Tamil Nadu's Wind Energy Potential and the Challenges of Repowering

Tamil Nadu, one of India's pioneering states in wind energy generation, has long been a leader in installing wind turbines. However, many of its wind turbines, some over 30 years old, are becoming less efficient, prompting the state government to introduce the “Tamil Nadu Repowering, Refurbishment and Life Extension Policy for Wind Power Projects - 2024” to address the issue. However, the policy has faced opposition from wind energy generators, who have approached the Madras High Court, highlighting concerns that the policy does not adequately promote wind energy generation.

Wind Energy Capacity and Potential in India

• India is one of the leading countries in the world for wind energy, ranking fourth globally for installed wind energy capacity.
• According to the National Institute of Wind Energy (NIWE), India has the potential to generate up to 1,163.86 GW of wind power at 150 meters above ground level.
  • At the more typical turbine height of 120 meters, the wind energy potential stands at 695.51 GW, of which 68.75 GW is from Tamil Nadu.
• Currently, India is harnessing only about 6.5% of its wind potential at the national level, with Tamil Nadu utilizing around 15% of its own wind energy potential.
  • The states of Gujarat, Tamil Nadu, Karnataka, Maharashtra, Rajasthan, and Andhra Pradesh collectively contribute 93.37% of India’s installed wind energy capacity.
  • Tamil Nadu, in particular, has been a major contributor to India’s wind energy capacity.
    • With over 10,600 MW of installed wind energy capacity, it holds the second-largest installed wind power capacity in the country, behind Gujarat.
    • However, much of the state's wind capacity consists of small turbines (less than 1 MW), some of which are over 30 years old.

What Is Repowering and Refurbishing?

• Wind turbines have a finite lifespan, and many older turbines, particularly those installed before 2000, are becoming inefficient. To address this, the wind energy sector employs two key processes:
• Repowering: This involves replacing old, small-capacity turbines with newer, larger-capacity ones. For example, turbines that are less than 2 MW in capacity can be replaced with turbines that have a capacity of 2 MW or more. Repowering can increase the power output of a site and improve efficiency.
• Refurbishing: This process involves upgrading existing turbines without replacing them entirely. Refurbishment can include replacing blades, increasing the height of the turbines, or installing more powerful gearboxes, thus enhancing the energy generated.
• Life Extension: Older turbines that are still operational but have reduced efficiency can be given a life extension by updating components or improving safety measures to extend their operational lifespan.
• The Ministry of New and Renewable Energy (MNRE) and National Institute of Wind Energy (NIWE) have estimated that repowering has the potential to generate an additional 25.4 GW if smaller, underperforming turbines (less than 2 MW) are replaced or refurbished.