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

Summary of country study – Viet Nam
Total installation cost (million VND) 20,561 121,748 67,409 84,443
Pay back period (year) 10 10 7 7
Note: TM: Thermal Match; PM: Power Match
The first alternative, with boiler and steam turbine configuration, has the lowest investment
cost among the four considered options and an acceptable IRR.
The alternative 2 would lead to generation of more than 150 per cent excess electricity. Its
IRR is almost the same as that of alternative 1 but it requires the highest investment among
the four considered options. The alternative 3 seems to be the most attractive with the
highest IRR but its investment cost is three times higher than that of alternative 1.
The alternative 4 could also be attractive but natural gas is presently not available at the site.
4.3.3 Textile mill “C”
Built in the 1960s, the Textile Company “C” is one of the biggest companies in the North of
Vietnam. In 1997, 4,400 tons of cotton yarns, 16 million metres of raw fabric and 18 million
metres of finished fabrics were produced in the mill.
Currently energy represents 16 per cent of production cost. Electricity is used for machines,
lighting and air conditioning. Steam for process is generated in coal fired boilers. The
application of the cogeneration technique for this company is suitable, since the company
wants to reduce the annual electricity and energy costs.
Results of the analysis of data gathered from the electricity and fuel bills are summarized
below:
• Total Annual Electricity Consumption: 31,000 MWh
• Maximum Electricity Demand: 5 MW
• Minimum Electricity Demand: 4.3 MW
• Total Annual Coal Consumption: about 315,000 tons
• Maximum Steam Demand: 20 tons/hr
• Minimum Steam Demand: 12 ton/hr
Table 4.5 Summary of pre-feasibility study of the textile mill “C”
Cogeneration Alternatives Alt.1 Alt.2 Alt.3 Alt. 4
Configuration S.T. R.E. G.T.
Chiller (110 kW x 6) Electric
Fuel type Coal H.F.O. N.G.
Fuel price (VND) 350/kg 1,800/kg 3,710/GJ
Electricity purchase price (VND/kWh) 800
Buy-back Rate (as % of purchase price) 70
Electricity price escalation rate (%/year) 5
Number of actual working hours per year 7344
Heat generating capacity (kg/h) 18,594 54,985 3,986 8,891
Power generating capacity (kW) 1,503 4,443 5,000 4,443
Electricity consumption (MWh/year) 31,000
Thermal energy requirement (TJ/year) 359
Excess(+)/Deficit(-) heat (TJ/year) 0 596 -282 -187
Excess(+)/Deficit(-) power (MWh/year) -20,517 0 3,884 0
169