Solar dreams on lake waters: experts warn of disturbance to aquatic ecosystem

The Hindu

3 days ago

The government's ambitious project to harness renewable energy by setting up floating solar panels on lakes has gathered pace, even as experts and limnologists flag its possible negative impact on the aquatic ecosystem.
The Minor Irrigation and Groundwater Development Department and Renewable Energy Department Limited have planned to install solar panels on 40 lakes in Kolar, Chickballapur, and Bengaluru. The project aims to generate up to 2,000 MW of energy.
'This innovative project is not just about energy; it also helps reduce lake maintenance costs, boosts fisheries, and protects against encroachments,' said the Energy Department.
However, experts have pointed out several drawbacks and suggested alternative approaches for consideration.
Shivakumar Magada, professor of aquatic biology at the College of Fisheries, Mangaluru, said the project could accelerate the degradation of lakes already affected by silt, urbanisation, and industrialisation.
'The lake's natural vegetation will be impacted by the introduction of a foreign body, disturbing the aquatic ecosystem. Weeds may also begin to grow owing to the accumulation of nutrients around the scaffolding for the panels,' Prof. Magada explained.
A limnologist and former pollution control board member, speaking on the condition of anonymity, argued that the panels could obstruct sunlight from entering the water, thereby limiting the growth of phytoplankton and zooplankton, both of which are essential food sources for fish.
Priyanka Jamwal, Programme Leader and Senior Fellow at the Water and Society Programme, noted that India's lakes are vastly different from those in other countries. Therefore, the approach to installing solar infrastructure should be tailored to Indian conditions.
Ms. Jamwal acknowledged a potential upside to the project and proposed a technique that could enhance lake health. She suggested that while installing the panels, project implementers should identify nitrogen and phosphorus hotspots within the lake and target those areas for panel placement.
'In nitrogen and phosphorus hotspots, lakes experience algal blooms when exposed to sunlight. If solar panels block sunlight in these areas, it could effectively prevent algal blooms,' Ms. Jamwal explained. However, she stressed that this is merely a hypothesis and that a pilot study is necessary to determine whether the approach will succeed or fail.
R. Anjaneya Reddy, president of the Shashwata Neeravari Horata Samiti, stated that the project should only proceed if there is assurance that the lake's natural state will remain undisturbed. 'Many birds and animals depend on these lakes as water sources. The government must ensure that none of them are adversely affected by the project,' Mr. Reddy said.
He also cautioned that catchment areas must remain unblocked and that local fishermen who rely on these waterbodies for their livelihood should be consulted and included in the decision-making process.
Ms. Jamwal echoed this sentiment, emphasising that the government must secure the support of the fishing community before moving forward with the project.
Mr. Magada proposed an alternative, suggesting that the government consider barren lands where farmers are willing to lease or sell fields for solar panel installations. He also recommended using Category E lakes, such as Nagawara and the western part of Hebbal lake, for the project, rather than selecting lakes classified under categories A, B, C, or D.
Lakes are categorised from A to E, with Category E referring to waterbodies deemed unfit for drinking and bathing.
The Energy Department claimed that it had conducted a feasibility study and is prepared to install solar panels on 40 lakes. However, repeated calls to officials seeking the results of the study went unanswered.