CHENNAI: The sale of electricity to industries connected through High Tension (HT) power lines in Tamil Nadu has fallen sharply over the last 10 years, with data from the Tamil Nadu Power Distribution Corporation Limited (TNPDCL) showing that it has come down by 5,460 million units (MUs) in this period.
According to official records, TNPDCL sold 29,100 MUs of electricity to HT industries in 2015-16. This came down to 23,640 MUs in 2024-25, which is a drop of over 18%.
Officials said the main reason for the decline is the growing number of industries shifting to captive power generation, especially from renewable energy sources.
The decline has come despite the number of HT consumers in Tamil Nadu increasing from 5.98 lakh in 2014 to about 8 lakh now. Officials said the downward trend in sale is expected to continue in the current financial year as well.
A senior TNPDCL official told TNIE that power sale to HT industries could fall by another 2,000 MUs this year. “This is due to several factors, including changes in industrial power demand and the way industries source their electricity,” the official said.
HT power connection is compulsory for consumers whose electricity demand exceeds 150 kilowatt (kW). Consumers below this level are usually given Low Tension (LT) power supply.
“Many new industries have come up in different sectors over the last 10 years. However, we could not reach them and supply power to many of them due to the open access system, which allows industries to buy power from sources other than the state utility,” the official added.
Another official highlighted the rapid growth in the renewable energy sector. “Tamil Nadu had only 108.50 MW of installed solar power capacity in 2014. This has increased sharply to 11,664.81 MW in 2025. Similarly, wind power capacity has gone up from 7,269.59 MW to 12,075.34 MW during the same period,” the official said.
He pointed out that a large part of this renewable energy capacity is used by captive power consumers. The official also admitted that it is no longer possible for the utility to supply electricity to all industries, as the number of captive power users has steadily increased over the years.
K Venkatachalam, chief advisor and CEO of the Renewable Energy Association, said that repeated tariff hikes over the years have put many industries, including Low Tension (LT) consumers, under financial pressure.
He told TNIE, “Because of the multi-year tariff increase system, many industries have been struggling for the past few years. Instead of buying power from the state-owned discom, industries are now opting to set up their own power plants.”
He pointed out that the discom had raised power tariffs by 25% in 2022, followed by 2.18% in 2023, 4.83% in 2024 and 3.16% in 2025. “These repeated hikes have pushed HT consumers towards captive power generation,” he added.