31.05.2007 Unit I of TTPS has suffered a major breakdown due to sudden load throw-off to 34 MW which resulted in severe damage of all the moving and guide blades of the LP turbines. BHEL has provided its observation on the LP turbine following the blade failure and has recommended appropriate maintenance and replacement operations to be conducted (Annexure 2). Unit I will therefore not be available during FY 2007-08 since major overhauling and operation and maintenance would be required to be undertaken. Therefore electricity generation would be available only from Unit II. The PLF and generation are therefore expected to drop for the plant in FY 2007-08 and the projections are given below in Table 8:

Table 8: Projected Generation Performance for FY’07

3.3 Auxiliary Consumption

The auxiliary consumption is specific to a particular power station and depends on its configuration, age and related technical parameters. Auxiliary power is required for different equipments like feed pumps, cooling water pumps, air fans, coal grinding mills, ash handling equipments, common auxiliaries etc. of the generating station. The Petitioner has taken many steps to keep the auxiliary consumption of its units at minimum level like testing and calibrating defective meters measuring auxiliary consumption and installing digital energy meter in the Petitioner’s colony substation. As a result the auxiliary consumption has gone down to 12.04% in 2006-07 from 14.23% in 2005-06 and an average of 15.88% in the period 2000-2006

Historically, the auxiliary consumption of the station had been high due to measuring of auxiliary consumption by defective meters and in addition the high auxiliary consumption included -

·    Colony consumption.

·    Other loads in the vicinity of the power station.

·    Transmission losses of 220/6.6 kV Transformers.

Only one generating unit is working at present

The following measures have been taken to reduce the auxiliary consumption -

·        Feeding station loads from the unit transformers (2x16 MVA) instead of station transformers (4x40 MVA).

·        Metering the colony consumption and other loads fed from the station.

·        Second generating unit coming to operation.

With the above measures it is estimated that the auxiliary consumption have come down to around 12.04% in 2006-07. The petitioner pleads the Honourable Commission to accept auxiliary consumption of 12% for the year 2007-08.

Table 9: Projected Auxiliary Consumption for FY’07

3.4 Heat Rate

The actual heat rate for the generating plant has been 2946 kCal/kWh and 2958 kCal/kWh for the years FY 2004-05 and FY 2005-06 respectively. However the Honourable Commission approved the normative 2500 kCal/kWh in its tariff orders for the two years. The all-India weighted average heat rate for plants as per the Central Electricity Authority’s (CEA) Review of Performance of Thermal Power Stations (2005-06) has been 2788 kCal/kWh and 2747 kCal/kWh for FY 2004-05 and FY 2005-06 respectively and that for the Eastern region the average has been 3148 kCal/kWh and 2887 kCal/kWh for FY 2004-05 and FY 2005-06 respectively. The Petitioner therefore requests the Honourable Commission to take cognizance of ground realities as also observed by the CEA.   

The actual heat rate observed in FY 2006-07 is 2821 kCal/kWh which is below the average for Eastern region coal based thermal power plants as observed by the CEA. The Petitioner therefore requests the Honourable Commission to consider the FY 2006-07 heat rate for the FY 2007-08.

Table 10: Projected Heat Rate for FY’07

3.5 Specific Coal Consumption

The Petitioner sources D grade coal from the collieries of Central Coal Fields Limited with calorific value of about 4300 kCal/kg.

Table 11: Specific Coal Consumption

The all-India average specific consumption of coal as per CEA’s Review of Performance of Thermal Power Stations (2005-06) the all India for 2005-06 was 0.7 kg/kWh and for Eastern region as a whole it was 0.72 kg/kWh. However, the Honourable Commission approved only a normative specific consumption of coal of 0.56 kg/kWh which is far off from the realistic specific coal consumption observed in the country and the eastern region. Since the unit outages have reduced over the past two years and the station is achieving a higher PLF than in the past the specific consumption of coal has reduced to 0.656 kg/kWh in 2006-07 from 0.688 in 2005-06. This is still much below the national and eastern region average observed by the CEA. In 2007-08 specific coal consumption is expected to be remain at 0.656 kCal/kWh. The Petitioner requests the Honourable Commission to consider the actual specific coal consumption  observed by the Petitioner in its generation plant.

Table 12: Projected Specific Coal Consumption for FY’07

3.6 Secondary Fuel Consumption

Due to the large number of outages experienced by the station due to transmission line trippings etc., the Petitioner has not been able to achieve the norm of 2 ml/kWh fixed by the Honourable Commission for specific oil consumption. The Petitioner had therefore proposed specific oil consumption of 4ml/kWh during FY 2005-06 against which Honourable Commission approved 3.78 ml/kWh finding merit in the Petitioner’s request. The following Table 7 below provides the trend in specific oil consumption over the last 7 years.

Table 13: Specific Oil Consumption

The Honourable Commission is well aware of the fact that the normative specific consumption is not possible to be achieved in a short time span given the ground realities the Petitioner faces, on the basis of which the Honourable Commission approved specific oil consumption of 3.78 ml/kWh for FY 2005-06. The delivered cost of oil at the thermal station by the oil companies has also increased to Rs. 27835/kl in FY 2006-07 from Rs.20555/kl in 2004-05 at a compounded annual growth rate (CAGR) of 16.4%. The Petitioner has however endeavored to reduce the specific oil consumption and has brought it down to 2.31 ml/kWh in FY 2006-07. The Petitioner shall endeavor to achieve stability in retaining it at that level and therefore requests the Honourable Commission to approve specific oil consumption at 2.31 ml/kWh for the FY 2007-08

Table 14: Projected Specific Oil Consumption for FY’07

3.7 Summary

Based on last year’s performance the Petitioner has projected the following for the FY 2007-08:

Table 15: Projected Generation Parameters for FY’07