Conventional ground based geothermal heating system
principles can be applied to landfills to recover the waste heat.
Vertical closed loop well systems can be drilled into existing
landfilled waste, and horizontal closed loop systems can be
installed at the base of a landfill during cell construction or
within the waste during waste placement. The likelihood of
return fluid temperatures in excess of 35o
C is high, allowing
for direct heating applications without the equipment and
operating costs associated with use of a heat pump. Smaller
open loop systems using leachate pooled in collection sumps
are viable for use in small landfill structures such as pump
stations and scale/guard houses. Lastly, limited vertical closed
loop well systems could potentially play a role in controlling
or eliminating subsurface reaction hot zones in waste, when
deployed at the onset of this phenomenon.