This study finds that the production profile (temperature and longevity) of low enthalpy geothermal reservoirs depends significantly on the thermal conductivity of the confining beds, which recharge the reservoir by conduction. The thermal recharge furthermore is proportional to the production rate and increases dramatically in thin reservoirs, while impermeable reservoir sections have little effect on the production profile. For the Margretheholm geothermal plant, Copenhagen, Denmark, production temperatures are modelled to decrease by only 7 degrees C-14 degrees C after 300 years of production due to thermal recharge. The study emphasizes the huge potential of geothermal energy in the development of environmentally sustainable cities. (C) 2014 Elsevier Ltd. All rights reserved.