The Optimization of Geothermal Heating Projects With Heat Pump For Peak-Shaving, Based On Economic Evaluations

In China, geothermal energy has become increasingly important in building a low-carbon energy system, especially in promoting clean district heating. To improve the economic effectiveness and to achieve optimal scheme designs, a whole process analysis of geothermal heating projects and associated economic evaluations are conducted in this study. An optimization method of geothermal heating projects using heat pump for peak-shaving is proposed under the constraint of the expected rate of return. Firstly, the correlations between the peak load energy and the number of production/re-injection wells and the area of plate-type heat exchanger needed are established. Then, a relation model of the peak-shaving ratio and the variable costs, including the construction investment and the operation cost is constructed. Finally, based on the model, rapid calculations of expected rate of return and levelized cost of energy index under different heat pump peaking ratios are achieved through the development of a computational program. Based on such economic evaluation, the method provides optimal scheme designs for geothermal heating projects, including the optimal numbers of production wells and re-injection wells, and the optimized heat pump peak-shaving ratio under different outdoor temperature during the heating period.