For those who are still unaware, India’s decades’ long fight against the ‘weed from hell’, or water hyacinth, shows no signs of ending. The South American pant, which made its way into the country decades ago, has spread so widely across water bodies in the country, that it is estimated to cover 0.2 million hectares of water bodies by some estimates.
The plant, characterised by its purple flowers and thick, waxy leaves, floats and grows well on still water. With the proliferation of dams, man-made lakes, and reservoirs for drinking water and more, besides the extensive use of fertilizers, especially nitrates, besides sewage, water hyacinths have enjoyed a period of conquest worldwide and in India.
Particularly detested for the damage they do to ecosystems, be it reducing oxygen in the water, thus killing off marine life, or choking drains and even sluice gates of dams and barrages, they have been a huge problem. As recently as 2017, Bengaluru’s iconic Ulsoor lake needed 7000 army men to clean up the lake’s hyacinth infestation, only for the same to come back again this year. ‘Weed from hell’, as you can see, is a well-earned sobriquet for this plant.
But now, among the many methods being used to combat it, which include mulching it to make fertiliser, paper, and many other applications, comes a really interesting one. Floating solar plants. By their very nature, floating solar plants, by cutting off access to direct sunlight for the plant, could potentially help control the menace in lakes where these plants are set up in. Typically recommended for use in not more than 1/3rd of the area of the water body where they are installed, by making the area under the panels safe from water hyacinths, the floating plant could go some way to protect a significant part of the larger water bodies affected by Hyacinths. By powering aerators or fountains in their vicinity, they can also help maintain the oxygen level in the water, helping save the fishes and other marine life inside the water.
With states across India, especially Kerala, Andhra Pradesh, Telangana and even Punjab increasingly looking to floating solar as an option to optimise the use of their vast water storage reservoirs and lakes, put that as a small, but green tick mark for floating solar.