While adding more generation capacity is a long-term plan to overcome power shortage, a short-term method is to improve the usage of existing plants. In the Indian context, this has shown good results where significant inefficiencies in operation existed until utilities and planners realised the efficacy of this approach and made concerted efforts.
In power plant parlance, capacity utilisation is termed as the plant load factor (PLF). This is arrived at by calculating the actual power produced against the maximum possible, theoretically, by a plant.
PLF for thermal plants in India, on an aggregate basis, has gone up from 54% to 74% over the last 20 years - a remarkable improvement of more than 20 percentage points. The uptrend also coincides with the formulation of a comprehensive policy on renovation & modernisation (R&M) of ageing thermal plants.
Improving the PLF is also evident from the figure of power produced per mega watt of generation capacity, which has gone up from 3.76 million units at the time of independence to 4.75 now. While this includes hydel plants, which run at low PLF, the change is significant. Although there was a slight dip in PLF in 2005-06 over the previous year due to shortage of fuel etc, the overall trend has improved considerably. Among the regions, the southern region had the highest PLF of 65.6%, while the eastern and the N-E regions recorded very low PLFs of 38.5% and 26.8%., respectively.
While the overall trend is good, a look at the sectoral performance brings out the anomaly. While the private & central sectors had a PLF of 85.4% and 81.9% respectively, the state sector, which accounts for about 57% of thermal plants, had the worst performance of 67.3%. This brings down the overall PLF significantly. What is worse, there is a wide variation in the PLF achieved by various state utilities with Bihar state electricity achieving a PLF of only 4.4%.
Apart from supplying the much-needed, another important impact of a higher PLF is a change in the cost structure, with a reduction in fixed cost per unit of output. For instance, for NTPC, a generation company, fixed cost as a percent of total cost was 33% in FY00, which has come down to 20% in FY06. As per a quick calculation, an increase of PLF from 80% to 90% would lead to a saving of 44 paise per unit of power for a coal-based plant. However, this would not apply for older plants, where most of the fixed cost has already been recovered.
Factors affecting PLF are age and size of units, equipment deficiency and failure, apart from high ash and wide fluctuations in quality of coal in India. R&M and life extension programme (LEP) of existing power plants is
being undertaken on a significant scale to reap maximum benefits through minimum capital investment.
In the context of limited financial resources available, this has helped achieve the desired results. As per CEA data, additional power of 25 billion units per annum is being generated through these programmes undertaken between the 7th and 9th Five-Year Plans. The programme, which involved capacity of about 35,000 mw, was undertaken at an expenditure of Rs 4,500 crore. It may be noted that this amount of power generation would require a capacity of 4,000 mw to be run at 80% PLF and cost of installation would be nearly Rs 16,000 crore.
Apart from operating factors, integration of regional grids - which allow uninterrupted power flow - has also aided the process of PLF improvement. Before the interlinking of the eastern region to the west and more recently to the north, the frequency used to go beyond the acceptable limit of 50.5 Hz, leading to backing down of thermal plants. The eastern region operated at high frequency of 51 Hz for more than 15% of the time in 2002 and 2003 because of low demand, which has been reduced to less than 0.1% now.
Another factor that has come into play in recent years, determining the PLF, is inadequacy of fuel supply. While shortage of coal led to a fall in PLF of only 0.3-0.4% during FY06, for gas it was much higher at about 9%. Generation loss for this reason has been about 1,650 million units and 7,700 million units, respectively. With continuing shortage and high prices of gas, things may continue to remain difficult in the near future.
In power plant parlance, capacity utilisation is termed as the plant load factor (PLF). This is arrived at by calculating the actual power produced against the maximum possible, theoretically, by a plant.
PLF for thermal plants in India, on an aggregate basis, has gone up from 54% to 74% over the last 20 years - a remarkable improvement of more than 20 percentage points. The uptrend also coincides with the formulation of a comprehensive policy on renovation & modernisation (R&M) of ageing thermal plants.
Improving the PLF is also evident from the figure of power produced per mega watt of generation capacity, which has gone up from 3.76 million units at the time of independence to 4.75 now. While this includes hydel plants, which run at low PLF, the change is significant. Although there was a slight dip in PLF in 2005-06 over the previous year due to shortage of fuel etc, the overall trend has improved considerably. Among the regions, the southern region had the highest PLF of 65.6%, while the eastern and the N-E regions recorded very low PLFs of 38.5% and 26.8%., respectively.
While the overall trend is good, a look at the sectoral performance brings out the anomaly. While the private & central sectors had a PLF of 85.4% and 81.9% respectively, the state sector, which accounts for about 57% of thermal plants, had the worst performance of 67.3%. This brings down the overall PLF significantly. What is worse, there is a wide variation in the PLF achieved by various state utilities with Bihar state electricity achieving a PLF of only 4.4%.
Apart from supplying the much-needed, another important impact of a higher PLF is a change in the cost structure, with a reduction in fixed cost per unit of output. For instance, for NTPC, a generation company, fixed cost as a percent of total cost was 33% in FY00, which has come down to 20% in FY06. As per a quick calculation, an increase of PLF from 80% to 90% would lead to a saving of 44 paise per unit of power for a coal-based plant. However, this would not apply for older plants, where most of the fixed cost has already been recovered.
Factors affecting PLF are age and size of units, equipment deficiency and failure, apart from high ash and wide fluctuations in quality of coal in India. R&M and life extension programme (LEP) of existing power plants is
being undertaken on a significant scale to reap maximum benefits through minimum capital investment.
In the context of limited financial resources available, this has helped achieve the desired results. As per CEA data, additional power of 25 billion units per annum is being generated through these programmes undertaken between the 7th and 9th Five-Year Plans. The programme, which involved capacity of about 35,000 mw, was undertaken at an expenditure of Rs 4,500 crore. It may be noted that this amount of power generation would require a capacity of 4,000 mw to be run at 80% PLF and cost of installation would be nearly Rs 16,000 crore.
Apart from operating factors, integration of regional grids - which allow uninterrupted power flow - has also aided the process of PLF improvement. Before the interlinking of the eastern region to the west and more recently to the north, the frequency used to go beyond the acceptable limit of 50.5 Hz, leading to backing down of thermal plants. The eastern region operated at high frequency of 51 Hz for more than 15% of the time in 2002 and 2003 because of low demand, which has been reduced to less than 0.1% now.
Another factor that has come into play in recent years, determining the PLF, is inadequacy of fuel supply. While shortage of coal led to a fall in PLF of only 0.3-0.4% during FY06, for gas it was much higher at about 9%. Generation loss for this reason has been about 1,650 million units and 7,700 million units, respectively. With continuing shortage and high prices of gas, things may continue to remain difficult in the near future.
