October 29, 2026 (Vanguard/All Africa Global Media via COMTEX) --
Lakes could soon serve a new purpose beyond fishing, tourism and other economic activities, as plans take shape to harness their surfaces for solar electricity generation.
The proposed projects would introduce a new approach to solar power generation, raising questions about how the installations would operate on water and what advantages they could offer over conventional land-based solar farms.
Theoneste Higaniro, Director of Generation and Transmission at the Energy Development Corporation Limited (EDCL), explained how the technology works and the considerations involved in installing solar panels on water bodies.
The government is seeking investors to develop a 200-megawatt floating solar power plant with battery storage on Lake Sake in Ngoma District, Eastern Province. Another installation is being considered for an artificial lake planned along the Nyabarongo River.
If implemented, the projects would become Rwanda's first floating solar power plants.
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How the floating solar plants would work
According to Higaniro, floating solar technology operates on the same principle as conventional solar power systems, with the main difference being where the panels are installed.
"The only difference is that floating solar panels are installed on water instead of land," he said.
The panels would be mounted on rafts or pontoons made from buoyant materials that keep the installations afloat.
Because the floating structures can move with wind and waves, they would be secured using anchors and mooring systems to keep them in position.
Anchors are placed on the lakebed, while mooring systems use ropes, cables or chains to connect the floating structures to fixed points, preventing them from drifting.
Like conventional solar installations, the panels capture sunlight and convert it into electricity, which is then processed through electrical equipment before being transmitted to the power grid.
Supervisory Control and Data Acquisition (SCADA) technology is also expected to be used to monitor and control operations.
SCADA is an industrial automation system that enables operators to monitor electricity generation, equipment performance and other operational conditions in real time.
Higaniro discussed the technology during the Global Off-Grid Solar Forum and Expo, which started on October 27 and ends on October 29.
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Saving land for other uses
Higaniro said one of the main advantages of floating solar technology is its potential to preserve land for agriculture and other productive activities.
Conventional solar farms require substantial land, which could otherwise be used for housing, agriculture, commercial developments or forestry.
"The main benefit is that we save cultivable land by installing solar panels on lakes. Solar panels require large areas of land, and opting for floating solar or combining floating and land-based installations offers greater flexibility while preserving land for other productive uses," he said.
"On lakes, we can also retain space for aquaculture and other activities without compromising agriculture and tourism on the shore," he added.
Beyond land conservation, Higaniro said solar energy offers environmental and economic advantages, although installation and operating costs vary depending on the technology and project requirements.
"Solar energy is renewable and inexhaustible. That is its main advantage, in addition to being clean. The cost of solar systems varies depending on several factors. The initial investment is lower than that of some other renewable energy systems, although operating costs may be relatively high. However, the technology is improving over time," he said.
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Could floating solar affect rainfall?
Higaniro also addressed concerns about whether floating solar installations could affect rainfall patterns by reducing evaporation from lakes.
Floating solar panels cover portions of the water surface, potentially reducing evaporation in the areas beneath them.
However, Higaniro explained that rainfall is influenced by several interconnected environmental factors rather than evaporation from individual lakes alone.
"Rainfall is not influenced by lakes alone. It is also influenced by the water cycle, including moisture recycling through forests and oceans," he said.
"We should not fail to harness our resources out of concern that floating solar will reduce evaporation. Floating solar does not eliminate evaporation completely, although it reduces it to some extent. This does not mean that rainfall in Rwanda will necessarily be affected by these projects, given the wider range of factors that influence rainfall," he added.
The potential environmental effects of floating solar installations, including their implications for aquatic ecosystems and water quality, are among the considerations that would need to be assessed during project planning.
Lessons from countries already using the technology
Dimitris Mentis, who leads the Energy Access Explorer platform at the World Resources Institute, said floating solar technology is already being used in several countries, offering lessons for Rwanda as it explores similar developments.
"Yes, it is feasible. Floating solar is already being used in other countries. For Rwanda, there is a need for initial pre-screening. This means identifying locations within a country where certain technologies, such as floating solar, could be deployed. You do not have to start from scratch," he said.
Such assessments can help identify suitable locations by examining the characteristics of water bodies, their potential for electricity generation and other technical and environmental considerations.
Several countries, including China, Japan, India, Indonesia, Thailand and Singapore, have developed floating solar plants on lakes, reservoirs and other water bodies.
China has installed floating solar facilities on lakes formed by subsidence at former coal-mining sites, including in Anhui Province.
Japan was among the early adopters of the technology, installing a commercial floating solar array on a golf course irrigation pond in 2007.
Indonesia inaugurated its Cirata floating solar power plant in November 2023. Developed by PLN Nusantara Power and the United Arab Emirates-based Masdar, the facility has a capacity of 145 megawatts of alternating-current output, equivalent to 192 megawatts of peak solar-panel capacity.
The project, which occupies approximately 200 hectares of reservoir surface, was designed to generate electricity equivalent to the needs of about 50,000 homes.
Thailand's 45MW floating solar plant at Sirindhorn Dam has been operating since 2021, while Singapore commissioned a 60MW floating solar installation on Tengeh Reservoir the same year.
India has also pursued floating solar projects on reservoirs and dams, including proposals involving the Tansa and Modak dams in Maharashtra.
Other countries, including Malaysia, Belgium and Portugal, have invested in or pursued floating solar developments.
In Africa, Zimbabwe has proposed a 600MW floating solar project on Lake Kariba, one of the world's largest artificial lakes.
South Korea has also planned a large floating solar development at Saemangeum, while China continues to expand its floating solar capacity through projects such as the Dezhou Dingzhuang installation.
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Growing interest in floating solar
Floating solar technology is attracting increasing attention as countries seek to expand renewable electricity generation while reducing competition for land.
For countries where land is limited or expensive, including Japan and Singapore, installing solar panels on existing water bodies provides an alternative to conventional ground-mounted solar farms.
The United Kingdom also adopted the technology, with Thames Water installing more than 23,000 solar photovoltaic panels on the Queen Elizabeth II Reservoir near London in 2016.
Although floating solar still represents a relatively small share of global solar capacity, interest in the technology has grown as countries explore additional ways of harnessing renewable energy.
According to a 2023 BBC report, floating solar installations accounted for less than one per cent of solar installations worldwide at the time.
The technology could offer opportunities for countries seeking to diversify electricity generation while balancing energy development with competing land-use demands.
For Rwanda, the proposed installations on Lake Sake and along the Nyabarongo River could mark a new phase in solar energy development, provided the projects secure investment and meet the necessary technical and environmental requirements.
COMTEX_1001959854/2029/2026-10-29T08:05:21
