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FEATURE STORY August 26, 2021

Sri Lanka Can Gain a Myriad of Benefits from Twinning Floating Solar and Hydropower


Adding large-scale floating solar plants would not only make electricity greener and affordable but improve Sri Lanka’s competitiveness  Photo credit: The Solar Energy Research Institute of Singapore (SERIS)


  • Floating solar could bring multiple benefits such as better land utilisation, improved efficiency and it gives potential to help Sri Lanka meet its renewable energy goals
  • Globally over 30 countries have implemented 500 projects including Maldives and India
  • Comprehensive policy adaptation can help attract long term investors and tap climate finance options as Sri Lanka prepares to build back better post COVID-19 pandemic

Sri Lanka needs to add an estimated 11,000 MW to its power grid within the next two decades to meet growing demand. Adding large-scale floating solar plants would not only make electricity greener and affordable but improve Sri Lanka’s overall economic competitiveness as well.  

Sri Lanka’s energy policy is underpinned by the Government’s ambitious target of generating 70% of power from renewables by 2030. Solar power is one of the cheapest sources of energy and Sri Lanka has strong solar resources. However, ground-mounted solar power requires a lot of land and given Sri Lanka’s high population density, agriculture needs, and declining forest cover, land access can be challenging.

“Floating solar can potentially work well with hydro power generation. Any new power generation also requires new power infrastructure but if you put solar near hydro, the same power infrastructure can be used. Sri Lanka has many water bodies that could potentially be used for floating solar,” said World Bank Senior Water Supply and Sanitation Specialist Kristoffer Welsien.

By identifying large water bodies for floating solar, Sri Lanka also can tap into the multiple benefits of lower evaporation, higher solar panel efficiency due to cooling effect, complementarity with hydro power generation and, efficient management of peak hours. While environmental and social impacts need to be carefully studied and managed, strategic, and well-managed floating solar projects could also improve water quality by limiting algae growth.

The synergies from combining floating solar with existing hydropower plants can be significant and can add much-needed diversity to Sri Lanka’s power generation mix. Sri Lanka’s power mix could potentially benefit from greater solar power generation during the day and a switch to hydro in the night. Seasonally, floating solar could produce power during the dry months while throughout the monsoon rains hydro could play a larger role in the energy mix.      

One of the first floating photovoltaic or PV systems was built in 2007 in Aichi, Japan, followed by over 30 other countries on all continents. There are now over 500 projects and in total over 2 GW in operation world-wide. Over the years, the projects have moved from smaller demonstration projects to significant scales, with large capacity additions in development for example in India, Laos, Thailand, Vietnam, and China – the largest market for floating solar PV.

Winding tracts of solar panels are also popping up over water canals in neighbouring India where solar installations have been shifted to unusual locations to navigate high land prices.  A pilot project was touted in 2012, leading to the first large-scale canal-top solar power plant in the Vadodara district of Gujarat three years later. The Government rolled out the project as a Public Private Partnership (PPP).

Sri Lanka has also trialled a small pilot floating solar project, but its capacity is just some tens of kW. Experts believe that to reap economics of scale and for floating solar to make a significant contribution to power generation, projects need to be scaled up to about 100MW-200MW.

“We think this technology can make a significant contribution to meeting the renewable energy targets of Sri Lanka. Over time, it can help lower the overall cost of electricity supply in the country and complement existing power generation capacities, in particular hydro,” said the World Bank energy sector lead for Sri Lanka, Senior Energy Specialist Jari Väyrynen.   

For larger floating solar ventures, it is essential to focus on promoting well-structured and competitive procurement to drive down the costs. Adopting a strong policy framework from the onset is critical to manage risk, attract reliable and credible private sector partners as well as tap climate financing opportunities to help address barriers for implementation.

“Policy support would be useful on the implementation side for identifying and preparing sites, mobilizing financing, and enhancing technical capacity. The government can also further enhance administrative support from the Sustainable Energy Authority and other institutions for the permitting and licensing process.” Väyrynen noted.

Partnering with organisations that have the necessary capacity and expertise is also essential to work together towards a green, resilient and inclusive recovery. Multilateral organisations such as the World Bank can provide multi-dimensional support to countries keen to tap into innovative technologies emerging in the global renewable energy sector. The World Bank Energy Sector Management Assistance Program has done extensive global knowledge work on floating solar, including the Where Sun Meets Water publication series. In South Asia the World Bank is also supporting investments in floating solar in the Maldives and World Bank-Clean Technology Fund supported ‘Innovation in Solar Power & Hybrid technologies Project’ in India.

The synergies from combining floating solar with existing hydropower plants can be significant. Photo credit: The Solar Energy Research Institute of Singapore (SERIS)

Comprehensive and cohesive partnerships will also support the evolution of a local industry and services around renewable energy, including floating solar, to benefit from knowledge transfer and create job opportunities.  The typical lifecycle of a floating solar installation is about 25 years and the private sector can be tasked with proper decommissioning at the end of the project.   

“Optimized power procurement would include well-prepared and structured tenders. A multi-year program of pre-identified sites made available for developers and backed by a clear policy framework and feasibility studies would provide long-term term visibility and attract experienced project developers and financiers. Competitive tenders would also ensure achieving lowest possible cost of power from renewable energy projects in Sri Lanka” Väyrynen added.