Historical Background of TNEB

Electricity generation in Tamil Nadu until about 1908 was confined to a few tiny plants in Tea Estates run on water power and to a small hydro electric station at Kattery near Coonoor. The Government Electricity department was created in 1927. The Pykara Hydro electric Power Station was constructed by Sir John G. Henry Howard , a British Engineer and the first Chief Electrical Engineer of the then Composite Madras State Electricity Department and commissioned in 1933 with an original installed capacity of 70 MW. The Tamil Nadu Electricity Board was constituted with effect from 1st July 1957 under the Electricity Supply Act 1948 and came to be known as “The Madras State Electricity Board” with Padma Shri V.P. Appadurai appointed as Chief Engineer (Electricity).

The first thermal power plant was commissioned during 1971 at Ennore, Chennai with its first unit of 60 MW capacity. Naphtha based gas station of 10 MW capacity was commissioned at Narimanam during 1991-92.TNEB simultaneously ventured into wind generation and 120 units with a total capacity of 19.355 MW was commissioned in the period 1986-93. In 1992, the power sector was thrown open for private participation and the first independent power project was established by GMR Vasavi at Basin Bridge, Chennai.

About Us

Tamil Nadu Electricity Board (TNEB) was formed on July 1, 1957 under section 54 of the Electricity (Supply) Act 1948 in the State of Tamil Nadu as a vertically integrated utility responsible for power generation, transmission and distribution. The electricity network has since been extended to all villages and towns throughout the State. As per the provisions under the section 131 of the Electricity Act,2003 TNEB was restructured on 1.11.2010 into TNEB Limited; Tamil Nadu Generation and Distribution Corporation Limited (TANGEDCO); and Tamil Nadu Transmission Corporation Limited (TANTRANSCO).

Restructuring of TNEB

In the G.O Ms No 114 dated 08.10.2008, Government of Tamil Nadu has accorded approval in-principle for the re-organisation of TNEB by the establishment of a holding company, by the name TNEB Ltd and two subsidiary companies, namely Tamil Nadu Transmission Corporation Ltd (TANTRANSCO) and Tamil Nadu Generation and Distribution Corporation Ltd (TANGEDCO) with the stipulation that the aforementioned companies shall be fully owned by Government. More...

DATA CARD (2022-2023)


The installed capacity of conventional energy sources of Tamil Nadu Generation and Distribution Corporation Limited is 18,732.78 MW as on 31.05.17 which includes TANGEDCO’s Hydro (2307.90 MW), Thermal (4320 MW), Gas Stations (516.08 MW), share from Central Generating Stations (CGS) (6037.50 MW), Private Power Projects (PPP) (5551.30 MW). The installed capacity of non-conventional energy sources (infirm power) as on 31.03.2017 is 10,479.61 MW which includes wind generation (7854.81 MW), Solar ( 1702.40 MW ) Biomass (230.00 MW) and Co-generation plants (692.40 MW) ..More...


The total number of consumers being served in the State as on 31.03.17 is 279.27 Lakhs. Rajiv Gandhi Grameen Vidyutikaran Yojana (RGGVY) with the goal of creating electricity infrastructure to all un-electrified villages / un-electrified hamlets provide access to electricity to all households. Implementation of RGGVY in 26 districts of Tamil Nadu had already been completed. Further, implementation of the RGGVY scheme in Nilgiris, Tirunelveli and Dharmapuri districts is under progress. RAPDRP schemes are also being implemented to provide quality and reliable power supply to the consumers and to bring down the aggregate Technical and Commercial Losses (AT&C) below 15%. 

The total number of consumers being served in the State as on 31.03.22 is 324.54 lakhs

An efficient distribution network is needed for effectively utilizing the energy that is generated. TANGEDCO has an efficient distribution network that has grown over the years.


First cascading hydro-electric scheme – Kundah in the Nilgiris

This cascading hydro electric scheme consists of 5 power houses . It was developed with Canadian aid and was put into operation stage by stage from 1957 to 1964

First Barrage type Power House

Four Barrage type Power Houses each 2 x 15 MW were developed and commissioned during the year 1987-1989 across Cauvery river between Mettur and Bhavani. The Power Houses are located in the river bed itself

Kadamparai Pumped Storage Hydro Electric station ( 4 x100 MW)

The Kadamparai Pumped Storage Hydro Electric station (4 x100 MW) in Coimbatore District was commissioned in the year 1986 and is the first of its kind in the country to operate both in generation and pumping mode since 1987. In this Power House the off peak energy is utilized to pump water to the upper reservoir and during peak hours the Power House is put in generation mode.

First Gas Insulated Substation

In 1998 the first 230 KV Gas Insulated switchgear substation in the country was commissioned at Mylapore, Chennai. This was supplied and erected by M/s Merlin Gerin , France

Commissioning of 230 KV Transmission line

In 1960 TNEB commissioned 173 km long Kundah – Salem 230 KV transmission which was the first 230 KV network in the country

SCADA project

SCADA (Supervisory Control and Data Acquisition System) of Chennai Distribution Control Centre is the first in the country and it remotely controls all distribution substations in Chennai City.

Prestressed Concrete poles

The technology of prestressed concrete was developed in the 1960s. TNEB was a pioneer in setting up a PSC pole yard at Samayanallur near Madurai in 1970.

Power line Carrier Communication (PLCC) in Grid Operation

TNEB is the pioneer in India in introducing PLCC system for its own communication requirements. PLCC system utilizes 66/110/230/400 KV transmission lines as the medium for communication. PLCC provides for limited channels for speech communication, low speed data communication (200 bps) and protection tripping. In 1960 PLCC sets and protection couplers of Brown Boveri Corporation , Switzerland make were put into service in 66 stations.

First state to achieve 100 % Village Electrification

Tamil Nadu is the first state in the country to achieve 100 % electrification of all villages as early as 1992

Power Engineers Hand Book

The Power Engineers Hand Book published by TNEB Engineers Association is well recognized among the practising Electrical Engineers of the country. The Hand Book has its origin in the year 1947. The sixth enlarged version was released in 2002.


Generation During 2022-2023


Million Units

Thermal Generation


Million Units

Hydro Generation


Million units

Gas Turbine Generation



Peak Demand met on 16.03.2023

Distribution : (As on 31.03.2023)





Lakh Kilometers

Length of LT lines



Per Capita Consumption



Distribution Transformers

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