A thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering

Thesis (M.Eng.) - Asian Institute of Technology, 1994

In this thesis study costs of electricity supply are calculated for unified Vietnam power system. Wien Automatic System Planning Package (WASP-3) is used for expansion planning. Marginal capacity cost is computed using average incremental approach. Continues linear programming has been utilized to formulate and solve problem of production optimization, which is run later in XA software. The dual variables of the output of XA are the direct input for calculating marginal energy cost. The day has been divided into three periods, namely peak intermediate, base periods. Two seasons for all regions in the country have been considered in this thesis. Costs of T&D network expansion are taken directly from references and included in capacity costs. Finally, electricity supply costs are differentiated by seasons, voltage levels and time of use. The highest capacity cost (19.61 $/kW/month) incurs at the peak period of the day during dry season for low voltage level. Average capacity costs at generation, HV, MV LV are 6.35, 10.51, 12.21 , 15.51 $/kW/month respectively. The corresponding marginal energy costs are 2.61, 2.82, 3.08, 3.41 cent/kWh. Average price of electricity including both capacity and energy cost component is about 6.655 cent/kWh. TOD tariffs are structured for industrial consumers, commercial consumers at MV and HV levels. L V level tariffs do not include TOD charge. All tariffs are structured for two seasons separately. The new tariffs ensure financial robustness of electric sector. With cross subsidization from MV and HV industrial consumers, a group of low income residents can enjoy certain amount (920 GWh as a maximum for year 2000) of electricity with low price to meet their minimum need (60 kWh per household per month). With the implementation of new tariffs, power sector financial status is stable. The rate of return achieves target value from the year 2003 onward, self financing ratio depends on scenarios and may be as high as 36. 87%.