This paper presents a three-dimensional numerical investigation on the effect of thermoelectric geometry on hybrid photovoltaic-thermoelectric (PVTE) performance under varying weather conditions. Four thermoelectric (TE) geometries corresponding to four different cases are considered under transient conditions and different thermoelectric leg height are investigated. The effect of the thermoelectric geometry and leg height on the efficiency and power output of the PV-TE is studied for a duration of 24 hours under actual weather conditions (solar radiation, ambient temperature and wind speed). Results show that the symmetrical thermoelectric legs (case 1) are beneficial for hybrid PV-TE under transient conditions. Although asymmetrical thermoelectric legs (case 4) provide higher thermoelectric generator (TEG) power output compared to other TE geometries, it also increases the PV temperature the most, therefore the overall PV-TE performance using such geometry is reduced. Consequently, asymmetrical TEG (case 4) is recommended for TEG only system while symmetrical TEG (case 1) is recommended for hybrid PV-TE under transient conditions. In addition, shorter thermoelectric legs provide enhanced performance.
Keywords Photovoltaic-thermoelectric; Asymmetrical legs; Transient study; Finite element method