Geothermal energy has recently been a popular sustainable alternative for heating and cooling buildings. Due to its low power usage, ground heat exchangers employing piles have been recommended as a practical way to reduce initial costs and provide favorable long-term financial returns. In recent years, there has been increased interest in using steel foundation piles as ground heat exchangers. Steel piles are expected to deliver a better thermal conductivity and heat capacity than other energy piles.The thermal interaction between various components of a steel energy pile and the surrounding soil is presented in this thesis. To better understand the outcomes of the numerical simulations, the analytical relationships between the various physical processes involved in the thermal behavior of a steel pile have been outlined.The next phase was conducting numerical studies on the thermal performance of experimental research and creating a reliable three-dimensional numerical model that could be used in similar situations. The numerical simulation shows good agreement with the findings of the Saga University experiment.A similar numerical model was created based on the specifications of a trial piling project in Norway. Through cyclic heat injection in one pile and temperature monitoring in another, the short-term thermal performance of those piles was evaluated. This research demonstrates that short-term (72-hour) heat injection in a steel pile only affects a small area surrounding the pile, and consequently, the temperature fluctuation in the other pile was less evident.