineers are still building experience in this field, often in collaboration with international FPV specialists.
Regulatory and Permitting Hurdles: Being new, floating solar doesn’t have a fully defined permitting pathway in South Africa yet. Environmental impact assessments must consider aquatic ecosystems, for example, ensuring the panels don’t unduly harm water quality or fish habitat, and this area requires more local study. There may also be questions about water-use rights and whether covering a portion of a public dam with solar infrastructure needs special permission or community consultation.
Government support will be crucial: clear guidelines, incentive programs, or inclusion of FPV in renewable energy procurement rounds could accelerate adoption. As of now, projects are assessed on a case-by-case basis. The potential is attracting attention, but policy frameworks are only beginning to catch up.
Grid Connectivity and Location Constraints: Many of the reservoirs suitable for floating solar (like remote farm dams or rural water supply lakes) are far from existing grid infrastructure or load centers. Tapping their full potential might require new power lines or integration with local mini-grids. If the national grid is unreliable (as seen with load-shedding), having FPV is beneficial for local use, but exporting excess power can be a challenge without robust connections.
This means some floating projects might be limited to off-grid or self-consumption models unless grid capacity in the area is upgraded. In South Africa’s case, a lot of ideal FPV sites (such as water treatment plants) fortunately already have electricity demand on-site, but feeding surplus solar power into the wider grid will require technical and regulatory solutions (such as wheeling agreements or battery storage to manage output).
Maintenance and Skills: Operating solar panels on water demands a slightly different skill set and maintenance regime. For example, technicians may need boats or floating walkways to access the panels for cleaning and repairs. While FPV arrays typically stay cleaner (less dust than ground panels) and avoid issues like weeds or theft, there can be concerns like biofouling (build-up of organisms on floats) or the wear on mechanical parts due to constant motion.
Developing local expertise in maintaining floating solar farms is necessary. South Africa’s renewable energy industry and academic institutions have begun training efforts, but as FPV scales up, more technicians will need to be familiar with water-based systems.
Social and Environmental Considerations: As with any infrastructure on shared resources, engaging local communities early is vital. Communities that rely on a lake for fishing, recreation or cultural reasons might be wary of seeing part of it covered with solar panels. Transparent consultation and ensuring that the project doesn’t impede other uses of the water help in gaining public acceptance.
On the environmental side, more research is needed locally to confirm that floating solar platforms do not adversely affect reservoir stratification (the natural layering of water), aquatic life under the arrays, or bird activity. The preliminary evidence globally is reassuring, impacts seem minimal if the array covers only a modest fraction of the water and is properly sited, but local environmental impact assessments are now a standard part of FPV project planning.
South African authorities are cautious but supportive: the idea is to proceed with pilots and small projects first, demonstrating success and learning any ecological effects, before moving to very large installations.
Despite these challenges, the outlook for floating solar in South Africa remains positive. Experience from abroad shows that once the first few projects prove their worth, the technology can scale up rapidly. For instance, countries like China, India, and Japan have deployed huge floating solar farms (in the tens or hundreds of megawatts), driving costs down and refining best practices. Africa is catching up, Ghana, Kenya, and Seychelles have all installed or are building notable FPV, and South Africa is well-positioned to leverage its strong solar industry expertise.
As one energy analyst quipped, when you think about integrating solar with existing hydropower dams, “it’s just solar on a boat”, a simple idea that makes perfect sense. The dams already have the grid connection and available surface, so adding solar boosts power supply with little downside. Indeed, “sticking solar on hydro plants should be an obvious win”, says Jenny Chase, a renewables specialist at BloombergNEF. The same principle can apply to any calm body of water with good sun exposure.
Floating solar farms offer South Africa a compelling way to expand renewable energy generation while simultaneously addressing land scarcity and water conservation, two pressing issues for the country. By turning dams and reservoirs into dual-purpose energy and water assets, FPV technology exemplifies a smart, efficient use of resources. Early projects in the Western Cape and Mpumalanga have demonstrated tangible benefits: farms and municipalities are generating electricity without sacrificing land, and initial data show meaningful water savings from reduced evaporation.
These successes, though on a small scale, point to a future where many of South Africa’s irrigation dams, water treatment ponds, and perhaps even large hydropower reservoirs could be sporting glittering carpets of solar panels. There are hurdles to overcome, from higher upfront costs and engineering challenges to the need for supportive policies and careful environmental management. Floating solar will not replace ground-mounted solar or wind farms, but it will add another tool in the renewable energy toolbox, one particularly suited to a country with abundant sunshine and precious water resources.
As climate change exerts more pressure on water supplies and energy systems, innovative hybrids like floating solar can provide resilient solutions. In South Africa’s pursuit of sustainable development, floating solar farms may soon move from novelty to mainstream, helping to power the nation while conserving the land and water that are the lifeblood of its people.
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