This paper describes a study of the optimum utilization of a low-temperature geothermal field in one of the larger cities in China. The task of how to utilize a low temperature geothermal field is a practical one. In its most general form, the goal is to find a solution where as few wells as possible need to be used. The demand of power for space heating is unfortunately not uniform and there is a peak demand during the coldest days. To meet the demand, a tradeoff has to be considered to combine geothermal energy (low running costs) and conventional boilers (low investment cost) for the lowest overall energy cost. Not only must the project be evaluated on an economic basis, the environmental aspect also plays an an important role and should be given due consideration