Geothermal Pavements: An Experimental and Numerical Study on Thermal Performance

One of the greatest challenges society faces today is the provision of clean and renewable energy to both meet the over-growing energy demand and reduce our carbon footprint. Ground source heat pump (GSHP) systems can efficiently heat and cool buildings using shallow geothermal energy and can therefore contribute towards the above goals. Significant attention has been given to energy geo-structures in the last few years, that is, using subsurface structures to exchange heat with the ground. Thus, these geo-structures provide structural support and thermal energy. The majority of literature relating to energy geo-structures focuses on piles, but only limited research exists on geothermal pavements. This work developed a detailed 3D finite element (FE) model to explore the thermal performance of geothermal pavement systems. This 3D FE model has been successfully validated against a full-scale experimental test undertaken in Adelaide, South Australia. The validated model is then used to evaluate the long-term performance of geothermal pavement systems under both a traditional system configuration and as a hybrid system configuration. The performance of the geothermal pavement system is analysed under three thermal loading cases including balanced, heating dominated and, cooling dominated cases, showing the potential and identifying possible limitations for geothermal pavements.