Street-heat: Controlling road temperature via low enthalpy geothermal energy

Abstract

In this paper, the authors present an idea to exploit low enthalpy geothermal energy in order to reduce street temperature fluctuations throughout the year and avoid ice formation during the winter season. The key aspect of the proposed system is that it is based on the exploitation of geothermal temperature gradients through materials with high thermal conductivity inserted into the ground, such as piles but without structural function, in order to create a preferable path for the geothermal heat to be spontaneously transferred to the street surface. The authors have carried out long-term dynamic simulations, by using the finite element discretization technique, to analyze the performance of the proposed anti-icing system. The obtained numerical results show that such a system could be effectively utilized for street heating, and proper design of both the system configuration and the thermal properties of the employed materials is important, in relation to the specific site and, as a consequence, to the exterior temperature and the subsoil temperature. A sensitivity analysis on the main geometrical characteristics of the system and thermal properties of the employed materials is presented, in order to assess the effects of these design parameters on the street heating performance.