Combining direct ground cooling with ground-source heat pumps and district heating: Borehole sizing and land area requirements

This article studies the potential combination of direct ground cooling (DGC) with district heating (DH) and ground source heat pumps (GSHP) to compare the required borehole depths and needed drilling areas. It also examines two different borehole sizing approaches to optimize investment costs and drilling areas. The results show that the required borehole depths in most cases are shorter for the DGC and DH combination than for the DGC and GSHP combination. It is also demonstrated that the optimal range of borehole outlet temperatures could be chosen based on the trade-off between borehole installation and terminal units’ costs.