**4. Discussion, Policy Implications and Future Directions**

The WCA report [4] confirms that advanced coal technologies have a slightly higher LCOE compared to subcritical coal due to the initial higher capital costs. In contrast, results obtained in our work suggest that HELE technologies are economically competitive against subcritical plants. Since the WCA study does not cover details of LCOE calculations, methodology, data, and assumptions, the LCOE results for coal technologies in our work are not directly comparable to the WCA's LCOE results for coal technologies. In our work, a sensitivity analysis was carried out to evaluate the impact of different coal prices for 1000 MW-capacity coal-fired plants with life spans of 20 and 25 years and relies on IEA-listed thermal efficiencies for both technologies under different potential scenarios from ERIA's study in [23]. Therefore, our work in this paper is also not comparable with the ERIA study in [23]. Both the WCA and ERIA studies do not include an economic feasibility study of A-USC for the Southeast Asia region. In contrast, in our work, A-USC emerges as the most economically attractive choice, followed by USC and SC for the region.

The ASEAN member states will continue to rely on coal use to meet the growing electricity demand in the foreseeable future due to the energy supply security, as well as the competitive LCOE from coal plants compared to the other power generation technologies. Our study suggests that HELE coal-fired power plants are economically competitive against subcritical plants. This competitiveness of HELE technologies is associated with levelized avoided costs associated with high efficiency (and thus fuel savings) and low emissions.

To meet the 2DS targets, policies and associated measures are needed to address both the long-term and short-term challenges linked with electricity generation from coal-fired plants. Following are the policy implications of our study:


The cost of solar and wind technologies is also expected to drop in the future. In situations with strict emission control for coal-fired electricity generating plants (with carbon pricing and strict emission standards in place), switching from coal to these renewables would thus be expected. Nevertheless, the intermittent nature and low load factors associated with wind and PV technologies will likely limit their effectiveness in the region. In our future work, we aim to extend our cost–benefit analysis study by including solar and wind sources of energy generation in the ASEAN region. Financing costs also account for a considerable share of LCOE and the competitiveness of technology [38]. In recent years, multilateral development banks have adopted more restrictive finance policies for coal electricity generating plants to reduce emissions [4]. Exploring the impact of variations

in financing costs on the feasibility of HELE plants in the Southeast Asia region would be another interesting research direction.
