WE DISTINGUISH THREE MAIN TYPES OF GEOTHERMAL HEAT EXCHANGERS
Geothermal well Closed loop conventional vertical
PCP permanent column geothermal well
Geothermal well Open loop
Permanent column wells (PCP) appeared in the United States at the end of the 1980s under the leadership of Carl Orio.
• A PCP is a well 75 to 500 m deep.
• Water is pumped to the base of the well and reinjected to its top (or vice versa).
• The residence time is long (30-45 min) and the thermal capacity of the well is high.
• At the tip, the well is bled, which encourages a supply of groundwater into the PCP.
• The thermal efficiency of a PCP is approximately three times that of a closed-loop well.
• Pumped water must be returned to the original aquifer, a regulatory requirement.