February 2010 Issue (files are in PDF format)
The natural heat replenishment process for ground source heat pump systems is too limited to make such systems viable for large scale use in cities. Injecting heat (as in AE systems) solves that problem and in doing so it fundamentally changes both the technology and the economics.
Heat storage for large buildings
The GSHP heat replenishment process is particularly inadequate for large buildings. Heat injection permits the boreholes to be close together and their output is greater and more stable.