Adani Power's supercritical thermal unit to go on stream soon

Having waited for nearly five years, India is finally set to roll over to supercritical coal-based power generation mode this month.Though officially two companies, NTPC and Adani Power (APL), are in the final leg of commissioning the country's first supercritical units of 660 MW each at Sipat (Chhattishgarh) and Mundra (Gujarat) respectively; sources say that the China-made APL unit is likely to go on stream, albeit on trial mode, in the fourth week of December.

A 660 MW plant, for example, can meet nearly 60 per cent of the average (non-peak) demand of Kolkata in a winter month. While neither NTPC nor APL officials were available for comments in this regard, sources told Business Line that the commissioning of the NTPC Sipat supercritical unit had faced “minor” delay.The unit is now expected to start trial generation in January. NTPC is using Russian and Korean super critical technologies.Generally, a unit with more than 500 MW capacity is referred as supercritical. The technology has derived its name from use of supercritical pressure for generation of steam — which rotates the generator — by firing coal.

Higher pressure reduces the boiling temperature of water. In supercritical technology the water is directly converted into steam, requiring lesser coal and thereby emitting lesser quantities of carbon in the air and generating lesser quantities of ash.

Apart from high degree of carbon emission, ash is the other major environmental concerns related to coal-based power stations.According to a back-of-the-envelope calculation, Adani Power will save use of 500 tonnes of coal a day for the 660 MW unit as against two units of 330 MW.

APL emerging majorIn other words, per MW supercritical generation will require 11 tonnes of coal or less as against more than 12 tonnes required in a traditional method.The upcoming 660 MW unit will step up the total generation capacity of APL's Mundra plant from the existing 1,320 MW (4 X 330 MW) to 1980 MW.The company is commissioning four more 660 MW at Mundra — almost in the gap of one in a quarter — to take the total capacity at Mundra to 4,620 MW in 2011-12.

Moreover, the first unit (660 MW) at Tiroda in Maharashtra is expected to be commissioned in the first half of 2011. The plant will have a total capacity of 33 MW (5 X 660 MW). Site development is currently on at Dahej (2640 MW), Kawai (1,320 MW), Chindwara(1320 MW) are on. The company is awaiting environmental clearance for 3,300 MW project at Bhadreswar close to Mundra.

Positive impactMeanwhile, reports suggest that APL is agreement bound to supply the entire generation from the upcoming 660 MW unit to the Gujarat state distribution utility.However, sources suggest that a power surplus-situation in the State as emerged during the last few weeks may offer some immediate windfall gains to APL through merchant sales once the 660 MW is on stream.