RENOVATION & MODERNISATION FOR THERMAL POWER STATIONS
- In order to bridge the gap between demand and supply, especially in the context of limited financial resources available, it has become imperative to look for other options which are not as capital intensive as new capacity addition and which could be implemented in a comparatively shorter time frame. In this regard, optimum utilisation of existing installed capacity in the country to maximise the generation through Renovation & Modernisation (R&M) of existing power plants is considered to be the most cost effective option.
- The importance of R&M was recognised by the Government of India way back in 1984 when PHASE-I R&M Programme for 34 thermal power stations in the country was launched by the Central Electricity Authority as a Centrally Sponsored Scheme.
- The Government of India has now accorded high priority to R&M and Life Extension (LE) of old existing power plants. The funds in the form of loan assistance at concessional interest rates are being provided by the Government through Power Finance Corporation (PFC) for R&M works
- Historical background of R&M of Thermal power stations
At the time of Independence, power generating capacity in the country was 1362 MW only. Many new units were installed after Independence. Up to 1980, the total installed capacity of thermal power stations was 14,250 MW which comprised many imported units of sizes from 30 MW to 120 MW. The average Plant Load Factor (PLF) of thermal power stations during 1976-77 was 56%. However, due to various reasons, the PLF gradually started deteriorating as seen from the table given below:
Year-wise PLF Year PLF 1976-77 55.9% 1977-78 51.4% 1978-79 48.3% 1979-80 44.7% 1980-81 4.6%
As a result, thermal generation fell short of the targets, leading to a power shortage of about 11%, as compared to the requirement at that time.
Roving teams of the Central Electricity Authority (CEA)
A number of efforts were made to improve the operation of the units. Task Forces/Roving Teams consisting of experts from CEA, BHEL and ILK were constituted, which went around various thermal stations with a view to identify the defects/reasons for poor performance and to prepare action plans to address the problems. Based on the reports of Roving Teams, many State Electricity Boards (SEBs) prepared schemes for attending to the problems identified and included them in their annual plans. However, lack of adequate funds with some of the States led to lower priority being given to such programmes though there was an urgent need to attend to the problems of the thermal stations.
Causes for poor performance
The reasons identified for poor performance of thermal stations included the following:
- Design deficiencies, manufacturing and generic defects.
- The Operation and Maintenance (O&M) deficiencies causing prolonged and repetitive forced outages.
- Inadequate and non timely availability of spare parts especially for imported equipment.
- Lack of resources with SEBs even for making payments to BHEL against supplies & services and for coal supplies to coal companies. Accordingly, they were not able to take up the Renovation & Modernisation programmes to the extent required.
- The quality of coal being supplied had deteriorated as compared to the deigned quality. Besides, the coal had high ash content and contained stones, boulders, shale and sand.
- There was excessive and inadequately trained manpower for the O&M of the plant.
Stabilisation of 200/210 MW Units
During the early 1970s, it was decided to install bigger units of size 200/210 MW and BHEL started the manufacture of these units. Many such units were installed during 1979-82. Though a large capacity of about 5,000 MW was installed, these units were giving a lot of problems since the beginning and the PLF of these units was as low as 40%. Concerned with this, Stabilisation Teams comprising engineers from CEA, BHEL, ILK and the concerned power utilities were formed. These Stabilisation Teams visited all the stations where 200/210 MW units were installed and identified the problem areas. There were many teething problems and failures due to inherent design defects. These defects were studied and analysed in detail. BHEL and other original equipment manufacturers carried out the required modifications. Most of the modifications were carried out free of cost by the manufacturers on all the existing units irrespective of occurrence of the failure. The modifications were also incorporated for future units. As a result, the performance of these units substantially improved and got stabilised. Because of that efforts, 200/210 MW units are now operating at a level comparable to the of the best in the world. At present, there are about 160 units of 200/210 MW comprising about 44% of the total thermal installed capacity in the country.
