Fig. 4
From: Meeting the demand: geothermal heat supply rates for an urban quarter in Germany
Illustration of the three studied shallow geothermal systems: horizontal ground source heat pump (hGSHP), vertical ground source heat pump (vGSHP) systems and groundwater heat pump (GWHP) systems. The nine studied scenarios consider variable heat extraction rates q (depending on groundwater flow GW, aquifer thickness m, a restriction of the drilling depth (RDD, no RDD), different BHE lengths l, and a fixed borehole heat exchanger (BHE) spacing d = 10 m. The cross-section along the green profile line (Fig. 3) shows the variation in aquifer thicknesses within the study site (UA = Upper Aquifer and LA = Lower Aquifer), the ground level and the depth of the water table