Enhanced charge circuitry for indoor photovoltaic energy harvesting with fast activation and high efficiency

Abstract

AbstractUsing batteries in low‐power Internet of Things (IoT) devices poses a risk of environmental pollution. Energy harvesting (EH) systems are needed to capture ambient energy and charge supercapacitors to address this issue. Indoor photovoltaic (PV) panels are a promising power source, but their weak ambient energy makes it challenging to activate IoT end nodes quickly. Here, an EH system enhanced charge circuitry with fast activation is proposed that reduces IoT end nodes activation time to less than 2 s, compared to the traditional 19.8 h, if an indoor PV panel supplying 28 µA to charge a 1 F capacity supercapacitor from 0 to 2 V. This system also offers high‐efficiency charging, enabling supercapacitors to replace batteries, particularly when charging from 0 to 1.2 V, with a charge time improvement ratio of 64%. These breakthroughs address long‐standing challenges in IoT power systems and reduce environmental pollution.