Characteristics of medium deep borehole thermal energy storage
In this publication, we describe the properties of medium-depth borehole thermal energy storage (BTES) systems, in particular their performance dependency on various geological and design parameters. Understanding these relationships is essential for optimizing the efficiency of thermal energy storage systems and improving seasonal heat storage capacities.
Numerical simulations of different storage configurations are used to quantify how parameters such as the length and number of the borehole heat exchangers, and the distance between boreholes affect system performance. Our simulations demonstrate the complex relationships between these design parameters and their effects on storage efficiency and heat yield.
The results show that with appropriate system dimensioning and favorable geological conditions, medium-depth BTES systems can achieve high storage utilization rates of up to 83 % after a certain period of operation. Furthermore, the study underlines the importance of choosing the right radial distance between the borehole heat exchangers in order to optimize the mutual thermal influence of the boreholes and thus the storage efficiency.
We also discuss the influence of operating variables, such as the temperature of the heat transfer fluid entering the storage system, and how adjusting these parameters can lead to improved performance. We conclude that understanding the sensitivity of the different factors is crucial for the optimal design and implementation of BTES systems to ultimately support their integration with renewable energy sources.
Our research thus contributes to crucial insights into the operational dynamics of medium-depth BTES and provides a basis for future studies aimed at improving the efficiency and applicability of thermal energy storage technologies.
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