India has done a remarkable job in terms of deployment of renewable energy-based installations, growing almost 3.5 folds in the last 5 to 6 years, with most of the capacity coming from onshore wind and solar photovoltaic (PV) based installations. At present India’s grid-connected solar PV sector is majorly dominated by the ground-based installations (93%) while the balance is contributed by rooftop based solar PV installations. The installation cost of utility-scale solar PV in the country has declined by 84%2 between 2010-2018, making India world’s topmost country in achieving the lowest installation cost for utility scale solar PV. It is well know that solar PV deployment is quite land intensive and scaling up the project sizes requires large chunk of contiguous land parcels, which becomes challenging in many situations.
In order to keep pace of development commensurate with the national targets for solar capacity additions, alternatives are required to be explored and established. Floating solar PV (FSPV) or floatovoltaics is one such alternative, which has started getting traction worldwide and is expected to grow strongly over the coming years. It is estimated that the annual capacity addition may rise from the current installed of 1.314 GWp in 2018 to 4.6 GWp by 2022. Presently, China is the leading international market followed by Japan and South Korea. India also has very bright prospects to develop FSPV projects due to availability of large water bodies.
As a technology, FSPV is in a very early stage of development in India. Till now, only a few projects with cumulative capacity of 2.7 MW have been installed. However, over 1.7 GW capacity projects are reported to be in various stages of development. FSPV market appears to inch forward to make its presence felt in India and the tariffs discovered through bids have already shown rapid reductions. So far large-to-medium size man-made inland water bodies seems to have attracted initial interest to install FSPV based power plants, but all these water bodies were created to serve various purposes like – irrigation, water supply, fishing, hydroelectric, navigation, etc., and this warrants great deal of diligence to balance out various usages of these water bodies on the basis of accurate information.
According to a research study jointly conducted by The Energy and Resources Institute (TERI), New and the Energy Transitions Commission (ETC), India, has about 18,000 km2 water surface area spread across various states and UTs suitable for the installation of FSPV plants. The overall potential is a strong indication of the extent of the surface area than can be made available for setting up these projects, and even a capacity of about 280 GW is possible.
Globally the technology is currently deployed in more than 24 countries across the entire world with the majority of installations in Asia, particularly in Japan, China, and South Korea. The FSPV technology has been able to gather a lot of traction in the past 3 years (2016, 2017 and 2018) globally. The total installed capacity now stands at 1314 MWp, which is further going to increase substantially in the years to come and expected to reach 4600 MWp by 2022, thanks to the recent increase in the activities in the sector in countries like China. Majority of installations till date are deployed on man-made waterbodies such as irrigation dams, industrial basins, water treatment plants, and unused mining ponds.
The FSPV as a technology is still in the nascent stages of development in India. The journey started with a 10kW FSPV plant on a pond in Rajarhat, Kolkata in 2015. The project was part of a research activity sponsored by the Ministry of New and Renewable Energy (MNRE). In 2016, NTPC installed country’s largest 100kW plant on a reservoir of its combined cycle power plant situated in Kerala’s Kayamkulam district. Later in December same year, Kerala State Electricity Board started its operation of 500kW plant at Banasura Sagar reservoir in Wayanad district replacing NTPC’s 100kW as a largest FSPV-based plant. The plant is actually a scaled-up version of the 10kW plant commissioned in January 2016 at the same location. The plant was able to bring some confidence to FSPV promoters by successfully surviving the recent flood ravage in the state. The recently commissioned 2MW project at Visakhapatnam, Andhra Pradesh has now the largest FSPV-based plant commissioned in the country till date and with this the total installed capacity of FSPV has becomes 2.7 MW. The FSPV sector is now getting a lot of attention in the country, which can be seen via an increase in the numbers of tenders that are released in the past 2 years. At the moment there is more than 1700 MW worth of projects, which are in various stages of development and more are in pipeline making the outlook very positive for this new segment.
The FSPV sector is evolving very rapidly and is likely to become an alternate popular way to generate solar energy very soon. However, very little know-how is available at the moment thus posing many challenges, which need to be addressed properly. Some of the key challenges associated with the FSPV are presented below.
Challenges Associated with Floatovoltaics
- Unavailability of FSPV-specific standards / technical guidelines:
Since FSPV as a technology is still in its nascent stages, there are no specific standards/technical guidelines available at the moment. Unlike the ground-based solar PV projects, an FSPV project comprises floating platform and anchoring and mooring systems placed on top of the water surface. To ensure that these components can withstand harsh environmental conditions while retaining the quality over 25 years without causing any serious impact on local biodiversity it is important to formulate FSPV component specific standards and technical guidelines for designing such plants.
- Unavailability of waterbody data:
The waterbody data availability is a crucial parameter in estimating the actual potential and designing of FSPV. The current usage of waterbodies, types of waterbodies, and their ownership are also not defined.
- FSPV plant components safety and its long-term reliability:
An FSPV plant’s electrical and electronic components are constantly exposed to harsh environmental conditions such as high humidity, salinity of water, high wind speed, etc. Hence unlike ground-based solar PV, long-run risks of operation could be relatively high in case of FSPV plants. Additionally, components like floating platform, solar PV module, cables, etc., float upon the water surface, therefore, there might be a possibility that these components are prone to degradation, corrosion, and bio-fouling. Unexpected behaviour of these components not only has the potential to increase the O&M cost but also can cause serious safety issues jeopardizing the life of the personal operating the plant. However, till now, there is no such study that can highlight the long-term reliability of these components.
- Absence of local manufacturing:
Till now there are very few local manufacturers that have developed capabilities of providing floating platform and anchoring and mooring system. establishing local manufacturing market through appropriate policy support will not only help in bringing down costs but shall aid in developing the local market capabilities as well.
- Installation Challenges:
Presently, the guidelines/checklists are only available for ground-based solar PV projects and there is no information on what kinds of clearances are needed in the case of FSPV plants.
Often waterbodies are available in remote places and surrounded by mountainous range, forest areas, etc., making the accessibility difficult. Transportation of floats to remote places can add extra cost to the project. Also, establishing manufacturing units of floats near the project locations could pose some challenges and largely dependent on the project location and capacity of the plant.
- O&M Challenges:
Since FSPV plants are installed on the water surface rather than on land, it is relatively difficult to deal with O&M issues in such conditions. There are certain parts like anchoring and mooring that lie inside the water and are required to be inspected on a regular basis to ensure the plant’s stability.
Also sudden fault, instances like of bird dropping, replacement of electrical parts, maintenance of cables and wires, etc., are complex things to handle and require special training to plant personnel.
FSPV looks promising to become a third pillar of the solar PV sector and its market share is likely to accelerate. It provides some inherent advantages like improvement in energy yield due to evaporative cooling effect because of vicinity to the water surface, alternate to land use (land neutrality), potential to use the existing power infrastructures, potential to save water evaporation loss, etc. However, FSPV is in nascent stage of its development in India and there are lots of questions particularly regarding its long-term impact on the local environment and bio-diversity which require answers before rushing into large scale deployment. Formulation of FSPV-specific standards and project development guidelines is the need of the hour and is of vital importance to reap the actual benefit of this technology without causing any negative impact on the local environment.
(This article derives its content from the study conducted by TERI and Energy Transition commission and the report published under the heading Floating Solar Photovoltaic (FSPV): A Third Pillar to Solar PV Sector?. The intended purpose of this article is to update and educate the professionals from the solar pv sector about the opportunities and challenges for floating solar PV in India)