Energetica India Magazine October-November 2021

How New Technologies Could Enable Tamil Nadu to Transition to Cleaner Energy RENEWABLE POWER Surplus RE power can be utilized to produce green hydrogen which in turn can be used for multiple applications. Currently, there is no operational grid scale battery storage plant or hydrogen storage facility in Tamil Nadu. This is certainly an area that needs focus, especially with the state’s plans to increase RE capacities. 38 energetica INDIA- Oct-Nov_2021 Tamil Nadu has the highest capacity of installed wind energy in India (9.6 GW as of March 2021 2 ) due to its resource-rich locations, favorable policies, and early adoption. After Karnataka, Tamil Nadu has the second highest installed capac- ity of renewable accounting for nearly 45 percent. The recently elected ruling party assured power production and dis- tribution on a “wartime basis” in its elec- tion manifesto 3 . The Dravida Munnetra Kazhagam (DMK) government led by Chief Minister MK Stalin has also taken initial steps to follow 4 up on its promise to produce 20 GW of renewable energy by signing an agreement with Indian Re- newable Energy Development Agency (IREDA). Repowering old windmills is also on the state government’s agenda with a prom- ise to install new ones at the site where deteriorated ones exist now. Tamil Nadu has issued three policies 5 regarding re- newable energy since 2019 - Tamil Nadu Solar Policy, 2019; (ii) Tamil Nadu Electric Vehicle Policy, 2019; and (iii) Tamil Nadu Industrial Policy, 2021. An enabling envi- ronment for new technologies is one way of ensuring policy success. Let us start with the wind sector. The main hurdle in this sector is ageing and low-capacity turbines, which occupy the best wind sites. The wind turbines in- stalled in the early ‘90s were mostly of unit capacities less than 1 MW. Apart from replacing old windmills, Tamil Nadu could plan to repower some of them with new wind turbine models that use modern technology. Repowering could involve revamped infrastructure includ- ing higher efficiency wind turbine sizes, changes to the generators, blades, elec- trical equipment, and foundations. Along with suitable policy support and guide- lines for the safe disposal and recycling of decommissioned machines, the state could add much more wind power ca- pacity to the energy mix this way. Second, Tamil Nadu is blessed with great potential for offshore wind power produc- tion. Its coastline is over 1,000 kilometers long - about 15 per cent of India’s entire shoreline. According to scientists at the National Institute of Wind Energy (NIWE), this gives the state an estimated 35 GW of potential wind power capacity 6 . En- hanced LiDAR, 1 data accuracy, digitiza- tion, building interconnectors to strength- en the grid, exploring green hydrogen and energy storage solutions could help in accelerating the growth of offshore wind energy in the state. Third, Tamil Nadu’s installed solar capac- ity is just around 4.5 GW 7 , as of March 2021.This is only 2 percent of the esti- mated potential of 279 GW for the state. High potential in the state along with technological advancements enable it to allow exploring alternative options such as perovskite, polymer based, nano- crystal based, dye-sensitized (DSSC), concentrated, and transparent solar cell technologies. Considerable advances have also been made in technologies and solutions that help integrate solar PV into the grid. One example is bifacial solar cells which can harvest solar energy from both sides of the cells, augmenting power output by 10-30%. Most developed third genera- tion solar cell types are dye sensitized and concentrated solar cells. DSSC are based on dye molecules between electrodes. They are cheaper but they come with lower efficiency. On the other hand, perovskite solar cells (PSCs) have gained more traction due to their lower price, thinner design, low-temperature processing, and excellent light absorp- tion properties. PSCs perform well even under low and diffused light. Combined perovskite and Si-PV materials have shown a 28% efficiency 8 under laborato- ry conditions. Fourth, implementing energy storage systems is seen as a solution to not just manage the intermittency in high RE-rich states like TN but also to provide ancil- lary support. Lithium-ion batteries have witnessed tremendous interest over the Sandhya Sundararagavan (Lead - Energy Transitions), Energy Program , WRI India Kajol, Manager, Energy Program, WRI India