A hybrid system — renewable energy along with battery storage — will not only be cheaper than coal power but can also help reduce curtailment of renewable energy in Tamil Nadu, according to a study by Climate Trends and JMK Research and Analytics.

Tamil Nadu is a leader in renewable energy generation. But the State curtails a large percentage of this intermittent power due to many reasons, including excessive generation and concerns around grid imbalance. Since the lockdown in March 2020, Tamil Nadu has curtailed 50.8 per cent of solar power while its average curtailment of wind power in 2019 went up to 3.52 hours per day from 1.87 hours per day in 2018.

According to the study, a battery-based system can address the issue and cut the heavy losses to the renewable power developers, by storing and releasing the power after peak solar and wind generation hours. This hybrid system will also be a cheaper option than building new coal capacity to meet the growing power demand.

“Our analysis found that the cost of hybrid renewable energy with battery storage system is at parity with new coal power plants in Tamil Nadu. Moreover, in 10 years’ time, incremental capacity addition will further drive down the cost by over 31 per cent,” said Jyoti Gulia, founder of JMK Research and Analytics. The report has found that the levelised cost of energy for a hypothetical hybrid, solar, wind and li-ion battery storage system for Tamil Nadu is estimated at ₹4.97/kWh in 2021, which falls to ₹3.4/kWh by 2030. In comparison, cost of electricity produced from new coal power plants in the State is in the range of ₹4.5-6/kWh.

Tamil Nadu has five new thermal power projects in its pipeline over the next three years. The Cheyyur ultra mega coal power plant is the biggest of these projects with a tariff of ₹5-6/kWh, which would be 32-43 per cent more expensive than the system modelled in the analysis.

“Tamil Nadu has got the largest installed renewable energy capacity and it leads India’s energy transition efforts, yet it also has the largest coal power pipeline in the country. Since RE with battery storage works out to be cheaper than coal, perhaps Tangedco and other State power generation companies need to reconsider the coal pipeline” said Aarti Khosla, Director, Climate Trends.

Growing market

Meanwhile, a few studies have indicated that the energy storage market will continue to grow during this decade. The most popular battery technologies for energy storage include flooded lead-acid batteries, valve regulated lead acid batteries (VRLA), lithium-ion batteries and other technologies such as flow batteries and thermal batteries.

However, penetration of lithium-ion batteries would see rapid growth in the storage market in view of falling prices of lithium-ion battery systems.

Published on January 24, 2021