  With the rapidly growing interest in bifacial photovoltaics (PV), a worldwide
map of their potential performance can help assess and accelerate the global
deployment of this emerging technology. However, the existing literature only
highlights optimized bifacial PV for a few geographic locations or develops
worldwide performance maps for very specific configurations, such as the
vertical installation. It is still difficult to translate these location- and
configuration-specific conclusions to a general optimized performance of this
technology. In this paper, we present a global study and optimization of
bifacial solar modules using a rigorous and comprehensive modeling framework.
Our results demonstrate that with a low albedo of 0.25, the bifacial gain of
ground-mounted bifacial modules is less than 10% worldwide. However, increasing
the albedo to 0.5 and elevating modules 1 m above the ground can boost the
bifacial gain to 30%. Moreover, we derive a set of empirical design rules,
which optimize bifacial solar modules across the world, that provide the
groundwork for rapid assessment of the location-specific performance. We find
that ground-mounted, vertical, east-west-facing bifacial modules will
outperform their south-north-facing, optimally tilted counterparts by up to 15%
below the latitude of 30 degrees, for an albedo of 0.5. The relative energy
output is the reverse of this in latitudes above 30 degrees. A detailed and
systematic comparison with experimental data from Asia, Europe, and North
America validates the model presented in this paper. An online simulation tool
(https://nanohub.org/tools/pub) based on the model developed in this paper is
also available for a user to predict and optimize bifacial modules in any
arbitrary location across the globe.
