Comparative assessment of energy recovery from landfill gas and incineration for municipal solid waste management in Chennai, India: a case study using the IPCC default method and first-order decay model

This case study attempts to assess the suitability of landfill gas-to-energy (LFGE) and waste-to-energy (WtE) through incineration systems to manage municipal solid waste (MSW) in Chennai, India. The estimation of methane emissions from two primary dumpsites of Chennai (Kodungaiyur and Perungudi) by adopting Intergovernmental Panel on Climate Change (IPCC) Default Method (DM) and First-Order Decay (FOD) was undertaken in order to set up baseline scenarios and assess forecasting uncertainties. The amount of estimated methane generation was used to estimate the energy recoverability of LFGE and was compared with the WtE through incineration. The emission offsets from GHG reduction pathways are then converted to the possible Certified Emission Reduction (CER) credits in terms of an environmental and economic incentive to implement WtE solutions. The DM projected a relatively stable, near-linear trend in methane emissions at Perungudi, whereas the FOD model projected a gradual increase in methane emissions over the long term, with higher emissions towards 2050. Correspondingly, the LFGE recoveries were 38,959.64 MWh yr −1 in 2026 and 44,957.76 MWh yr −1 in 2050 using FOD model, and 29,769.04–31,740.42 MWh yr −1 using the DM. Among all WtE techniques, the incineration technology offered the maximum energy generation potential from 98,783.25 MWh yr −1 in 2026 to 105,324.92 MWh yr −1 in 2050. Besides energy recovery, the LFGE technologies play an important role for significant GHG reduction through capturing the methane, and contribute the betterment of environmental benefits and carbon reduction capacity of landfill management. The comparative analysis results indicated that FOD provides the strongest and most policy-relevant estimates for the long-term strategy development. Those results emphasize the importance of model choice in methane landfill inventories and strengthen Sustainable Development Goals (SDGs) 7, 11, 12, and 13 by enhancing renewable energy utilization, developing sustainable city management of waste, and mitigating climate change.