part 1: overview of cogeneration and its status in asia - Fire

Summary of country study – Bangladesh 143
3.3 Pre-feasibility Studies at Selected Industrial and Commercial Sites
For the purpose of economic analysis, the total installed costs of the cogeneration plants
were assumed as follows: steam turbines: US$ 1,200/kWe; gas turbines: US$ 1,000/kWe;
and reciprocating engines: US$ 900/kWe. Some common financial data gathered or
assumed before conducting the pre-feasibility studies are summarized in Table 3.4.
Table 3.4 Financial data used for the pre-feasibility study
Parameters Unit Value
Exchange rate Taka/US$ 48.00
Tax rate Per cent/year 35.00
Discount rate Per cent/year 15.00
Cogeneration plant service life Year 15.00
Electricity purchase price Taka/kWh 3.60
Electricity buy-back rate Per cent of purchase price 80 per cent
Fuel price escalation rate Per cent/year 5.00
Electricity price escalation rate Per cent/year 6.00
Electricity stand-by rate Taka/kW.month 80.00
Fuel purchase price (natural gas) Taka/m 3
1.68
3.3.1 Recycled paper mill
This factory operates 24 hours a day and 350 days a year. Natural gas is used in boiler
furnace for steam generation. The electrical energy is required to drive the motors. The rate
of production is maintained up to the target level.
Analysis of the monthly electricity and steam consumption in 1997 led to the following:
• Total Electricity Consumption in 1997: 23,412 MWh
• Maximum Electricity Demand: 3,100 kW
• Minimum Electricity Demand: 2,750 kW
• Total Steam Consumption in 1997: 69,386 tons
• Maximum Steam Demand: 9.65 ton/hr
• Minimum Steam Demand: 7.15 ton/hr
The average power-to-heat ratios were found to be 0.52 in 1997. Typical cogeneration
system for this site would be based on steam turbine. However, reciprocating engine, gas
turbine cogeneration systems were also considered as potential alternatives. Results of the
feasibility study are summarized in Table 3.5.
Obviously, the steam turbine option does not seem feasible: (i) with steam turbine thermal
match (STTM), less than 25 per cent of the power requirement is generated; (ii) with steam
turbine power match (STPM), too much excess heat is generated.
With the reciprocating engine thermal match (RETM) option, 200 per cent excess power is
generated. The project profitability will depend on the buy-back rate. This may not be a good
option as the purpose is not to earn from electricity sale. Reciprocating engine power match
(REPM) option seems feasible as almost all the power needed can be met though an
auxiliary boiler will be necessary to make up for the 30 per cent shortfall in the heat supply.