Tamil Nadu's Solar Revolution: Battery Storage Lights the Way to Green Power

The initiative, seen as a breakthrough in the State's clean energy transition, comes four years after the state government announced an ambitious plan to set up 20,000 MW of solar capacity and 10,000 MW of battery storage within a decade.

In a landmark order, the Tamil Nadu Electricity Regulatory Commission (TNERC) has permitted the Tamil Nadu Green Energy Corporation Ltd (TNGECL) to float tenders for two grid-connected solar power projects with battery energy storage systems (BESS). Each project, with a 15 MW solar capacity and 45 MWh storage, will come up in Karur and Tiruvarur districts and will be operated on a build-own-operate model for 25 years.

According to TNGECL, these hybrid projects are designed to meet the State's growing evening peak demand, which solar energy alone cannot handle.

Tamil Nadu's peak power requirement is expected to rise from 19,409 MW in 2023-24 to over 27,500 MW by 2029-30, while annual energy demand could almost double by 2034-35. Though Tamil Nadu already has more than 10,800 MW of solar power capacity, production remains confined to daylight hours, forcing the utility to buy high-cost power from exchanges during the evening.

With battery storage, the new projects will enable time-shifting of solar generation to peak hours, reducing both costs and dependence on thermal power. The combined capital investment for the two projects is pegged at around Rs 200 crore, with a projected levelised tariff of Rs 6.49 per unit -- considerably lower than peak exchange prices that can touch Rs 10 per unit. Over 25 years, the projects are expected to save about Rs 90 crore for Tamil Nadu Power Distribution Corporation Ltd (TNPDCL) compared to market purchases.

Land has been identified for the projects at K. Pitchampatti in Karur and Korukkai in Tiruvarur. Once commissioned, they will provide a steady renewable energy supply during evening hours and position Tamil Nadu as a frontrunner in dispatchable green power.

Officials said the initiative marks the beginning of Tamil Nadu's transition toward flexible, storage-backed renewable generation. "These projects will serve as a learning platform for large-scale integration of battery systems in the State grid and pave the way for future investments in round-the-clock green energy," a senior TNGECL source said.

- IANS