A mega power project transforms India’s most remote and power-starved region against all challenges


Tripura is a state that has been locked out of its own riches for decades.

One of India’s tiniest states, it is bordered on its north, south and west by Bangladesh. Five mountain ranges cut north-south across the state, the narrow valleys offering scant land for development. Only one major highway connects it to the rest of India, via steep slopes, weak bridges and serpentine curves.

Enormous natural gas reserves lie beneath its hilly ground — but too poor and too remote to tap into them, the state has always suffered a power deficit. This in turn has further limited Tripura’s industrial and economic development, like in much of India’s remote North East.

The local demand for gas was too low to commercialize the reserves and the terrain made it too difficult to pipe the gas to the Indian mainland

In late 2014, however, IL&FS helped Tripura become a power-surplus state with the largest individual power plant in the North Eastern Region (NER). The hitherto power-starved state now began supplying electricity to its neighbouring states, catalyzing development that is expected to transform the entire region. How did this become possible?

A Mega Power Project is conceived

The Oil & Natural Gas Corporation (ONGC) had in the early 1990s identified substantial gas reserves in Tripura, but was incurring huge losses here. The lack of industrialization in the region meant that the local demand for the gas was too low to commercialise these reserves. With the logistical difficulties and attendant costs of the region’s terrain, no gas pipeline to the Indian mainland existed either.

In 2004, with the support of the Government of Tripura (GoT), ONGC and IL&FS conceptualised the development of a Mega Power Project in Palatana in Tripura’s Udaipur district to monetise the gas resources into which ONGC had invested large initial capital.

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Sponsored by IL&FS and the Govt of Tripura, OTPC would be ONGC's first power plant in India

A 1090 MW Combined Cycle Gas Turbine (CCGT) thermal power plant was planned close to the Tripura gas fields. By supplying gas upstream and transmitting power to the deficit areas of North Eastern States of India the project was slated to bring in investments of around Rs. 9,000 crore to the region.

In 2008, IL&FS Energy Development Company Ltd (IEDCL) along with ONGC and GoT sponsored the ONGC Tripura Power Company Ltd (OTPC) to realise this project. Two distinct project components were conceived — generation of power through the CCGT power plant using the natural gas, and the transmission of power to the demand centres.

Both entailed enormous challenges.

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Tripura's location and the region's terrain posed huge challenges to the generation of power as well as its transmission

An audacious transport operation

The first challenge was transporting the large machinery to the site to set up the power station. The site with the gas reserves was in South Tripura, inaccessible through Indian territory for the transport of over-dimensional cargo (ODC). A pioneering strategic understanding was reached with the Government of Bangladesh to transport the machines using the waterways and roadways of Bangladesh. The support of the people and government of Bangladesh helped make this unprecedented feat possible. 

Loaded onto a barge at Kolkata and docked at Ashuganj, the oversized machines were transported through Bangladesh to reach Palatana

Employing local labour, OTPC built 16 bridge-bypasses, and widened and strengthened roads in Bangladesh to move 90 ODC consignments over its waterways and road infrastructure. The consignments, including a 350-tonne Gas Turbine, were loaded onto a barge at Kolkata, docked at Ashuganj in Bangladesh, then moved by road and across rivers through Bangladeshi territory to the sites in Tripura.

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The 350-tonne gas turbine being transported over nearly 50 km of roads and waterways of Bangladesh

OTPC strengthened and widened roads in Indian territory too, including sections of the NH-44, facilitated by the Border Roads Organisation and the Indian Government, with funds from the Ministry of Road Transport and Highways. Nine new bridge-bypasses had to be built, and several stretches of hilly roads had to be straightened to increase their turning radius.

Power transmission across forests and mountains

Evacuation of the generated power over the mountainous terrain was the second huge challenge. Across hills and forests, a 660 km long line was required to evacuate power from the plant to the national grid in Bongaigaon, Assam.

To meet this challenge, OTPC incorporated a separate joint-venture company, the North East Transmission Company (NETC) to implement the line, with OTPC and the Power Grid each holding a quarter of the share and the balance shared between the northeastern states, who would benefit from the line.

A complex process of Forest Clearance was completed, as one third of the transmission line passes through reserve forests in Tripura, Meghalaya and Assam. The transmission line encounters very high wind zones as it traverses the hills, and as no approved tower designs existed for such wind zones, NETC designed 12 new sets of towers and secured approvals after performing destruction tests on the prototypes.

Finally, before the line reached its destination in Assam, it had to cross the mighty Brahmaputra. To cross the river’s 5 km span, two special towers 150 m high were built, with 75 m deep well foundations in the river bed.


Twelve new sets of towers were specially designed and tested for the high wind-zones

A daring dream realised

With a total of around Rs 15,000 crore, this is the single largest investment in north-east India. The project has been a dramatic turnaround for ONGC Tripura — an asset that was running at a yearly loss of Rs 2000 crore is now among ONGC’s most profitable.

The power project was dedicated to the nation by the President and the Prime Minister, and also supplies power to Bangladesh

Through substations at Silchar and Azara in Assam and Byrnihat in Meghalaya, NETC facilitated 400 kV connectivity to these states as well as Mizoram, Manipur and Nagaland.


The 727 MW power plant uses state-of-the-art GE, USA machines

The President and the Prime Minister dedicated the ONGC Tripura Power Plant to the nation, with Petroleum Minister Dr Veerappa Moily acknowledging, “This daring dream will not only make the region power surplus, but also has provided a platform for further improvement of the ties between the two neighboring nations.”

Meeting this commitment, the plant supplies 100 MW power to power-starved Bangladesh, otherwise dependent on ‘contract power plants’ using liquid hydrocarbon fuel. The project also has the scope to supply power to Myanmar as soon as the evacuation facilities are developed.

One of the world’s largest CDM projects

This is one of the largest projects in the world registered under the Clean Development Mechanism of the United Nations Framework Convention on Climate Change (UNFCCC). It will earn India over a million carbon credits by mitigating over 1.6 million tonnes of carbon dioxide emissions per year for the next ten years. The plant is the first in the North Eastern Region to use advanced class machines of the environmentally sound 9FA technology.


With OTPC, ONGC achieves the rare feat of 10 CDM projects registered by a single organisation

The NER, hitherto dependent on seasonal hydro-power and inefficient state-owned open-cycle gas plants, now receives 24/7 base load power from the Tripura Power Plant — the region hasn’t seen a single power-cut owing to shortage since the plant began operations. The energy security is significantly promoting employment opportunities and stimulating the economy of the NER states.

At Rs 3/kWh, this is the cheapest and one of the most efficient power plants in the country. It is the only gas plant operating at 75% availability, which will increase to over 90% with the gas ramp-up next year.


The transmission line crossing the Brahmaputra's 5 km span before meeting the National Grid in Assam