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 ($/Mbtu) Hydro Coal FO+DO725 Gas Import3000 RETs Total capacity (MW) Shares in Power Generation Capacity at year 2025 (%) Energy tax rate ($/Mbtu) Hydro Coal FO+DO Gas Import RETs

Key Findings Utility & Environmental Implications Table 6b: Electricity generation mix at selected Energy tax rates during Issue 1 Energy Tax Electricity Generation (GWh) Energy tax rate ($/Mbtu) Hydro Coal FO+DO26941 Gas Import RETs Total generation Shares in Electricity Generation (%) Energy tax rate ($/Mbtu) Hydro Coal FO+DO Gas Import RETs

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

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

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

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

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 ($/Mbtu) Reductions in total Generation due to Energy Tax (%) Tax ($/MBtu)

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 at various energy tax rates Issue 1 Energy Tax Energy tax rate (US$/Mbtu) Weighted average LOLP (%) EENS GWh%#%# E Energy tax rate (US$/Mbtu) Weighted average thermal generation efficiency (%)

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

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

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

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 Note: SSE = CO 2 mitigation due to supply side effect DSE = CO 2 mitigation due to demand side effect

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 CountryAICTotal cost Vietnam 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