THOOTHUKUDI: Power generation at the Thoothukudi Thermal Power Station (TTPS) was adversely affected following floods on December 17, 2023. The plant has managed to fully resume operations a month later. Meanwhile, Tangedco has pegged the loss towards power generation, material, and restoration to more than Rs 350 crore. The state’s power agency has blamed the VO Chidambaranar Port for the same, and alleged that the authorities disregard for Tangedco’s warnings against levelling works on the peripheral ash dyke triggered the breach and the flooding of TTPS.
The VOC Port Authority had leased out area to the TTPS and the first unit was set up in 1979. The TTPS has been maintaining large ash dykes spread over 500 acres, including a primary dyke on 300 acres and a peripheral dyke of 120 acres, to deposit the bottom ash generated in its plant. The slurry of water and the bottom ash is piped into the primary dyke situated a km away on the northern side of the TTPS, between Hare Island and the mainland.
The primary ash dyke has a 14 m-high bund and the peripheral dyke is bound by a seven-metre tall bund. In case of excess rains, the peripheral dyke contains the ashes leaking from the primary dyke, thereby acting as a buffer zone preventing any ashes from flowing into the TTPS premises, said a senior official seeking anonymity.
According to sources, the VOC Port had begun levelling the bunds of the peripheral dykes from April 2023, to lease the land to manufacturing industries, but did not take consent from the power plant authorities and ignored earlier warnings. “Since the peripheral dyke area was levelled, the torrential rain on December 17 and 18 flooded the ashes from the ash dykes into the TTPS premises, choking both cooling water channels (each nearly two km long with a depth of five to eight metres) for more than a km,” an official said. These channels feed seawater for all units.
A top official said that a high-level meeting of revenue, industries, renewable energy, finance, and Tangedco departments, and VOC port chairman was held on October 10, 2022, to discuss the port’s proposal to divert the peripheral dyke area for industrial purposes. “It was decided that the VOC Port shall hold back levelling activities until a final decision is taken by Tangedco, following expert consultation by the TTPS,” he added.
Another official in the know of the developments noted that there were 11 letter communications with VOC Port, including four written by Tangedco’s chief managing director himself urging the central entity to immediately stop levelling works. One of the communications, accessed by TNIE, warned the VOC Port against further levelling the peripheral ash dyke given its proximity to the TTPS units, and the intensifying northeast monsoon. “Any losses caused by the unauthorised works at peripheral dyke should be borne by the VOC Port authority,” the letter had mentioned.
The last communication sent to VOC Port, flagging the dangers of levelling the dykes without permission, was on December 13, four days before rains submerged the city. As a result, TTPS officials said, the daily generation of 25.2 million units of electricity across all five units was hampered. Over 52 heavy machinery were pressed into service for a month to clear the choking water channels.
This man-made disaster could have been averted, had the VOC Port authority heeded to Tangedco’s communications. “TTPS incurred a daily production loss of Rs 10 crore, which totals to Rs 170 crore, temporary measures cost more than Rs 50 crore, and an additional estimate of Rs 100 crore for restoration works. It totals to around Rs 350 crore,” said a top official.
Speaking to TNIE, a senior official from VOC Port authority said that they have been actively demanding the peripheral and primary dykes for establishing industries since 2019, and that the Tangedco had not reached a decision. In place of these dykes, the TTPS was “unofficially” directed to utilise the new dyke, a swamp between the Hare island and the Thoothukudi Bay. “The TTPS, however, did not do it despite constructing a strong bund around it nearly 20 years ago,” he said.
TTPS is one of the oldest coal-fired thermal power plants in Tamil Nadu, and has been modernised to operate at its full capacity. Given the energy demand, the central electricity authority had already permitted the operations of age-old thermal power plants till 2030.