India has seen massive growth in solar PV installations since it launched Jawaharlal Nehru National Solar Mission in 2010 and revised its target in 2015. Since its inception, the mission has succeeded in creating the domestic market for Multi-MW PV power plant developers through an e-reverse auction mechanism. In the last nine years, developers have scaled up their installation capability from several MW to several hundreds of MW. According to IRENA report, the cost of installing utility-scale solar PV projects in India has declined by a record 84% between 2010 and 2018. Government policies have delivered positive outcomes in terms of market development (like for the new technology of floatovoltaics) as well as the number of installations. However, there has been a rise in the project execution delays in the recent past due to the number of reasons like challenges in land acquisition, delays in building transmission evacuation infrastructure, legal concerns with government duties imposed on imported PV cells and modules, etc.
Background and Introduction
To cope with the issues and to explore the new technological avenues to expedite the installation of PV plants, various urban development bodies and government implementing agencies have started issuing tenders related to floating solar PV (FSPV) plants. FSPV’s are the PV arrays installed on a special structure that floats on natural or artificially created water bodies (like a lake, backwater of a dam, etc). The first floating solar PV plant with 10kW capacity was installed in Rajarhat, Kolkata in 2014. Since then, the FSPV vertical in the solar industry is advancing at a steady pace despite technology’s steep learning curve. India has installed capacity of 2.7 GW of FSPV as of 2018. Projects worth cumulative capacity of around 1.7 GW are under development at the moment. The numbers show that FSPV technology can play a vital role in strengthening the country’s green energy aspirations.
In a recent study performed by TERI, a list of water bodies across the country along with their FSPV potential under different scenarios is studied. It should be noted that different water bodies are used for different purposes like irrigation, navigation, hydroelectric, etc. Only some percentage of the actual geographical area of any water reservoir can be used for floating solar PV systems due to various complexities like change in water level, preservation of underwater aquatic life, etc. Based on the percentage of usable water area out of all reservoir areas, the study concludes that India has the potential of 78 GW of floating solar with a percentage of useable water ranging between 1% to 5%. If the percentage of useable water area changed to 2 to 30% then the available potential increases to 280 GW, i.e. around 3.5 times more than the earlier scenario. This makes it necessary to perform a detailed techno-sociology-ecological study of enlisted sites to discover the actual potential of the market. TERI report has estimated State-wise estimated potential of FSPV of India under different scenarios as shown in the following chart;
Challenge and Opportunities
Estimation of the depth of the water body is a critical stage in system designing as a well-designed anchoring and mooring system plays a crucial role in safeguarding floating structure during unforeseen events. In light of this, separate bathymetry and hydrography surveys are required to be conducted to preserve local ecology and ensure the safety of installed floating plants over the long period. State and local governments are required to actively engage in such exercise as the output of the same will enable them in formulating sustainable policy guidelines.
Every new technology comes with its pros and cons and floatovoltaics (the terminology used for floating solar PV technology) is not an exception! A marginal requirement of land (for transmission evacuation system and inverters in some cases) has been the unique selling point of FSPV but its performance reliability and long term ecological impact are yet to be assessed in detail.
Engineering solutions for floating platform/structure, sturdy anchoring, and mooring system are at the center of research as these are the most crucial parts of any floatovoltaic project. As of now, HDPE, MDPE, and FRP materials are being used for the pure floating system. Metal structures supported by pontoons are also being used. Developing innovative floating structures and their large volume deployment is supposed to bring down the overall cost of the project as they consume the second-highest share in the capital investment cost-breakup. This will improve project financing and encourage many players to enter the market. Even with the reduced cost, investment risks in floating PV systems will be higher as they have not yet proven their long term reliability in the real world. Till that time, dedicated government financial support for floating PV projects becomes necessary to expedite its deployment.
Apart from above, issues like best installation guidelines, clarifications on insurance policies, ownership of plants and water bodies, challenges in operation, maintenance and monitoring, etc. need to be discussed extensively by bringing traditional as well as newly involved stakeholders (such as government agencies who are responsible for maintaining reservoirs, floating structure manufacturers) on a single platform. The experience shared and solutions adopted will shape the future trajectory of floating solar PV in India.
- Mohit Acharya and Sarvesh Devraj (2019), ‘Floating Solar Photovoltaic (FSPV): A Third Pillar to Solar PV Sector ?’
- IRENA (2019), Renewable Power Generation Costs in 2018, International Renewable Energy Agency, Abu Dhabi