ABSTRACT
Solar cell systems for wearable applications are likely to consist of an array of PV cells whose output is connected to a DC-DC converter, a charge controller, and an energy storage device like a battery. Regardless of the configuration, the output of a PV array is conditioned by a DC-DC converter to a level that is both stable and compatible with the energy storage device in the system. The charge controller further adjusts the current and voltage supplied by the DC-DC converter to perform such functions as ensuring a battery can fully charge without being damaged. Wearable solar cell systems are especially problematic for batteries because the power that these systems produce is inconsistent and vulnerable to frequent and broad swings in input light type and irradiance (intensity) that are a natural consequence of a wearable system. Supplemental energy storage devices such as supercapacitors can be used to stabilize the power output of a PV array and provide more consistent and controllable input conditions to the system battery for a more reliable and long-lasting system. This chapter looks specifically at the DC-DC converter, charge controller, and energy storage components of a complete solar cell system in the context of wearable implementations.
