TN is rich in renewable energy, with a large capacity of both existing installations and projects in the pipeline. The state is transitioning to higher shares of RE. The International Energy Agency (IEA) Flagship Report on Energy Technology Perspectives 2020 (IEA 2021a) identifies advances in technology, speed of innovation, and scalability of new technologies as important variables determining the pace of the energy transition. This study provides insights into TN’s energy mix and explores suitable technologies that the state can consider for its energy transition. Information on Technology Readiness Levels (TRLs) and many other aspects of different renewable/clean energy options for electricity generation are provided that could be relevant for effecting its energy transition.

This paper explores electricity generation technology options for the sustainable energy transition of TN. Renewable and clean energy options such as wind (onshore, offshore, small wind), solar PV, bioenergy, energy storage, and green hydrogen are selected, considering the available renewable resources in the state and the projected installation or market potential. The paper describes the current landscape of these renewable options in the state by looking at multiple aspects such as installed capacities, targets, technologies used, developments, policies, and barriers. Further, technology innovations and developments that are available now and those that will likely reach maturity over the coming years are reported. Barriers to the adoption of these technologies, along with information on the related stakeholders, are also described.

Key Findings:

  • There is significant market potential for repowering because many of the wind turbines installed during the 1990s are reaching—or are close to reaching—the end of their stipulated lifecycles. To be specific, the immediate repowering potential in TN is 834 megawatts (MW), with a further 3,979 MW by 2027. This repowering can also enhance the overall RE capacity and generation because the replacement wind turbines available today have a higher rating and efficiency. The technologies and supply chains needed to repower onshore wind farms are available.1 Policies and guidelines that address many of the challenges associated with repowering need to be instituted.
  • Offshore wind is another sector with market potential that has high-TRL technologies which have been successfully deployed in other countries. The supply chains still need to be developed for the Indian offshore industry, alongwith port infrastructure and other requirements. This is considering India’s first upcoming tender for a 4 gigawatt (GW) offshore wind project off TN’s coast.
  • Different solar PV technologies have reached various stages of development, with TRLs ranging from 4 to 10. The market potential for solar PVs is also high considering TN’s capacity addition plans (20 GW). The share of monocrystalline is increasing; however, other newer technologies offering higher efficiencies are costly and will likely require policies to promote their installation.
  • BESS technologies are already being commercially deployed, and economies of scale are helping drive down costs for the most popular options. The market potential of BESS is expanding, fueled by the rising share of variable RE. A BESS capacity of about 10 gigawatt-hour (GWh) is planned over a period of 10 years in TN.
  • Green hydrogen is another fuel that is being considered as a possible alternative energy option. The required technologies are being validated in the laboratory and tested in practical settings. The National Hydrogen Mission is focused on producing 5 million metric tons (MMT) of green hydrogen by 2030. The TRL for the production of green hydrogen through proven technologies such as alkaline and polymer electrolyte membrane electrolyzers is 7–9. Thus, an immediate benefit can be obtained by replacing the existing fossil-fuel-based hydrogen utilized in industries such as fertilizers and refineries with green hydrogen. Incorporating green hydrogen into other hard-to-abate sectors such as steel and cement needs further assessment because the TRLs for these new processes are not high enough and state-level policies and roadmaps are limited or being developed. TN has been selected for setting up green hydrogen valleys for green hydrogen manufacturing and potential supply to suitable industries.
  • Bioenergy technologies with high TRLs and supply chains are available, but regulatory support is required. The viability of community plants needs re-investigation in light of the availability of newer technologies, and policies can be developed that focus on this. Additionally, cogeneration power plants with an installed capacity of 90 MW are under way in TN.
  • Many of the technologies outlined in this paper are largely proven in the Indian context and are therefore prime candidates for further deployment. However, stakeholder support is essential to facilitate the development of markets and the related ecosystems. Support is also needed to formulate policies and regulations.