**5.1. Environmental benefits**

highest Nusselt number (i.e. optimum heat transfer) under the influence of non-uniform magnetic field. In the presence of magnetic field, addition of nanoparticles can improve the heat

**Intensity Cooling Fluid Electrical Efficiency Thermal Efficiency**



 SiC-Water 16.90% 8% SiC-Water 10.90% 48% CuO-Water 16% 6% CuO-Water 10% 41%

200 Water 11.90% 4% 1000 Water 8.40% 31%

Narrow channels offer higher enhancement in the heat transfer coefficient whereas the wide channels depict instabilities in lateral heat transfer. Roughness in the pipes also affects the magnitude of heat transfer. Pipes with greater roughness magnitude offer greater heat transfer due to the increased contact surface. In order to achieve higher performance, the temperature distribution inside the channel should be held uniform, the temperature should be kept low and the pressure drop should also be as minimum as possible [49]. Considering the **Table 3**, helical channel performs best because of greater surface contact of nanofluid with the rear surface of PV unit.

**Flowrate Channel** 

Boehmite Water 0.01 wt% 300 ml/min Straight Decreased from

Boehmite Water 0.1 wt% 200 ml/min Straight 18.33°C

Boehmite Water 0.1 wt% 200 ml/min Helical 24.22°C

**Geometry**

**Effect on Temperature**

62°C to 32.5°C for flowrate 0–300 ml/min

Temperature Reduction

Temperature Reduction

**Effect on Electrical Efficiency**

27.12% increase compared to Conventional PV System

20.57% increase compared to conventional PV System

37.67% increase compared to Conventional PV System

transfer properties of nanofluids [68].

**Table 2.** Effect of irradiance on efficiency [38].

O3

O3

**4.7. Channel geometry**

**Researcher Nanoparticle Base** 

**Table 3.** Effect of channel geometry on efficiency.

Karami and Rahimi [34]

Karami and Rahimi, [57]

**fluid**

**Concentration**

200 Al2

52 Microfluidics and Nanofluidics

1000 Al2

Fossil fuel based power plants emit tons of noxious gases that detriment the environment. Since the solar power plants are emission free, production of electricity via this method can eliminate the emission of 16,974,57 tons of CO2 [58]. Hassani et al. [26] evaluated that nanofluid based PV/T systems can omit the emission of 448 kg *CO*<sup>2</sup> *<sup>m</sup>*−2 *yr* −1 .
