By Alok Kumar, Regional Renewables Sales Manager, Asia Pacific, Energy Systems, DNV Advisory
The recent COP28 in Dubai witnessed 118 countries committing to tripling installed renewable capacity to at least 11,000 GW by 2030. India was not one of them, but its energy transition ambitions share an identical set of challenges compounded by local considerations. As we accelerate towards a sustainable energy future, there will be increased pressure on land and water resources. Renewable sources, such as ground-mounted solar, require more land, and the production of green hydrogen through electrolysis further strains already scarce water sources. In addition, the transition necessitates a significant investment in electrical infrastructure, with renewables requiring three to four times more infrastructure than conventional power sources. Despatchability or firm power becomes a focal point as more renewable energy integrates into the grid.
Floating solar offers a versatile solution to the challenges posed by the evolving energy landscape. Installing solar photovoltaic on water surfaces avoids competition for land and contributes to water conservation by reducing annual evaporation by more than 6 per cent. When integrated with hydropower plants operating at less than full capacity, floating solar seamlessly integrates into the existing electrical infrastructure. It also functions as a virtual battery, enabling the accumulation or conservation of water during periods of high solar power generation. The water can then be utilised during periods of low irradiation.
While the sector is in its infancy and implementation is progressing slowly, it could still play a valuable role in the global and Asian efforts to prevent the most damaging effects of global warming. DNV’s Energy Transition Outlook for 2023 delivers a stark warning that the “most likely” outcome of current trends is a breach of the Paris Agreement to limit global warming to 1.5 °C above pre-industrial levels. The outlook predicts global warming of 2.2 °C by 2100, with potentially catastrophic ramifications worldwide, especially in Asia. The adverse impacts of climate change are already evident, and their frequency and intensity are poised to escalate.
Other advantages
In addition to the above-mentioned benefits, floating solar offers distinct advantages over other renewable energy sources. Solar efficiency typically diminishes with increased temperature. Floating solar on water surfaces consistently maintains lower temperatures than ground-mounted solar set-ups, resulting in enhanced efficiency.
Furthermore, floating solar harnesses the inherent reflective properties of waterbodies, enhancing the albedo effect and thereby amplifying the efficiency of solar panels. The shading effect of floating solar serves as a natural deterrent to harmful algal growth, playing a crucial role in preserving ecological balance and maintaining water quality.
Floating solar can also contribute to enhanced production of high-protein food. Solar-powered aerators in remote fish ponds, situated far from the main electricity grid, have proven to be efficient in enhancing dissolved oxygen levels in water, promoting the growth and survival of aquatic life.
Potential
According to a report published by TERI in 2020, India has 280 GW of floating solar potential, which comes from covering 3-30 per cent of the surface area of man-made reservoirs. Maharashtra has the highest potential at 57 GW, followed by Karnataka (33.4 GW) and Madhya Pradesh (31 GW).
Precipitation variability due to climate change and the ageing of large-scale dams impact the performance and reliability of hydropower plants, causing power output and revenues to fall below the targets set by the Central Electricity Authority. This power output shortfall opens up capacity in the grid to integrate over 10 GW of floating solar power. The strategic deployment of floating solar at such hydropower plants optimises the utilisation of existing electrical infrastructure and creates additional revenue streams.
Similarly, there is untapped potential exceeding 3 GW for deploying floating solar on thermal power plants and irrigation dams. Water conservation is paramount for thermal power plants, especially in water-scarce regions where many such plants are situated. The power generated from floating solar can be utilised for the auxiliary consumption of thermal power plants, further enhancing their sustainability.
Over 5 GW of potential can be explored for the deployment of floating solar on lakes. The generated revenue can serve dual purposes – contributing to the maintenance of the lakes and providing minigrid solutions to remote areas. This multifaceted potential underscores the transformative impact that harnessing floating solar can have on India’s energy landscape, offering not just clean energy but also innovative solutions for sustainable water use and rural electrification.
Challenges
Last year, the spotlight was on the groundbreaking 100 MW floating solar project in Ramagundam, Telangana, marking India’s largest fully commissioned and operational floating solar project. This floating solar plant was integrated to an existing grid connected to a 2,640 MW thermal power plant. According to a July 2022 press release from the Ministry of Power, this project is set to prevent nearly 3.25 million cubic metres of water from evaporation annually.
Despite the success of this remarkable project, the total installed capacity of floating solar in India remains modest at less than 500 MW. Floating solar, priced 25-30 per cent higher than its ground-mounted counterpart, is at a nascent stage and is facing numerous challenges that impede its scalability.
Currently, India lacks policies and incentives dedicated to floating solar, creating a void that impacts private sector players, especially those navigating emerging industries. The fragmented approach to project development, coupled with supply chain bottlenecks and industry inexperience, impede the creation of an attractive investment landscape. The high investment costs associated with adapting to complex waterbodies further exacerbate these challenges.
Entering this arena proves risky for major players grappling with issues related to pricing, policies and volume visibility. There is also an absence of reliable historical data and a shortage of expertise in the design of floaters, anchoring and mooring systems.
However, the most pressing challenge emerges from the absence of specific standards, impacting the entire floating solar value chain – from initial feasibility studies to design, testing, construction and operation. There is also a need for customised testing infrastructure for structures while recognising the diversity in float designs and site conditions to optimise and validate product designs.
Recommended practices
In early 2021, DNV published the world’s first recommended practice (RP) for floating solar power projects following a collaborative joint industry project (JIP) involving 24 industry leaders from relevant fields. An Indian company, Quant Solar, participated in the JIP to represent the issues and challenges specific to this region. The objective of the resultant RP, DNV-RP-0584, is to provide a comprehensive set of requirements, recommendations and guidelines for the design, development, operation and decommissioning of floating solar systems. It aims to be valid and applicable in all major markets and geographic regions, for all defined applications within scope, from the component level to the system level, covering the entire life cycle.
End users, developers, suppliers, investors, authorities and other stakeholders can use DNV-RP-0584 as a single all-encompassing guidance document for such systems, providing direct guidance or reference to other existing relevant guidelines and standards. This RP aims to address some of the aforementioned major challenges related to the standardisation of floating solar worldwide.
The way forward
Given India’s substantial electricity demand and high population density, the country faces increased pressure on both land and water resources. Consequently, the strategic development and expansion of the floating solar sector become imperative.
It is crucial for the Government of India to prioritise and systematically nurture this sector. Drawing inspiration from the FOWIND study – an EU-funded initiative that meticulously explored the offshore wind potential and roadmap studies for India – a comparable study is needed for floating solar. This study should encompass the identification of potential sites, resource characterisation, site prioritisation, and the formulation of a systematic roadmap. Establishing short-term and mid-term targets would further enhance the precision of goals for floating solar development.
Prioritising less complex waterbodies and creating a comprehensive databank, housing both technical and non-technical information, will expedite the identification of easily attainable objectives and accelerate early developmental studies. Implementing a plug-and-play model akin to solar parks for large-scale projects will offer the much-needed scalability, fostering long-term investment, capacity building, and a thriving ecosystem for research and development.
On the regulatory front, establishing a single-window facility for approvals, accompanied by clear guidelines and diverse business models tailored for different waterbodies, is essential for ensuring stable and steady sectoral development. Given India’s vast size and geographical diversity, the country has the potential to assume a prominent role in the entire value chain of floating solar in Asia. Mainstreaming and scaling up this critical sector will be pivotal to achieving this broader regional impact.
