Energy Recycling – Landfill Waste Heat Generation and Recovery

Abstract

It is well known in the solid waste industry that waste disposed in landfills generates heat. Until recently, efforts to recover the heat and use landfills as a heat source did not exist. Landfill heat is generated from degradation of various waste types as a result of chemical and biological processes. Waste temperatures in landfills can range from 20oC to over 90oC under certain conditions. The principles of geothermal heating systems can be applied to landfills to recover the heat for space heating and other purposes. Landfill based geothermal systems are more efficient than ground based systems because ambient temperatures in landfills are warmer than the ground by 10oC to 45oC. Case studies indicate the high level of efficiency and cost effectiveness of landfill based geothermal systems, with simple payback periods in the range of 4 to 7 years when compared to conventional space heating technology.