Techno-Economic Comprehensive Review of State-of-the-Art Geothermal and Solar Roadway Energy Systems

Road infrastructure is a vital constituent element in the transportation network; however, roadway surface ice and snow accumulation leads to huge traffic accidents in winter. Geothermal roadway energy systems (GRES) and solar roadway energy systems (SRES) can increase or decrease roadway surface temperature for the de-icing and removal of snow in winter, or mitigation of heat in summer. Technology performance and economic evaluation of the GRES and SRES are reviewed in this paper based on numerical and economic models, and experimental analyses. Three crucial aspects of the technology performance assessment, i.e., roadway surface temperature, energy consumption and key factors, are explored in different regions and countries. Economic evaluation approaches for net present values and payback periods of the GRES and SRES are investigated. The recommendations and potential future developments on the two technologies are deliberated; it is demonstrated that the GRES and SRES could increase roadway surface temperature by around 5 degrees C in winter and decrease it by about 6 degrees C in summer, with the payback periods of 4 to 8 years and 2.3 to 5 years, respectively.