Identification some of the temperature related factors affecting hybrid PV- MTEG systems efficiency by experimental methods

Due to widespread implementation of the renewable energy development programs the solar energy use is growing constantly across the world. However, the photovoltaic solar cells used for primary solar energy conversion into electrical energy exhibited significant drawbacks. The fundamental downside is unstable and low efficiency with the energy conversion process being negatively affected by a range of factors. To neutralize or minimize the impact of those factors causing energy losses, researchers have come out with varied ideas. One of promising solutions offered by researchers is hybrid photovoltaic-thermoelectric generator system combining both photovoltaic cells and thermoelectric generators advantages. The proposed hybrid system model was constructed and tested for its energy conversion capability under a variety of the exposition angles to the solar irradiation with concurrent examination of the temperature distribution inside proposed structure. It was found that increase of the exposition angle of the structure to an irradiation source causes the decrease of the temperature gradient
$\boldsymbol{\Delta} \mathbf{T}$
between the system layers as well as reduces overall system heating. The temperature gradient's reduction influences negatively the voltage generation process. The experiments showed that for the exposition angles in the range from
$\boldsymbol{0^{\circ}}$
to
$\boldsymbol{45^{\circ}}$
the generated voltage exposition angle dependence is reflected closely by the linear characteristics. It was estimated that the voltage generated by thermoelectric generator structure charged with the optimal load determined and applied, would drop by approximately 0.82% per each 1°degree of the exposition angle increase. The
$\mathbf{Vgen}/\Delta \mathbf{T}$
ratio was established, which takes the upward trend increasing by 4.46
$\mathbf{mV}/{}^{\circ} \mathbf{C}$
for the maximum
$\Delta \mathbf{T}$
and 3.67
$\mathbf{mV}/{}^{\circ} \mathbf{C}$
for the average
$\Delta \mathbf{T}$
with each degree of the exposition angle increase. Evaluated factors and ratios could be used by other researchers for design and evaluation of the similar hybrid systems.