  The bifacial gain of East-West vertical and South-facing optimally-tilted
bifacial farms are well established. One wonders if bifacial gain (and the
associated LCOE) may be further improved by tracking the sun. Tracking bifacial
PV has advantages of improved temperature sensitivity, enhanced diffuse and
albedo light collection, flattened energy-output, reduced soiling, etc.
Monofacial tracking already provides many of these advantages, therefore the
relative merits of bifacial tracking are not obvious. In this paper, we use a
detailed illumination and temperature-dependent bifacial solar farm model to
show that bifacial tracking PV delivers up to 45% energy gain when compared to
fixed-tilt bifacial PV near the equator, and ~10% bifacial energy gain over
tracking monofacial farm with an albedo of 0.5. An optimum pitch further
improves the gain of a tracking bifacial farm. Our results will broaden the
scope and understanding of bifacial technology by demonstrating global trends
in energy gain for worldwide deployment.
