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

174 Part3: Summary of country studies – Bangladesh and Viet Nam
Presently, it does not operate full capacity due to the Asian financial crisis. Consequently,
energy consumption has become an increasing burden on the hotel management.
Cogeneration appears to be one of the good solutions to reduce the high-energy bills of the
hotel.
Analysis of the electricity consumption of the hotel shows that main electricity consumer is
the air conditioning system, consisting mainly of chillers. The electricity tariff applied is very
high as the hotel is classified in the commercial and service sector category. The hotel has
already installed stand-by generators to provide enough electricity to satisfy its present
requirement. The cost of power generation with the diesel generators is found to be even
higher than the purchased electricity. A small amount of steam is required mainly for cooking
and washing purposes.
A possible alternative at this site would be the use of vapour absorption chillers that can
operate with the steam generated by recovering heat from the exhaust gases of the diesel
engine. The total electricity demand will thus be reduced because of the cooling supplied by
the absorption chiller.
Analysis of data gathered from the electricity and fuel bills in 1997 shows the following:
• Total Annual Electricity Consumption: 12,882 MWh
• Maximum Electricity Demand: 1,564 kW
• Minimum Electricity Demand: 1,363 kW
• Total Annual Steam Consumption: 7,245 tons
• Maximum Steam Demand: 1.6 tons/hr
• Minimum Steam Demand: 1.16 tons/hr
The power-to-heat ratio of the hotel is found to be 2.3, which is not suitable for any
cogeneration configuration. However, this can be changed by incorporating the absorption
cooling option that increases the steam demand to 7.5 ton/hour. The steam turbine and
reciprocating engine options are taken into consideration in the pre-feasibility study, and the
results are presented in Table 4.9.
Table 4.9 Summary of pre-feasibility study of the hotel “F”
Cogeneration Alternatives ALT.1 ALT.2 ALT.3 ALT.4
Configuration S.T. R.E.
Fuel type H.F.O. D.O.
Fuel price (VND) 1,800/kg 3,580/litre
Electricity purchase price (VND/kWh) 1,500
Buy-back rate (as % of purchase price) 70
Electricity price escalation rate (%/yr.) 5
Number of actual working hours per year 8,760
Heat generating capacity (kg/h) 15,000 15,500 12,400 1,250
Power generating capacity (kW) 1,287 18,096 15,366 1,550
Electricity consumption (MWh/yr.) 12,882
Thermal energy requirement (TJ/yr.) 287
Excess (+)/Deficit (-) heat (TJ/yr.) 0 84 -5 -259
Excess (+)/Deficit (-) power (MWh/yr.) -2,171 0 114,199 17
IRR (%) 25.6 20.2 29.6 27.5
Total installation cost (million VND) 38,480 42,617 139,668 39,385