Impact of field design and location on the techno-economic performance of fixed-tilt and single-axis tracked bifacial photovoltaic power plants

In the design phase of the photovoltaic field for a bifacial photovoltaic power plant (B-PV), the influence of installation parameters on both the energetic and economic performance must be considered, which makes determining the cost-optimal field design a challenge. Although some studies have dealt with this topic, many questions remain unanswered. Therefore, this work investigated the site-dependent impact of the installation parameters row spacing, module elevation, tilt angle and soil reflectivity of a fixed-tilt and a single-axis tracked B-PV with an east-west and north south-axis on the energy yield, the levelized cost of electricity (LCOE) and the bifacial gain. Based on the results, the magnitude of the influence of an installation parameter on the energy yield and LCOE could be quantified for all three system designs. However, three findings are particularly noteworthy: 1. in the case of the fixed-tilt design, the relative energy yield gain caused by a larger row spacing increases with increasing latitude; 2. depending on PV field's configuration, soil brightening measures can significantly increase the energy yield of all three system designs, practically independent of location, and at the same time reduce the LCOE; 3. the choice of a too high module elevation can lead to small yield losses. Finally, the simulation model used was validated with the Swiss BIFOROT test array. In summary, it can be said that the complex interactions of installation parameters must be thoroughly investigated in order to avoid energy yield losses and unnecessarily high LCOE.