Vol. 5 Num 892 Thu. November 30, 2006  

Problematic power sector

Power crisis is nothing new in this country. It has been estimated that the chronic power outage in Bangladesh generally results in a loss in annual industrial output of about $ 1 billion (about Tk. 7000 crore). Recently, however, the country has witnessed its worst ever power crisis. In October, the power generation went down to about 3000 MW against a peak demand of about 5000 MW.

The fact that new power plants could not be built during the past years is bad enough, but the unscheduled and frequent shutdowns of the existing plants have made the situation utterly unbearable. At one time, about 20 power plants were shut down. The recent crisis in the power sector is the outcome of the accumulated effects of multidimensional factors whose origins include politics, corruption, poor management and inefficient technical practices. The present article deals with a few technical issues related to the power crisis of this country.

The total number of power plant units in Bangladesh is reported to be 64 at present. Out of them, 18 units are more than 30 years old, 25 units are between 15-30 years old, and the remaining 21 are less than 15 years old. Thus, a substantial number of power plant units in this country are old. As the age of a power plant increases, so does the risk of failure of its components. Therefore, increased efforts are necessary to keep them running without unscheduled interruptions. The issue of aging power plants is, however, not unique to this country. It is a reality now, both in developed and developing countries. Worldwide, a substantial fraction of power plants are currently operating beyond their original design life.

Since the replacement of an old power plant is becoming prohibitively costly, it is often desirable to extend its life beyond the original design life. Efforts are, therefore, being made worldwide to extend the lives of aging power plants, and there has been marked progress in recent years in plant life extension technology. For extending the life of an existing plant it is first necessary to predict its longevity, which involves the assessment of its remaining life. Life prediction allows the smooth operation of the plant by avoiding unscheduled shutdowns caused by the untimely failure of aging components.

Power plants comprise of machines like boilers, turbines etc which operate under rather extreme conditions in terms of temperature, pressure, stress, chemical environment etc. In the ultimate analysis, the materials used for fabricating the components of these machines have to survive such adverse conditions. Very often, the unscheduled shutdown of our power plants and the resulting outages are caused by the failure of materials of these components. The performance of materials largely depends upon, among others things, the conditions under which they are used.

Therefore, monitoring and control of the operating parameters of power plant machinery, so as to comply with the specified limits. are so vitally important. The conditions of components can deteriorate drastically when the operating parameters exceed the specified values due to improper operation/monitoring. For instance, for a certain grade of steel that is used at high temperature, an operating temperature exceeding the specified limit by even a couple of tens of degrees (say 25oC) can cause a ninety percent reduction in component life.

In order to run the existing power plants smoothly, without unscheduled outage, it is time that we employed life prediction and, eventually, life extension technologies. For life prediction, the materials of different components of the power plants have to be examined non-destructively as well as destructively in order to find out the extent of accumulated damage. Both, macroscopic and microscopic investigations are necessary for this purpose.

The Department of Materials and Metallurgical Engineering (DMME) at BUET has the expertise and the basic facilities to conduct such investigations. So far, DMME-BUET has carried out analysis of the causes of failure of various components of different power plants and fertilizer factories in the country. A comprehensive collaborative scheme between the power sector and research institutions like BUET can allow the life prediction of our power plants on a routine basis.

As our economy expands, we will need more and more power. We should, therefore, develop our capability to smoothly operate and manage an increasing number of power plants in the future. This necessitates the building up of a strong technology and human resource base in our country to maintain and service these plants. In this country, we have been operating power plants for decades. But little technology transfer, if any, has taken place so far in this sector. This has been highlighted once again by the recent unscheduled shutdown of a large number of power plants, simultaneously.

Transfer of technology is something that does not happen automatically. This is particularly true for power plant technology. Power plants are complex engineering systems whose smooth operation and maintenance require multidisciplinary knowledge including electrical, mechanical, materials and chemical engineering. For technology transfer to happen in the power sector, deliberate, dedicated and multidisciplinary efforts have to be put in, in the long run. Long-term collaboration between the power industry and relevant research institutions is necessary to develop an indigenous technology base in the power sector. We should also create an enabling atmosphere in the power sector where technical personnel can excel, and are free to apply their professional judgments without any pressure from any quarter.

Whichever party/coalition wins the forthcoming general election will face a gigantic challenge in the power sector. The political parties should, therefore, take this matter seriously, and duly emphasize this in their election manifestoes. The need for the establishment of an indigenous technology base should be explicitly recognized in our power sector policy. And this should be followed by coordinated actions to create such a technology base within a reasonable time frame.

Dr ASMA Haseeb is Professor, Department of Materials and Metallurgical Engineering, BUET.