Increasing the transmission performance of a conventional 110 kV cable line by combining a hydronic concrete pavement system with photovoltaic floor tiles

By combining the photovoltaic (PV) effect, heat exchanger principle, heat storage capability and phenomena of heat generation in PV cells and power cables, it is possible to increase significantly the transmission performance (i.e. the ampacity) of any 110 kV underground cable line. This can be achieved by installing power cables in a trench which is completely filled with high thermal conductivity bedding and which is covered with a hydronic concrete pavement (HCP) and a layer of PV floor tiles. This HCP, a heat storage system and a circulating pump are the three main parts of a HCP system, which should be used as a cooler for the PV tiles and cables. In particular, the PV cells would generate waste heat and direct current electricity from sunlight (using the PV effect), the cable bedding would conduct waste heat well from the cables to the heat collecting pipes of the HCP system (by improved heat conduction), while the HCP system would collect and store waste heat from the PV cells and cables as well as some heat from the Sun (using the heat exchanger principle and heat storage capability). The main aims of this paper are to show that the proposed method is highly energy-efficient, cost-effective and applicable in practice. The proposed method is regarded as a novelty, while the electricity generation in the PV floor tiles and the storage of heat within the HCP system represent additional advantages of this method. An adequate experimental background, one reference FEM-based model and one necessary base case are provided. For specified environmental conditions, the proposed method is verified numerically by means of COMSOL Multiphysics. Finally, the results of a techno-economic analysis are presented and discussed.