- Phase-I R&M programme (7th plan programme)
- The Roving Teams constituted by the CEA comprising engineers from CEA, SEBs/Power Utilities, BHEL, ILK and Keltron visited various thermal power stations in the year 1984-85 and assisted SEBs in identifying areas of attention and formulation of R&M Schemes.
- As most of the States were not in a position to arrange adequate funds for R&M works, the CEA formulated a proposal called PHASE-I R&M Programme as a Centrally Sponsored Scheme for R&M of thermal power stations in the country. Accordingly, the Government of India approved the scheme and sanctioned a Central Loan Assistance (CLA) of Rs.500 crores to provide financial assistance to the SEBs for implementing the core R&M works/activities which could result in direct benefits in terms of generation. The funds for other activities were to be arranged by the States from their own resources. The R&M works relating to environmental improvement in the power plants were also accorded high priority and about 47% of the total investment was made on environmental pollution control measures. The 34 nos. of thermal power stations in various States were covered under the PHASE-I R&M programme.
- The implementation of the entire programme was coordinated by the CEA. The CEA took upon itself the responsibility of disbursement of funds and ensured that the funds were not diverted for other purposes. The next installment of funds were released on receipt of utilisation certificates from SEBs and funds to BHEL were directly released by CEA. Till the formation of Power Finance Corporation (PFC) in April 1988, funds were managed by CEA. The Programme was successfully completed during the 7th Plan and much more benefits than anticipated were achieved
- As advised by CEA, a Task Force headed by an officer of the rank of Member (Technical) was constituted in each SEB/Utility and a representative from CEA was also its member. The Task Fore had the power to take decisions and finalise orders/contracts for R&M works. This helped a lot in expediting the decisions and timely implementation of the R&M works. SEBs were also advised to set up separate R&M Cell at each power station and at Headquarters to deal with R&M works
The main features of the programme: (i) Number of thermal power stations covered 34 (ii) Number of thermal units covered 163 (iii) Total capacity involved 13570 MW (iv) Average PLF of 163 units before R&M programme 46% (v) Anticipated PLF after completion 53% (vi) PLF achieved after completion 56% (vii) Anticipated additional generation after completion of R&M programme 7000 MU/annum (viii) Actual additional generation achieved after completion of R&M Programme 10000 MU/annum (ix) Year of completion 1990-91 (x) Total expenditure incurred Rs.1066 Crores a) Central Loan Assistance Rs.402 Crores b) State Plan resources Rs.664 Crores (xi) Expenditure incurred on environmental activities 47%
The details of units covered are given in Annexure-I.
- PHASE-II R&M PROGRAMME (8th Plan Programme)
Encouraged with the results of implementation of PHASE-I R&M programme, the PHASE-II R&M programme for 44 thermal power stations in the country was taken up in the year 1990-91 for completion during the 8th Plan period. The CEA prepared the guidelines for preparation of R&M Scheme by SEBs and the Roving Teams constituted for PHASE-II of the programme visited various thermal power stations and assisted SEBs in the formulation of R&M schemes. Power Finance Corporation (PFC) was assigned the responsibility to provide loan assistance to the SEBs for R&M works.
The salient features of the programme: (i) Number of thermal power stations covered 44 (ii) Number of thermal units covered 198 (iii) Total capacity involved 20870 MW (iv) Expenditure incurred Rs.862 Crores (v) Anticipated additional generation after completion 4000 MU/annum (vi) Total additional generation achieved 5000 MU /annum (vii) Capacity taken up for Life extension Work (Units 1,2,8&9) of Neyveli TPS) 300 MW
The details of units covered are given in Annexure-II.
- R&M programme during 9th plan
Encouraged with the results of R&M/Life Extension works carried out during 7th and 8th Plan, the 9th Plan R&M Programme was taken up in 127 units at 29 thermal power stations. Most of the R&M activities identified under 9th plan programme have been completed.
