With rising awareness about the perils of non-renewable energy, the world is making a strong push towards clean energy. One of the of biggest components of renewable energy generated across the globe is hydropower, that is, the energy produced from turbines driven by flowing water. As per Ministry of Power, this source supplies at least 50% of electricity production in 66 countries and more than 90% in 24 countries. In India, the share of hydro power is 12.2% of total energy generation.
As per Ministry of New and Renewable Energy (MNRE) the hydropower potential of India is around 1,45,000 MW and at 60% load factor, it can meet the capacity demand of around 85, 000 MW. With only 46000 MW of Hydropower potential exploited in India, we still have a long way to go.
Hydro power plants run between 35% to 50 % of the year of their full capacity. Run of the river projects have lower power generation potential as compared to those built with huge dams. Irrespective of the way the hydro plants are built to best exploit this source of renewable energy, there are multiple environmental repercussions associated with it. Every stakeholder needs to contemplate the impact hydropower generation would have on the environment, and the potential impact of dams on the climate change.
As per Intergovernmental Panel on Climate Change (IPCC) (a UN body) , the major greenhouse gases are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). These gases are emitted from natural aquatic habitats such as lakes, stagnant rivers, estuaries, wetlands and other terrestrial ecosystems like forests and soils. The hydropower dams have an ecosystem like these areas, due to which it emits Methane (CH4) and other Green House Gases.
IPCC further notes, that the global warming potential (GWP) of CH4 is 21 times higher than CO2 over a period of 100 years, revealing that CH4 is substantially more harmful than CO2 in the long run. In addition to the Methane, the dams storing water round the year also produce Carbon dioxide, and Nitrous Oxide from reservoirs, and catchment areas. However, mostly methane is generated by the decomposition of vegetation and by the microorganisms in the soil and population of fish submerged by the reservoirs, which then escapes into the atmosphere.
A research paper by renowned biologist Philip Fearnside revealed that hydropower dams located in tropical regions generate more methane than those located in temperate zones. The hot and humid climate of the area near the equator builds up an ecosystem that results in the formation and emission of the Greenhouse Gases (GHG). Another extensive study led by ecologist Bridget R. Deemer, on gas emissions from 267 large reservoirs world over, noted that more than 80 per cent of methane emissions come from water storage reservoirs created by dams, contributing almost three times more to global warming compared to carbon dioxide.
Apart from the fact that dams are multiplying the existing…