Power shortage in Tamil Nadu became visible in the year 2000 when the shortfall was more than 2000MW. No new thermal plants were coming up, hydro potential was saturated and wind power was still in its nascent stage. The much-expected Jayamkondam Lignite Power Project fell through and the state’s plan to install 20 short gestation naphtha fired gas power stations was aborted. It was left to the old thermal plants in Ennore, Tuticorin, Mettur and North Madras to provide power to the state besides the seasonal hydro plants.
Wind Energy started coming up in a big way; however issues like evacuation problems, grid stability and payment delays were slowing down the progress. Power agencies predicted a grim future, projecting an alarming increase in the gap between supply and demand in Tamil Nadu in subsequent years.
A major thrust given by the Central government for involving private parties to enter into power generation took shape at this time. Called Independent Power Producers (IPP), these companies were given coal linkages and encouraged to set up power plants with guaranteed power-off take. However not many showed interest to put up plants in Tamil Nadu due to bottlenecks in the transport of coal.
In that decade, the Central Government also rewrote the Electricity Act, providing open access to power and giving opportunities for states to buy power from outside including private operators.
Studies pointed to a grim power situation in the second decade of the millennium. While the state was trying hard to bring new investments, the worsening power situation kept investors away. Domestic consumers were the worst sufferers.
Aware of this adverse trend, Tamil Nadu Electricity Board began concentrating on setting up new thermal power projects, hydropower generation being saturated. Additional units in the existing thermal plant sites were considered. Inland coal transportation being a serious bottleneck, coastal areas were explored for setting up new projects. For the first time, TNEB sought joint ventures with Central public sector undertakings in the power segment. Soon Central government came up with the plan for setting up ultra mega power projects each of 4000MW capacity through private participation and allotted one project to Tamil Nadu. The Kudangulam Nuclear Power station with two units each of 1000MW capacity started taking shape in this period.
Tamil Nadu Generation and Distribution Corporation (TANGEDCO) entered into joint venture agreements with the National Thermal Power Corporation (NTPC) and Neyveli Lignite Corporation (NLC) for putting up power stations. It also entered into an agreement with Bharat Heavy Electricals Ltd (BHEL) for setting up two 600MW units in the North Chennai Thermal power station. Significantly, all the new plants were of much higher capacity (500MW and above) compared to the 210 MW units in the early years. Simultaneously TANGEDCO took steps to buy power from outside the state.
Even though there were delays in commissioning the new plants, the efforts slowly started bearing fruit. Two 500MW units at Vallur under TANGEDCO-NTPC joint venture were the first of the new units to be commissioned in November 2012 and August 2013. The stage III 600MW in Mettur came into operation in October 2013. Other new units that have been added to the grid subsequently are North Chennai Thermal Station Stage II -1200 MW (with BHEL), Vallur Power Station -third unit 500MW (Joint venture with NTPC), Joint venture plant with NLC at Tuticorin- 500MW. Thus 3800MW power has come into the grid in the last 2.5 years. The second 500MW plant of the NLC_TANGEDCO combine is slated to be commissioned during the end.
After all the hiccups, unit 1 of Kundankulam Nuclear Power Station started production this year and Tamil Nadu will get 562 MW as its share when full generation is achieved. Hopefully, the second unit will also go into operation year end.
The peak demand in the state is hovering over 13,500 MW this year. The available power should be able to cater to the demand comfortably for the next few years.
Wind and solar power
Dependence on renewable power generation, especially wind power has become significant. Tamil Nadu has about 7GW wind power installed capacity and is the leading state in the country in this area. Apart from seasonal variability, wind power generation is highly variable even on daily basis and from available data, it can be seen on a typical day the wind power generation ranges from 50MW to 3000MW.
Variability in wind power generation poses greater challenges to grid stability. During high wind season, transmission lines are congested and subsequently there are problems in voltage stability and power quality.
The Tamil Nadu government has drawn an ambitious plan of buying 2000MW of solar power in the next 5 years. This has attracted many entrepreneurs and business houses to set up solar power plants in the state. Adani Group has signed an agreement with Tamil Nadu Renewable Energy Development Agency to supply 648MW to the grid by 2016. Like wind power, studies and preparations are for handling such power.
Power transmission and distribution
When TANGEDCO signed agreements with outside sources a major concern was how this quantum of power will be transmitted to Tamil Nadu since most of the private parties involved are in north and eastern states. Southern Region was not part of the national transmission grid and bulk power transmission has been almost impossible all these years. Luckily, last year the Southern Power Grid was linked to the National Grid. The interconnection of the line offered a major relief to Tamil Nadu from frequency problems. It helps facilitate power purchase from other states and smooth bulk power transmission.
Within the state, TANTRANSCO has drawn plans to augment the power transmission system.
While most of the villages in Tamil Nadu have been electrified, creating electricity infrastructure to all non-electrified hamlets and isolated villages and providing access to electricity to all households is in progress. Restructutred Accelerated Power Development and Reforms Programme (R-APDRP) is also being implemented to provide quality and reliable power supply to the consumers.
With the addition of new thermal plants, the successful efforts in tying power purchase from outside and the anticipated surge in renewables, the power situation is bound to be comfortable in Tamil Nadu in the coming years. The key factor will be the quick implementation of the planned projects.