Definition and Importance
Natural resources are materials or substances that occur in nature and can be used for economic gain or human benefit with minimal modifications. These resources are essential for various purposes including commercial and industrial use, aesthetic value, scientific interest, and cultural significance.
Examples: Sunlight, atmosphere, water, land, minerals, vegetation, and wildlife.
Types and Classifications
♻️ Renewable Resources
Resources that can be replenished naturally over time, such as sunlight, wind, and biomass.
⚠️ Non-Renewable Resources
Resources that cannot be replenished once depleted, such as fossil fuels, minerals, and metals.
Examples of Natural Resources
- 💧 Freshwater: Essential for drinking, agriculture, and industry
- 🌬️ Air: Vital for all aerobic life forms
- 🐟 Living Organisms: Fish, forests, and wildlife
- ⛏️ Extracted Resources: Metal ores, rare-earth elements, petroleum, timber, and energy
Economic and Political Implications
The allocation and extraction of natural resources are often central to economic and political conflicts. Scarcity and overconsumption can lead to confrontations within and between countries. Resource extraction has also been linked to human rights violations and significant environmental damage.
Sustainable Management and Development
The Sustainable Development Goals (SDGs) emphasize the need for sustainable resource extraction. Efforts are being made to develop economic models that reduce reliance on resource extraction.
Key Models: Circular economy focusing on reuse, recycling, and sustainable management of renewable resources to ensure availability for future generations.
Water, being about 800 times denser than air, can generate substantial amounts of energy even from a slow-flowing stream or moderate sea swell. Water can generate electricity with a conversion efficiency of about 90%, the highest rate among renewable energy sources.
🏗️ Large Hydroelectric Dams and Reservoirs
Historically, hydroelectric power has been generated by constructing large dams and reservoirs.
Examples: Three Gorges Dam (China), Itaipu Dam (Brazil and Paraguay)
⚡ Small Hydro Systems
These installations typically produce up to 50 MW of power and are often used on small rivers or as low-impact developments on larger rivers.
Global Leader: China leads with more than 45,000 small hydro installations
🌊 Run-of-the-River Hydroelectricity
These plants derive energy from rivers without creating large reservoirs. Water is conveyed along the side of the river valley using channels, pipes, or tunnels until it is high above the valley floor, then allowed to fall through a penstock to drive a turbine.
Example: Chief Joseph Dam on the Columbia River (United States). Many run-of-the-river plants are micro or pico hydro plants.
Advantages and Challenges
✅ Flexibility
Hydropower is highly flexible and can complement wind and solar power. As of 2021, the global renewable hydropower capacity was 1,360 GW. However, only a third of the world's estimated hydroelectric potential of 14,000 TWh/year has been developed.
⚠️ Challenges
New hydropower projects often face opposition from local communities due to their large impact, including the relocation of communities and flooding of wildlife habitats and farming land. High costs and long lead times due to the permission process, including environmental and risk assessments, and the lack of environmental and social acceptance, are primary challenges for new developments.
🔄 Repowering and Upgrading
It is popular to repower old dams to increase their efficiency and capacity and improve their responsiveness on the grid. For example, existing dams like the Russell Dam, built in 1985, may be updated with "pump back" facilities for pumped-storage, useful for peak loads or to support intermittent wind and solar power.
Economic and Environmental Considerations
💡 Value of Dispatchable Power: Dispatchable power (power that can be turned on or off as needed) is more valuable than variable renewable energy (VRE) sources like wind and solar.
Countries with large hydroelectric developments, such as Canada and Norway, are investing billions to expand their grids to trade with neighboring countries that have limited hydro resources.
Water energy, through various forms of hydropower, plays a crucial role in renewable energy production. While large-scale projects have been the traditional focus, small and run-of-the-river systems offer significant potential with lower environmental impacts. Addressing challenges such as community opposition, high costs, and long lead times is essential for the continued expansion and optimization of hydropower.
🇮🇳 Global Standing and Capacity
India is ranked 5th globally for installed hydroelectric power capacity. As of 31 March 2020:
Installed Utility-Scale Hydroelectric Capacity:
46,000 MW (12.3% of total utility power generation capacity)
Smaller Hydroelectric Units:
Total capacity of 4,683 MW (1.3% of total utility power generation capacity)
Total Hydroelectric Potential:
Estimated at 148,700 MW at a 60% load factor
📜 Historical Context
The hydroelectric power plants at Darjeeling (1898) and Shivanasamudra (1902) were among the first in Asia, marking India's early involvement in global hydroelectric power development. India also imports surplus hydroelectric power from Bhutan.
Categories of Hydropower
Small Hydropower
Facilities with nameplate capacities up to 25 MW
Managed by the Ministry of New and Renewable Energy (MNRE)
🔹 Large Hydropower
Facilities above 25 MW
Managed by the Ministry of Power
⭐ Largest Hydroelectric Plant
Koyna Hydroelectric Project
With a capacity of 1,960 MW
📊 Recent Performance and Challenges
Fiscal Year 2019-20
- • Total Hydroelectric Power Generated: 156 TWh (excluding small hydro)
- • Average Capacity Factor: 38.71%
Fiscal Year Ending March 31, 2024
- • Decline in Hydroelectric Output: 16.3% drop, the largest decline in 38 years due to low rainfall
- • Hydroelectricity's Share: Fell to a historic low of 8.3%
- • Generation: Reached a five-year low of 146 billion kWh
- • Increased Reliance on Coal: Due to the shortfall in hydroelectric power
- • Weather Influence: Lightest rainfall since 2018, potentially influenced by El Niño
🔮 Implications and Future Outlook
The decline in hydroelectric power generation highlights the vulnerabilities and challenges posed by erratic weather patterns. This has led to a diminished role for hydroelectric power in India's energy mix and increased reliance on coal.