Supercapacitor-based embedded hybrid solar/wind harvesting system architectures

Off-grid medium-power (1–10 W) systems require either battery-or supercapacitor-based ambient energy harvesting for sustaining their operation. Supercapacitor-based harvesters are advantageous in autonomous field systems due to their extended lifetime, easy power management, and low maintenance requirement; however, they can reach only up to 10% of the energy density of rechargeable batteries. To overcome this energy density challenge, hybrid power sources, such as solar or wind, can be advantageously utilized in harvesting systems. The complementary power supply characteristics of solar and wind can substantially reduce the required supercapacitor buffer size compared with solar-only or wind-only systems. In the literature, no supercapacitor-based hybrid harvesting system design exists for 1–10 W range. In this paper, we develop and experimentally validate three different categories of supercapacitor-based harvesting systems that are capable of simultaneously harvesting solar/wind (hybrid) power sources.