A reliable transient heat transfer model is used to ascertain the effect of solar thermal energy storage on a
geothermal system. The proposed closed loop system is comprised of a double pipe heat exchanger, and
is supplied with solar thermal energy during the summer months. The numerical simulations are based
on cases that are common in northern climates (e.g. Canada). A conduction-advection based model is
used to simulate heat transfer in the ground and in the heat exchange pipes for both heat extraction and
heat injection scenarios. The constant power configuration is employed to accurately assess the effects of
injecting thermal energy into a geothermal resource. The mass flow rate through the heat exchanger and
the solar energy input are varied during summer cycles to investigate the influence on the uptake of
thermal energy into the geothermal resource. The effects of rate of heat extraction and injection on the
techno-economic performance of geothermal energy production have been investigated.