Spatial albedo mapping using an autonomous rover for site assessment of bifacial PV power plant.

Conventional assessment methods of albedo measurement, like satellite imagery and on-site single-point measurements, lack the precision to address surface textural variances that can lead to power mismatches in a string of bifacial photovoltaic modules (BF-PV). To overcome this, we propose an innovative solution — an autonomous rover equipped with back-to-back pyranometers on its arm to measure the upward (plane-of-array) and downward (albedo) irradiance of a given surface. Employing an efficient path-planning algorithm, the rover ensures comprehensive spatial albedo data collection, overcoming the limitations of existing methods. The paper details the verification of the proposed methodology, its efficacy, and its importance over traditional approaches. This system enables holistic spatial albedo mapping of large areas, capturing textural/topographical non-uniformity, which is crucial for BF-PV installations. Simulations are conducted at the MBR Solar Park in Dubai, UAE, using albedo values measured and collected by the rover. The simulations involved calculating power output for a string of 20 modules across three cases of spatial albedo variations (0.32–0.38, 0.329–0.330, and 0.12–0.36). In the worst-case scenario (case 3), a power mismatch of 18.7% across the module string and a 4.2 °C temperature mismatch are observed. Cases 1 and 2 showed 4.6% and 0.2% power mismatch losses, respectively. These results underscore the critical role of precise spatial albedo measurements in optimizing installation conditions, emphasizing the need for spatial mapping to enhance energy yield estimates. • Developed a new methodology for spatial albedo mapping using a rover. • Highlighted importance of non-uniform spatial albedo on bifacial PV. • A novel albedo-map of an area of 1 sq. km to visualize topographical variation. • Power mismatch of 18.7% for a string of 20 modules when albedo variation is within 0.12–0.36. • Precise estimate for bifacial PV plant installation. [ABSTRACT FROM AUTHOR]