Kirigami-inspired automatically self-inclining bifacial solar cell arrays to enhance energy yield under both sunny and cloudy conditions

The application of photovoltaics (PVs) is expanding in various locations ranging from industrial facilities to residential housing. The emphasized concept in the PVs field is shifting from “watt-per-cost” to “energy-yield-per-watt.” To attain a high energy yield, fixed modules are not well suited to capture both direct and omnidirectional light. To achieve a high energy yield under both light conditions, we propose a self-inclining bifacial solar cell array fabricated by integrating a photothermal actuator, which senses incident light by itself, and actuating solar cells that incline at the appropriate angle to maximize captured light. In the vertical illumination state, the specific power of the self-inclining bifacial two-cell array is 11% higher than a fixed-angle aligned array. In an outside environment with a large proportion of diffused light, the self-inclining bifacial two-cell array also shows higher performance. We expect this work to enable PVs to be applied without regard to weather conditions.