Title: Vertical Bifacial Solar Farms: Physics, Design, and Global Optimization,
Abstract: There have been sustained interest in bifacial solar cell technology since
1980s, with prospects of 30-50% increase in the output power from a stand-alone
single panel. Moreover, a vertical bifacial panel reduces dust accumulation and
provides two output peaks during the day, with the second peak aligned to the
peak electricity demand. Recent commercialization and anticipated growth of
bifacial panel market have encouraged a closer scrutiny of the integrated
power-output and economic viability of bifacial solar farms, where mutual
shading will erode some of the anticipated energy gain associated with an
isolated, single panel. Towards that goal, in this paper we focus on
geography-specific optimizations of ground mounted vertical bifacial solar
farms for the entire world. For local irradiance, we combine the measured
meteorological data with the clear-sky model. In addition, we consider the
detailed effects of direct, diffuse, and albedo light. We assume the panel is
configured into sub-strings with bypass-diodes. Based on calculated light
collection and panel output, we analyze the optimum farm design for maximum
yearly output at any given location in the world. Our results predict that,
regardless of the geographical location, a vertical bifacial farm will yield
10-20% more energy than a traditional monofacial farm for a practical
row-spacing of 2m (1.2m high panels). With the prospect of additional 5-20%
energy gain from reduced soiling and tilt optimization, bifacial solar farm do
offer a viable technology option for large-scale solar energy generation.