1. Key Findings Utility & Environmental Implications Table 5b: Generation capacity mix at selected energy tax rates in year 2025 Issue 1 Energy Tax Power Generation Capacity Mix at year 2025 (MW) Energy tax rate ($/Mbtu)00.512510 Hydro1764017910 182971809018187 Coal21400178001660010300100006000 FO+DO725 Gas949011230107951123052903820 Import3000 RETs2041946492149400 Total capacity (MW)530005180949494534914723041857 Shares in Power Generation Capacity at year 2025 (%) Energy tax rate ($/Mbtu)00.512510 Hydro33.2834.5736.1934.2138.3043.45 Coal40.3834.3633.5419.2621.1714.33 FO+DO1.371.401.461.361.541.73 Gas17.9121.6821.8120.9911.209.13 Import5.665.796.065.616.357.17 RETs0.040.810.9417.2319.9022.46

2. Key Findings Utility & Environmental Implications Table 6b: Electricity generation mix at selected Energy tax rates during 2006-2025 Issue 1 Energy Tax Electricity Generation (GWh) Energy tax rate ($/Mbtu)00.512510 Hydro121888112249401221503.5121285912131501123073 Coal1052220905567823518665492542100165512 FO+DO26941 Gas748413797472766782776810316066220408 Import333450 332143 RETs1872180973288684492213814 Total generation341021933364363232886.5313423426739532109476 Shares in Electricity Generation (%) Energy tax rate ($/Mbtu)00.512510 Hydro35.7436.7137.7838.7045.3753.24 Coal30.8527.1425.4721.2320.277.85 FO+DO0.790.810.730.861.011.28 Gas21.9523.9023.7224.7811.8210.45 Import9.789.9910.3110.6412.4715.75 RETs0.050.541.022.708.0010.14

3. Key Findings Fig1b: Installed generation capacity by fuel types at selected energy tax rates in year 2025 Fig2b:Electricity generation by fuel types during 2006- 2025 at selected energy tax rates Issue 1 Energy Tax

4. Key Findings Fig3b: Total electricity generation by hydro during 2006- 2025 at selected energy tax rates Fig4b:Electricity generation by coal during 2006- 2025 at selected energy tax rates Issue 1 Energy Tax

5. Key Findings Fig5b: Total electricity generation by gas during 2006- 2025 at selected energy tax rates Fig6b: Change in consumption by fossil fuels during 2006- 2025 at selected energy tax rates Issue 1 Energy Tax

6. Key Findings Fig7b: Effects of energy tax on power generation technology mix in year 2025 Fig8b: Generation mix during the planning period at different carbon tax rates Issue 1 Energy Tax

7. Key Findings Fig9b: Reduction in total capacity addition due to energy tax Fig10b: Reduction in total generation due to energy tax Issue 1 Energy Tax Reduction in total generation capacity addition due to Energy tax (%) Tax ($/Mbtu) -10 10 20 30 40 50 1.02.05.010.0 0.5 Reductions in total Generation due to Energy Tax (%) 0 10 20 30 40 50 00.51.02.05.010.0 Tax ($/MBtu)

8. Key Findings Table 7b: Weighted average thermal generation efficiency during the planning horizon at selected energy tax rates, % Table 8b: Weighted average loss of load probability and cumulative expected energy not served during 2006-2025 at various energy tax rates Issue 1 Energy Tax Energy tax rate (US$/Mbtu) Weighted average LOLP (%) EENS GWh%#%# 00.003272588.70.07591 0.50.00322517.50.07545 10.002421947.60.06007 20.001831397.60.04459 50.0000010.20.00001 101E-070.090.00000 Energy tax rate (US$/Mbtu) Weighted average thermal generation efficiency (%) 037.23 0.538.14 136.69 239.33 536.12 1038.95

9. Key Findings Table 9b: CO2 and local emissions mitigation reduction at different energy tax rates during the whole planning period, % Fig10b: Cumulative CO2 & local emissions reduction (%) during the planning horizon at different selected energy tax rates Issue 1 Energy Tax Energy tax (US$/MBtu) Vietnam CO 2 SO 2 NO x 0.58.86.9510.49 1.015.310.6218.87 2.026.120.6431.03 5.047.723.8455.30 10.078.168.9077.11

10. Key Findings Fig11b: Cumulative SO2 emission emitted during the planning horizon at different selected energy tax rates Fig12b: Cumulative NOx emission emitted during the planning horizon at different selected energy tax rates Issue 1 Energy Tax

11. Key Findings Fig13b: CO2 emission intensity in term of per unit of electricity generation at different selected energy tax rates Fig14b: Cumulative CO2 emission reduction (%) during the planning horizon tax at various selected energy tax rates Issue 1 Energy Tax

12. Key Findings Table 10b: The share of supply side effect and demand side effect to the total CO2 mitigation during the planning horizon at selected energy tax rates, % Issue 1 Energy Tax Energy tax (US$/MBtu) Vietnam SSEDSE 0.547.2952.71 1.047.2752.73 2.062.4237.58 5.037.6862.32 10.034.7165.29 Note: SSE = CO 2 mitigation due to supply side effect DSE = CO 2 mitigation due to demand side effect

13. Key Findings Cost Implication Table 11b: Average incremental cost (AIC) during the planning horizon at selected energy tax rates(US¢/kWh) Issue 1 Energy Tax Energy tax (US$/MBtu) Vietnam 02.70 0.53.04 1.03.36 2.04.04 5.05.43 10.07.70 CountryAICTotal cost Vietnam 10.311.7 Table 12b: Percentage increment in Average Incremental Cost and Total Cost with energy tax compared to carbon tax for a 10% reduction in total CO2emissions