Municipal solid waste and production of substitute natural gas and electricity as energy alternatives

The potential energy that could be derived from municipal solid waste (MSW) in Chile was estimated using a proposed methodological approach based on a techno-economic assessment. The supply-cost curves were used to present and compare the aggregated data for the energy potential and the cost of energy generation. The electricity generation alternatives assessed were landfill gas-to-energy (LGTE) and direct waste-to-energy (WTE) as well as gas collection and upgrading to feed into the grid (LGU). These options were evaluated and subsequently compared using such criteria as the production cost, the technical and economic potential and the short-term challenges for the country. In the cost modelling, information regarding the capital investment and reference technologies was gathered from the literature. This modelling allows for an estimation of the cost associated with energy generation for the previously indicated options. The estimated technical potential were 1.1 TWh_e y^-1 and 2.2 TWh_e y^-1 for the two first options, whereas the technical potential of the upgraded gas for injection was estimated at 260 MM Nm³ y^-1. The representative cost of energy generation, which was estimated as 11.0 ct kWh_e^-1 and 10.6 ct kWh_e^-1 for landfill gas burning and waste-to-energy, respectively, and 9.5 MMBTU^-1 for upgraded landfill gas for injection, was strongly influenced by the scale of the energy conversion units. Additionally, the indirect effects on cost were affected by the population concentration and landfill construction planning.