- Global Hydropower potential
- Hydropower potential of India
- Hurdles against hydropower projects
- Hydropower projects: their impact on the environment
- Climate Change and Vulnerability of Hydropower
- What should be done?
To access IASToppers Quintessence of Magazines Archive, Click here
GS (M) Paper-3: “Infrastructure: Energy”
GS (M) Paper-3: “environmental pollution and degradation”
- Recently, the ‘World Conference on Environment-2017’ was held in New Delhi.
- At this conference, India reiterated its commitment to the Paris Climate Change Agreement and stated that the country will have 225 Gigawatts (GW) of renewable and clean energy sources by 2022.
Global Hydropower potential:
- Several countries, in order to mitigate climate change, have turned to exploring hydropower sources.
- According to the World Energy Council, Hydropower is the leading renewable source for electricity generation globally, supplying 71% of all renewable electricity.
- Reaching 1,064 GW of installed capacity in 2016, it generated 16.4% of the world’s electricity from all sources.”
- China tops the world’s hydropower capacity with 319 GW, followed by the United States with 102 GW. India stands fourth with 52 GW.
Hydropower potential of India:
- India is the 7th largest producer of hydroelectric power in the world ranking third worldwide in the total number of dams.
- India’s economically exploitable and viable hydroelectric potential is estimated to be 148,701 MW.
- India’s hydroelectric power potential is estimated at 84,000 MW at 60% load factor.
- An additional 6,780 MW from smaller hydro schemes (with capacities of less than 25 MW) is estimated as exploitable.
- So far, around 26% of Hydropower potential has been exploited in India.
- Maximum potential is in the state of Arunachal Pradesh. It has 33% of the total hydroelectric potential of India.
- The public sector accounts for 92.5% of India’s hydroelectric power production.
- The private sector is also expected to grow with the development of hydroelectric energy in the Himalayan mountain ranges and in the northeast of India. Indian companies have also constructed hydropower projects in Bhutan, Nepal, Afghanistan, and other countries.
- It is noteworthy that India became a net exporter of electricity for the first time between April 2016 and February 2017, exporting around 5,585 million units to Nepal, Bangladesh and Myanmar.
Hurdles against hydropower projects:
- 16 of the 43 hydropower projects currently under construction are stalled for various reasons.
- The CAG, in its report tabled in March 2017, found that the standard procedures including for environmental impact assessments and public hearings have been bypassed.
- In central India, the hydroelectric power potential from the Godavari, Mahanadi, Nagavali, Vamsadhara and Narmada river basins has not been developed on a major scale due to potential opposition from the tribal population.
Hydropower projects: their impact on the environment
Though hydropower is a clean source of energy, yet it can have a serious negative impact on the climate.
According to various studies,
- Significant amounts of carbon dioxide, nitrous oxide and methane are emitted from reservoirs, turbines and spillways.
- Methane alone accounts for 104 million metric tonnes of all these emissions annually.
- Mostly, methane is generated by the decomposition of vegetation and soil submerged by the reservoirs.
- Hydropower dams located in tropical regions generate more methane than those located in temperate zones.
- Although methane in the atmosphere stays for only a short while compared to carbon dioxide, 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.
Although the findings of hydropower’s contribution to GHG emissions remain consistent, none of these emissions are included in global greenhouse inventories.
Climate Change and Vulnerability of Hydropower:
- Climate change by altering the river discharge impacts the availability of water resources, water regularity and hydropower generation.
- Water is constantly replenished by a process of hydrological cycle in the atmosphere, but this cycle could get altered due to climate change.
- Floods, droughts, changes in temperature, precipitation and melting glaciers are all symptoms of climate change. Since the amount of electricity a hydropower plant can produce directly depends on the availability of water resources, lower the river discharge, lesser the power generation.
- Major rivers like the Indus, Ganga and Brahmaputra are fed by snow and glacier melt. But the retreat of glaciers in the Himalayas is likely to alter the pattern of river flow, resulting in the disruption of hydropower production.
- A 1 % reduction in the flow can reduce electricity output by roughly three per cent.
- Moreover, one cannot ignore the economic risks of investing in a hydropower project under the prevailing conditions of climate change.
What should be done?
- The social impact of large dams by way of population displacement and loss of income from farming and livestock should also not be overlooked.
- While hydropower projects are critical for economic growth and development, it is equally important to fully assess its potential social and environmental impact in the long-term.
- The challenge lies in finding the right balance between the need for rapid development and the necessity of protecting the environment.
Minister of State for Power, Coal, New & Renewable Energy and Mines, Piyush Goyal had rightly observed that “it is time that human beings understand that climate change is a challenge caused by humans, and ultimately it is humans who can address it.”