Abstract: In a composting system for outdoor operation for large-scale composting of municipal and other wastes, one or more large compost piles or windrows are supported on a pad, and covered with a removable cover. Fluid circulation pipes are embedded within the pad, to recover heat generated by aerobic decomposition of the organic matter and to transfer the recovered heat to a region of the pad underlying an edge region of the cover. The recovered heat warms the edge region, to thaw snow and ice which may have built up on the cover at the edge region, permitting the user to easily remove the cover without damage. A computerized controller operates the system, including circulation of fluid from selected central zones to selected edge zones, with real time data collection of temperature at critical locations and optional serial extraction and application of heat from and to multiple regions on the pad.