Our first day back at school after our weekend adventure to the Agrotourismo contained a long block of group presentations about the differences in policies between various American states and European Union mandates. The next day (Tuesday) started off with a bus ride 20km north to visit the Ecoserdiana land fill where they used to landfill the municipal solid waste from Cagliari but have since stopped accepting MSW and have been taking “special” waste instead. What we saw being dumped was predominately industrial waste and fly ash. They were in the process of adding more capacity to their larger landfill by building on top of an already capped portion of the landfill. We learned that they were in a bit of a transitional period where the landfill gas being produced is declining because there is no more organic matter being land filled any more. I found it interesting that they had to pipe the landfill gas 2.5 km to an offsite co-generator location where they could then tap into the local low voltage distribution network. They were able to generate 1.9MW of electricity from their combustion generator. Ecoserdiana had also recently installed a 1.5 MW solar array to further utilize the capacity of their grid connection. I was personally glad to see that they were generating energy from the methane produced in the landfill but it seems much more efficient to incinerate waste entirely and then landfill the inert ash produced by the process.  

A view of the landfill as they prepare the existing landfill to be the bottom of the new landfill.