In its search for alternative fuels, Tamil Nadu is looking at Orimulsion and heavy residue.
A committee headed by MRL is looking at the economic viability and the environmental fall out of using orimulsion.
With a high sulphur content, the environmental impact of burning orimulsion is a key aspect of any power plant based on this fuel.
Any plant using Orimulsion, for instance, cannot be put up at Ennore or Manali, north of the city, as this region already cannot take any more emissions.
But any power plant based on Orimulsion also has to be near the coast, given the transportation costs and its hazardous nature.
Venezuela is the world's single largest source of orimulsion, which is basically 70 per cent bitumen and 30 per cent water. Globally, some 2,000 mw of power is generated from orimulsion.
Transporting orimulsion all the way from Venezuela is both expensive and hazardous.
Among other things, the MRL committee will look into the possibility of transporting orimulsion without the water content.
This would ensure safer transportation, possibly at a lower cost.
As this will be done for the first time in the world, we will have to await the results of the expert committee, government sources said.
Meanwhile, Madras Refineries proposed a 350 mw heavy residue-based power plant in north Madras. Tamil Nadu Electricity Board will for the first time take an equity stake in the power project.
The other stakeholder is likely to be Tamilnadu Industrial Development Corporation.
The Central Electricity Authority is also being appreached for an equity holding but a final decision is yet to be taken.
With these three partners together holding 50 per cent equity, the power plant can rope in private promoters by signing an MoU instead of going though the more time-consuming international competitive bidding route.
Using heavy residue, however, poses a few problems and the various aspects of using it as fuel for power generation are now under study by a special committee constituted for the purpose.
For instance, heavy residue is normally burnt along with diesel but this is considered a costly option, given the heavy deamd for diesel. Also, investment in equipment is considerably higher, although operating costs are much lower than in conventional plants.
Thus, investment costs per megawatt are slightly higher and are estimated to range between Rs 4.6 crore and Rs. 4.7 crore.
For conventional thermal plants, it is around Rs 4 crore per megawatt.
According to officials, the growing power shortage justified such plants as the higher initial outlay wouls be compensated for with lower operational costs.
