Production of renewable energy on closed landfills to compensate for biogas emissions: A case study of the Valdina landfill (Messina, Italy)

The contribution of integrated municipal solid waste (MSW) management systems to greenhouse gasemissions is not negligible, even though it is moderate compared with other anthropogenic activities.The main emission from landfills that accept biodegradable MSW is methane that escapes from thebiogas collection system. Such emissions are partially compensated if the collected biogas is exploitedfor energy production. Further compensation measures would also increase the overall sustainability ofthe landfill site. This study analyses the possibility of exploiting closed landfills to produce energy basedon the case study of the Valdina landfill (Messina, Italy). Two possible scenarios are presented: theinstallation of a photovoltaic system and the cultivation of giant reed (Arundo donax L.) to be used forenergy production through combustion. The results of a preliminary experimental activity are presentedfor the second scenario. The findings demonstrate the possibility of using the leachate produced in thelandfill for irrigation purposes. For each scenario, the costs, potential energy production rate, avoidedemissions and issues related to the integration of energy production with the landfill aftercare areevaluated. The presented results suggest that the cultivation of giant reed is the best option, especiallyduring the early post-closure period, in terms of investment (18,000 € against 8,300,000 €), highproduction yield in the Mediterranean climate, simplicity of cultivation and integration with ordinarypost-closure landfill management, limited cost of the energy produced (0.1€ kWh-1 against 0.27€ kWh-1).On the other hand avoided emissions are higher for the photovoltaic plant (27804 tC 2 against 778 tC 2on an horizon of 20 years).