Converting Oil-fired Power Plants to Coal
By Akhtar Ali
There is some merit in this proposition. Oil has become quite a risky fuel, as the recent oil price hike has amply demonstrated. While apparently , there is no substitute to oil in transportation sector , the recent trend of installing oil based power plants(IC Engines mainly) has been rather unfortunate.
It is almost certain that oil would be extinct in the next fifty years and as its extinction phase starts, as it already has; its price behavior is projected to be quite volatile. Future price hikes ala 2008 cannot be ruled out. These would occur more frequently in future. Recent reliance in oil has perhaps been for no other short term alternative. Earlier oil-fired power plants have been installed in 30 USD per barrel regime.
Even Earlier oil fired power plants have suffered from low capacity utilization, although these were quite capable of running as base load power plants. A classic example is of HUBCO , which capacity utilization has improved very recently due to the power crisis. Otherwise, oil being expensive, HUBCO came in a low merit order and thus the low capacity utilization, which is ironic indeed for capital scarce countries like ours.
For the reasons discussed , oil fired power stations have been converted to Coal in Europe and ASEAN region in the wake of oil crisis of 1973 , and the trend continues. Despite general environmental dislike and opposition to coal, for instance,
In the U.S already, coal based power is abundantly installed to the extent of 50 % of the total installed power generating capacity , providing cheap power ( 5 cents or lesser per unit) from cheap coal .Apparently ,the U.S. has no reason to increase the already high predominance of coal , while other resource options are there like gas and nuclear.
Coal , however, is not immune to unruly price behavior. Recently, its price also hiked in the international market in sympathy with oil, to three times its usual level. Therefore, while imported coal could be a short term option, the longer term option has no escape from utilizing our domestic Thar Coal (lignite).Optimally Lignite is better utilized at mine-moth power plants. However, Lignite can be transported to a few hundred kilometers quite economically, comparatively speaking, as is being done in (hard) coal scarce northern regions of
Transportation is an important and significant component of the total received cost of coal and can add as much as 50% to the at-mine cost. Interestingly for some coastal towns, imported coal and its transport can be cheaper than domestic coal. This is one of the major reasons in
For a variety of reasons, Thar coal cannot be adequately utilized with Thar based installations alone. By 2030, our famous Energy Security Plan (2005) envisages 25000 MW to come from Thar Coal; even more, if the unrealistic projections of gas are taken into account. All of this capacity cannot possibly be installed at one location, whatever be the dictates of transport optimality. There are many issues like security based dispersal, water, ecological limitations, demand location, manpower etc.
For the time being, it is imperative that the proposition of converting Oil-fired power stations to coal be given consideration. It is a long cycle issue, and may take some 3-5 years to materialize .Already, new power plants based on imported coal have been proposed for Balochistan coast, near Hub Power Plant, and regulatory approval obtained in this respect. However, keeping in view the eventual potential conversion to Thar Coal, it is suggested that coal power plants be based on Sindh coast. There was a proposal earlier, mooted earlier in 1988, to install imported coal power plant at Keti-Bandar under the auspices of ADB. Infact, whole of Sindh coast extending from Bin-Qasim to Keti-Bandar is quite opportune for such siting keeping in view the closeness to Thar Coal.
Technically speaking, there are no limitations to the proposal. This is possible in today’s technology. In steam turbine based power plants, Oil fired boilers are to be replaced with coal fired boilers, although not a cheap proposition, as 30 % of the power plant investment may be in the boilers itself. Capital cost component in the unit product cost, do not exceed 15-20 % , bulk of it being the fuel cost. In the long run, even Gas fired combined cycle plants could be converted to coal based IGCC, a technology that would be commercially available in next five years. But let us not just delay action today for options of tomorrow.