Generation

Welcome to Generation Division!

We are committed to:
• Supply maximum uninterrupted Electricity to our consumers
• Maximise capacity utilization & be cost effective
• Continual performance improvements through innovation
• Integrate Safe and Environmentally friendly practices in O&M

We have three power plants with a total generation capacity of 1225 MW. Out of these three power plants Budge Budge Generating Station ( 750 MW ) is the youngest one (1997). The other two power plants are Titagarh Generating Station (1982) and Southern Generating Station (1990). Apart from New Cossipore Generating Station all other plants are based on pulverised fuel fired boilers. We have a rich history …

Our Power Plants A Brief History

The first thermal generating station of 15 MW capacity was erected in Cossipore on the 20th July 1912. Two more 6 MW sets were added in 1912 and another 15 MW set was added in 1925. Further augmentation continued till 1932 when the installed capacity of Cossipore Generating Station totaled to 96 MW. In order to cater to the requirement of the southern part of the city, a new generating station, Southern Generating Station, was commissioned on 22nd December 1926 at Metiaburz. Initial capacity of this power house was 22.5 MW comprising of three turbo alternators of 7.5 MW capacity each.
Gradually the installed capacity was increased to 70 MW. Further in the next phase of development another generating station, The Mulajore Generating Station, was commissioned in the suburbs of Kolkata on the 15th January 1940 with two 30 MW sets. Subsequent addition of turbo alternators followed in 1943, 1950 and 1951 resulting in a final capacity of 150 MW. The post World War II saw a boom for industrialization and the resultant demand for electricity gave birth to a modern power station which was named “New Cossipore Generating Station” in the year 1949. The station comprised of two 30 MW sets and one 50 MW set. Another 50 MW set was added in 1963 increasing the installed capacity of the plant to 160 MW. In 1978 Old Cossipore Station was closed down due to aging. From early seventies the power shortage over shadowed the south of Bengal including the city of Kolkata. During this period, expansion programmes of CESC was restricted due to then prevailing government and regulations, which were relaxed in the early eighties. To cope up with the enormous demand the company decided to construct a 240 MW thermal power station at Titagarh. The plant has four 60 MW sets commissioned between 1983 and 1985. In the year 1986 it was decided to replace the old and retired Southern Generating Station with a new modern power plant comprising of two sets of 67.5 MW, the first of which was commissioned in 1990 and the second in 1991. In the year 1988 the company was taken over by the RPG Enterprises. In 1989, West Bengal State Electricity Board handed over it’s Kasba Gas Turbine Generating Station ( with 2 X 20 MW Gas Turbine sets) to CESC on lease for Operation and Maintenance which continued till 1997. The youngest and largest power station of the company, Budge Budge Generating Station, consisting oftwo 250 MW sets was commissioned in 1997 to 1999 respectively. Later in 2010 the third 250 MW unit of Budge Budge was commissioned and thus the total generating capacity of Budge Budge became 750 MW. Due to ageing ofthe older plants, New Cossipore Generating Station has been derated to 100 MW station and Mulajore Generating Station has closed down in December 2003.

Coal to Electricity (Basic Flow)

