Context

Recent droughts in Colombia and Ecuador have severely hampered energy supplied by hydropower generation.

Vulnerability of Hydropower Generation

• Climate Vulnerability of Hydropower: The resulting power shortages have highlighted the vulnerability of hydropower in the face of climate change.
• Impact of Drought: A drought fueled by the El Nino weather phenomenon has reduced reservoir water levels in hydropower plants, which both countries rely on for most of their electricity.  
  • This has led Ecuador to declare a state of emergency and institute power cuts. 

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Hydropower Generation

Hydropower, or hydroelectric power, is a renewable source of energy that generates power by using a dam or diversion structure to alter the natural flow of a river or other body of water.   

• • Hydropower relies on the constantly recharging system of the water cycle to produce electricity, using a fuel—water—that is not reduced or eliminated in the process. 
• Mechanism: Hydropower functions by harnessing the movement of water flowing through a turbine, which generates electricity as it spins.
• Current Dominance in the Clean Energy Sector: Hydropower has evolved into a crucial clean energy source due to its reliability, affordability.
• Classification of Hydro Projects based on Installed Capacity: Hydro power projects are generally categorized in two segments i.e. small and large hydro. 
• In India, hydro projects up to 25 MW station capacities have been categorized as Small Hydro Power (SHP) projects.
  • Micro: upto 100 KW
  • Mini: 101KW to 2 MW
  • Small: 2 MW to 25 MW
  • Mega: Hydro projects with installed capacity >= 500 MW

Advantages of Hydropower

• Reliable: Hydropower is needed to stabilize electricity generation, providing power when wind and solar can’t.
• Renewable Source: It is a renewable source of energy with no consumables involved; 
• Little Recurring Cost: There is very little recurring cost and hence no high long term expenditure. It is cheaper as compared to electricity generated from coal and gas fired plants.
• Ideal for Peak Load Management: Hydropower stations are a preferred solution for meeting peak loads in grids due to its unique capabilities of quick starting and closing.

Challenges to Hydropower Sector

• Capital Intensive: The hydropower generation is a highly capital-intensive mode of electricity generation.
• Environmental Impact: Submergence of land, thereby loss of flora and fauna and large scale displacement, due to the hydropower projects.
• Dependency on Water: Hydropower is dependent on water and its shortage disrupts energy production and stressing energy systems.
• Climate change: Droughts and sudden floods which can damage dams have been made more frequent and severe by climate change. Thus, it is an “increasing concern” for hydropower.
• Over-reliance increases climate vulnerability:  Countries with a high dependence on hydropower are particularly vulnerable to climate impacts.

Global Scenario Hydropower Generation

• 2023 saw a Historic drop in Hydropower: According to Ember, a UK based energy think tank, in the first half of 2023 the global output of hydropower saw a historic drop in 2023.
  • Drought conditions, potentially exacerbated by climate change, resulted in an 8.5% decline in global hydroelectricity production during this period.
• Impact of Drought on China’s Hydroelectricity Generation: China, the world’s largest hydroelectricity generator, accounted for three quarters of the global decline.
  • During 2022 and 2023, droughts resulted in Chinese rivers and reservoirs drying up, leading to power shortages and necessitating electricity rationing in the country.

Way Forward: Diversified and Resilient Renewable Energy

• Diversification of Energy Mix: The climate vulnerable countries need to diversify their power sources by incorporating other renewable technologies such as wind and solar into their energy mix.
  • Ghana and Kenya are successfully moving from high reliance on hydropower towards a more “robust portfolio of technologies”.
• Exploring the Potential of Floating Solar Panels in Hydropower Plants: Placing floating solar panels on the water’s surface in hydropower plants have significant potential. Ex- China and Brazil are exploring them.
• Focusing on Medium scale Plants: Despite the climate-risks associated with the technology, it is still considered significant in decarbonizing the global economy because it can provide cheap power at large scale.
• Building more medium scale plants, rather than the mega dams, would help mitigate the climate-risks associated with overdependence on one big dam.
• Enhancing Hydropower Resilience: Improved water management within basins and strategic integration of hydropower plants with other renewable sources can enhance resilience to drought.
• Pumped-storage hydropower systems: These pump water uphill during periods of low electricity demand and release it downhill during peak demand. 
  • These systems have minimal water consumption as they recycle water. While not entirely immune to drought, they are more resilient compared to conventional hydropower schemes.

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Conclusion

While climate change is going to increase the risks for hydropower, better management of water within a basin and how plants are integrated with other renewables can improve resilience to drought.

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