Idukki Hydroelectric Project at 50: Five Decades of Powering Kerala’s Growth

Why in the News ?

The Idukki Hydroelectric Project, Kerala’s largest hydel power project, has completed 50 years of operation. Over five decades, the Moolamattom underground power plant has generated 115,852.672 million units (MU) of electricity, marking a historic milestone in India’s hydroelectric development.

Background and Context

Hydroelectric power has been central to Kerala’s energy strategy due to:

• Abundant rainfall
• Western Ghats’ topography
• Numerous west-flowing rivers

The Periyar River, Kerala’s longest river, provides the foundation for the Idukki project. Conceived in the mid-20th century and commissioned in the 1970s, the project aimed to address:

• Rising electricity demand
• Industrial expansion
• Agricultural electrification
• Urbanisation in Kerala

At a time when India was focusing on large multipurpose river valley projects, Idukki emerged as a landmark engineering achievement in southern India.

About the Idukki Hydroelectric Project

• Location: Across the Periyar River in Idukki district, Kerala
• Type: Hydroelectric power project
• Operator: Kerala State Electricity Board (KSEB)
• Status: Largest hydroelectric project in Kerala

The project consists of three dams:

1. Idukki Dam
2. Cheruthoni Dam
3. Kulamavu Dam

Together, they create a large reservoir system to facilitate power generation.

Engineering and Structural Features

1. Idukki Arch Dam

• One of the highest ten arch dams in the world.
• Third highest in India after:
  • Tehri Dam
  • Bhakra Nangal Dam
• First dam in Asia constructed as a double-curvature arch dam.
• Second such dam in the world.

2. Moolamattom Powerhouse

• Houses the underground power station.
• The longest underground power station in India.
• Contains the largest pressure shaft in the country.

The underground design enhances:

• Structural stability
• Security
• Efficient energy conversion

Power Generation and Performance

Over 50 years, the Moolamattom power plant has:

• Generated 115,852.672 million units (MU) of electricity.
• Played a crucial role in stabilising Kerala’s power supply.

Hydropower remains vital for:

• Peak load management
• Grid stability
• Renewable energy contribution

Although Kerala now supplements hydropower with thermal and renewable sources, Idukki remains a backbone of the state’s energy infrastructure.

Significance of the Idukki Project

1. Energy Security for Kerala

The project significantly reduced dependence on imported power and fossil fuels, ensuring stable electricity supply.

2. Renewable and Clean Energy

Hydropower contributes to:

• Low carbon emissions
• Climate-friendly energy mix
• Support for India’s net-zero goals

3. Engineering Excellence

The double-curvature arch dam design and underground powerhouse represent milestones in Indian civil engineering.

4. Economic Development

Reliable electricity has supported:

• Industrialisation
• IT sector growth
• Tourism
• Agricultural productivity

5. Strategic Role in Flood Control

While primarily a power project, the reservoir system also aids in:

• Water regulation
• Flood moderation during monsoons

Challenges and Way Forward

Challenges

• Aging infrastructure after five decades
• Sedimentation in reservoirs
• Climate variability affecting rainfall patterns
• Environmental and ecological concerns

Way Forward

• Modernisation and technological upgrades
• Strengthening dam safety audits
• Integrating hydropower with solar and wind energy
• Enhancing climate resilience measures
• Promoting sustainable reservoir management