• Coal as the primary source of energy is supplied from coal fields to our power plants by railways and is unloaded by wagon tippler
• Unloaded coal is either stacked or is next conveyed to the crushers to crush the large coal chunks into small sizes. Stacked coal is reclaimed later as ‘Stock Use’
• The crushed coal is conveyed to the bunkers. From the bunkers, coal goes into pulverizers {Coal Mill where it’s ground into the fine consistency of talcum powder. This powdered coal is known as Pulverized fuel.
• The pulverized coal mixed with air is blown into the boiler, where it burns at very high temperatures. As coal is burned, gas and ash are produced. Some of the ash falls from the furnace into ash hoppers (Bottom Ash). Fine particles of ash are carried with the combustion gas (Flue Gas) through the furnace. This ash (Fly Ash) is removed in electrostatic precipitators (ESP) before the gas leaves the plant through the stack. Thus ESPs are used to reduce the pollutants going to atmosphere.
• The boiler consists of large number of tubes and thus forms a rectangular room made up of tube walls. Water being circulated through the boiler’s walls of steel tubing is heated to produce steam. There is a drum at the top of the boiler where separation of steam and water takes
place.
• High pressure steam received from the boiler strikes the blades of the turbine, causing the turbine to rotate. The rotating turbine turns the rotor of electrical generator which produces electric current.
• The steam then leaves the turbine after the work done and moves into condenser. In the condenser the steam gets converted into water and is again pumped into the boiler to be heated to steam again. This cycle goes on. ·
• Electric current from the generator leaves the plant to begin its journey throughout the transmission and distribution system.
• Transmission towers support high voltage lines which carry electricity over long distances.
• At substations, voltage is decreased and electricity is sent through distribution lines into our neighborhoods.

Major Performance Parameters

In the mechanism of our power generation process, the key focus areas are

• Availability & Reliability
• Efficiency
• Sustainability

The most important objective of our power generation process is to provide uninterrupted power to our consumers at a competitive price. Availability & Reliability of a power plant is related to the following two elementary performance indicators:
Plant Availability Factor (PAF)
PAF measures the % availability of a plant to generate its’ full capacity in a given period of time.

Plant Load Factor (PLF)

PLF measures the % capacity utilization of a plant.

Auxiliary Consumption

A Power Plants use a host of motors, crushers, pumps and fans, all of which consume power. This power is met from the Plant’s own generation and is known as auxiliary power.

Heat Rate

Heat Rate is the amount of fuel energy (Kcal) required by a power plant to produce one unit (kilowatt- hour) of electrical energy.

Our target is to attain higher PAF & higher PLF. PAF is related to outage of a unit (full or part). Outages can be planned or forced. Outages like statutory overhauling of boiler, condition based maintenance fall in the category of planned outages, while outages like boiler tube leak, turbine bearing failure leads to forced outages. Sometimes operational failures, inadequacy of equipment and system disturbances causes forced outages from unit tripping. Maintaining high PAF & PLF is also a regulatory requirement.

To serve power to our consumers at a competitive price, power plant operation is needed to run efficiently, to be viable in the power generation business. While high PAF and PLF ensures maximum generation without any interruption, the economic generation of such units depends upon the following factors :

Auxiliary Consumption

A Power Plants use a host of motors, crushers, pumps and fans, all of which consume power. This power is met from the Plant’s own generation and is known as auxiliary power.

Heat Rate

Heat Rate is the amount of fuel energy (Kcal) required by a power plant to produce one unit (kilowatt­ hour) of electrical energy.
Keeping all the above figures low leads to low cost of generation.

Efficiency Improvement

Improvement of Auxiliary means improvement in efficiency which reduces coal consumption and benefits cost effectiveness and environment
We have revisited and modified various processes
• Operational optimisation of various high auxiliary consuming equipments like Feed Pumps, CW Pumps, Ash Water Handling Pumps etc.
• Implementing various Innovative practices
• Implementing Energy Efficiency Projects
• Implementing Various Energy Saving Projects

Improvement of Heat Rate means improvement in efficiency which reduces coal consumption and benefits cost effectiveness and environment
We have found and corrected all major areas of losses
O2 and CO
• Unburnt in Ash
• Flue Temperature
• Attemparation
• Makeup % of water
• Fixed Pressure/Sliding Pressure operation of Turbine
• Vacuum

Achievements

• Budge Budge Generating Station (BBGS): World’s first power plant to earn CER from UNFCCC
• Budge Budge Generating Station (BBGS): World’s first power plant to achieve 100% recycling of effluent
• Southern Generating Station (SGS): World’s first power plant to install micro hydel in CW out fall
• New Cossipore Generating Station (NCGS): World’s first power plant to install Wet ESP