A planetary boundaries-based assessment of waste-to-energy technologies for sustainable waste management in Thailand

The rapid increase in global electricity demand and municipal solid waste (MSW) generation presents significant environmental challenges. Waste-to-Energy (WtE) technologies provide a promising solution by converting MSW into electricity, reducing reliance on fossil fuels. In this study, an absolute environmental sustainability assessment (AESA) is performed by using a Planetary Boundaries-based Life Cycle Assessment (PB-LCA) approach for three WtE technologies: anaerobic digestion (WtE-AD), incineration (WtE-In), and a hybrid of incineration and anaerobic digestion (WtE-Hyb), for MSW management in Thailand. Allocation methods for estimating the share of safe operating spaces were based on equal per capita at the national level and final consumption expenditure at the power sector level, respectively. Results of the AESA indicate that WtE-Hyb is the best-performing option among those considered, exerting the least pressure on planetary boundaries. Climate change was the most transgressed impact category, with WtE-AD, WtE-In, and WtE-Hyb emitting 520 kg CO₂ eq, 391 kg CO₂ eq, and 280 kg CO₂ eq, respectively, per tonne of MSW processed for electricity production. These emissions exceeded the estimated allowable limits by 8700%, 8400%, and 3100% for the three WtE options, respectively. Despite transgressing six boundaries, WtE-Hyb had the lowest pressure in five of them, except for freshwater eutrophication, where it exerted the second-highest pressure. In contrast, WtE-In transgressed the most boundaries (a total of 10) and exerted the highest pressure across all categories. The policy recommendations based on PB-LCA-based AESA results suggest stricter emissions controls, financial incentives, and public engagement to achieve sustainable waste management in Thailand.