Optimization of Medium-Deep Borehole Thermal Energy Storage Systems
This paper presents an approach to optimize the design of medium depth borehole thermal energy storage systems (MD-BTES). For this purpose, a MATLAB-based tool for numerical simulation of such systems is used to train a proxy model based on the Polynomial Chaos Expansion (PCE) method. This enables a high-level approximation and accelerated calculations as well as the application of mathematical optimization methods. The aim of the optimization is to increase the storage efficiency and minimize the construction costs of the system. By defining a suitable operating scenario and parameter space, we enable an evaluation of the system performance under consideration of geological uncertainties. Our results show that even small changes in parameters can have a significant impact on storage efficiency, leading us to recommend strategies that consider wider parameter bounds during training simulations to improve optimization accuracy.