The economic deigned life of the thermal power units is considered to be 25 years. 25 nos. of thermal units which had already completed their designed life were planned for LE works based on Residual Life Assessment (RLA) studies during the 9th Plan. The LE works on all the units have now been completed.
The salient features of the programme: Sl.No. Particulars R&M LEP (i) Number of thermal power stations covered 29 7 (ii) Number of thermal units covered 127 25 (iii) Expenditure incurred Rs.850 Crores Rs.1560 Crores (iv) Total Capacity involved 17305 MW 1685 MW (v) Expected capacity after LEP - 1741 MW (vi) Average PLF of the units before R&M/LE programme 61.5% 46% (vii) PLF anticipated after completion 63% 75% (viii) Anticipated additional generation / annum 2350 MU 4600 MU (ix) Actual additional generation achieved 5100 MU 4600 MU (x) Units on which LE works completed - 25 Units
The details are given in Annexure-III & IV.
- R&M programme during 10th plan
The CEA has identified 106 thermal units in consultation with SEBs/State Generation Corporations for LE during the 10th Plan so as to extend their economical life by another 15-20 years and to recapture /up-rate their capacities by implementing comprehensive R&M schemes based on RLA studies. In addition, another 57 units of 14270 MW capacity which are comparatively new also need some R&M work to sustain/improve their performance.
The salient features of the programme:
Life Extension Programme (LEP) Sl.No. Particulars (i) Number of thermal power stations 32 (ii) Number of thermal units 106 (iii) Estimated Cost Rs.9200 Crores (iv) Total Capacity involved 10413 MW (v) Average PLF of the units before LE programme 49% (vi) Anticipated PLF after completion 75% (vii) Anticipated additional generation/ annum 23700 MU (vii) Capacity expected after completion of LE works 10747 MW
The details are given in Annexure-V.
Renovation & Modernisation (R&M) Sl.No. Particulars (i) Number of thermal power stations 13 (ii) Number of thermal units 57 (iii) Estimated Cost Rs.977 Crores (iv) Total Capacity involved 14270 MW
The details are given in Annexure-VI.
- R&M programme during 11th plan
During the 11th Plan, 53 units with a total capacity 7,318 MW are programmed to be taken up for LE. Another 76 units with a capacity of 18,965 MW would be taken up for R&M.
The salient features of the programme: Sl.No. Particulars R&M LEP (i) Number of thermal power stations 21 23 (ii) Number of thermal units 76 53 (iii) Estimated Cost Rs.4487 Crores Rs.12433 Crores (iv) Total capacity involved 18,965 MW 7,318 MW
The details are given in Annexure-VII & VIII.
- National perspective plan for R&M and life extension of thermal power stations (up to 2016-17)
- Implementation of R&M programme
R&M is not a substitute for regular Operation and Maintenance (O&M) of the plant. There is a need to improve the O&M practices and carry out regular O&M as per schedules to sustain the improvement obtained through R&M. It should be ensured by the SEBs/Power Utilities that adequate and timely O&M funds are made available to the power stations
Ministry of Power in January 2004 issued a comprehensive guidelines for undertaking R&M and LE works in respect of thermal power plants for timely implementation of the entire R&M/LE works identified for completion during 10th Plan period. A copy of the guidelines is given as Annexure-IX
- Annexure I - Phase-I R&M Programme (7th Plan)
- Annexure II - R&M Programme (Phase-II)
- Annexure III - R&M schemes of thermal units covered under 9th Plan
- Annexure IV - Status of LEP works completed during 9th Plan
- Annexure V - Thermal units identified for life extension during 10th Plan
- Annexure VI - Thermal units identified for R&M during 10th Plan
- Annexure VII - Thermal units expected to be taken up under R&M during 11th Plan
- Annexure VIII - Thermal units expected to be taken up for LEP during 11th Plan
- Annexure A - Guidelines for undertaking Renovation and Modernisation (R&M) and Life Extension (LE) works in respect of thermal power plants