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

Summary of country study – Bangladesh 149
What if the electricity price escalates faster?
Internal Rate of Return
(IRR)
49%
47%
45%
43%
41%
39%
37%
35%
REPM
GTPM
6% 7% 8% 9% 10% 11% 12% 13%
% of Increase Fuel Price Escalation Rate
From the sensitivity analysis of the potential cogeneration alternatives for the textile spinning
mill, the reciprocating engine power match option meeting power requirement of 2,350 kW is
found to be the most suitable cogeneration system. It represents an initial investment of 102
Million Taka and leads to an internal rate of return of 41.9 per cent.
3.3.4 Textile processing mill
This factory operates 24 hours a day, for 340 days a year. Natural gas is used in boiler to
generate steam that is required for the process. The production process is sensitive to any
fluctuations in the power supply or power failures.
Analysis of the monthly electricity and steam consumption data of 1997 led to the following:
• Total Electricity Consumption in 1997: 7,433 MWh
• Maximum Electricity Demand: 1,100 kW
• Minimum Electricity Demand: 875 kW
• Total Thermal Energy Consumption in 1997: 89.3 TJ
• Maximum Steam Demand: 5.66 ton/hr
Minimum Steam Demand: 3.40 ton/hr
The power-to-heat ratio of the site was estimated as 0.3 for 1997. Typical cogeneration
system for this site would be based on steam turbine. However, reciprocating engine and
gas turbine cogeneration systems were also considered as potential alternatives. Results of
the feasibility study are summarized in Table 3.8.
The steam turbine option is found to be not suitable: (i) with steam turbine thermal match
(STTM), less than 20 per cent of the power requirement is met; (ii) with steam turbine power
match (STPM), 90 per cent excess power and 170 per cent excess heat are generated.
With the reciprocating engine thermal match (RETM) option, 325 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 the heat
generated meets up to 80 per cent of the demand. An auxiliary boiler will be necessary to
make up for the remaining 20 per cent shortfall in the heat supply.