“…This implies usage of a single small solar cell, which may not be able to provide enough power for the WSN in such environments, especially under low illumination levels (Carvalho and Paulino, 2013;EnerChip TM Smart Solid State Batteries, Cymbet Corporation, 2014;Hamilton, 2012;Kasemann et al, 2013;Pandharipande and Li, 2013;Paradiso and Starner, 2005;Randall and Jacot, 2003;Shigeta et al, 2013;Vullers et al, 2010;Wang et al, 2010;Weddell et al, 2011;Weddell et al, 2012). Under such conditions, it is significant to increase the amount of the harvested energy as much as possible (Prijic et al, 2015).…”