Thermal and electrical performance evaluation of hybrid air PV/T collector – numerical analysis and experimental study

Figures & data

Figure 1. The cross-sectional view of a PV/T air collector.

Figure 2. Air PV/T experimental device.

Table 1. Specifications of PV panel.

Electrical data	Mechanical data
Module maximum power 250 W Voltage at maximum power point 31.3 V Current at maximum power point 7.99 Amp Open circuit voltage (Voc) 37.7 Short circuit current (Isc) 8.55 Fill factor FF 0.77 Operating temperature 25(°C) Operating radiation 1000 W/m2	Cell type mono crystalline No. of cells and cells arrangement 60 (6 *10) Dimensions (mm) 1698* 983 * 32 mm Weight 20 kg (44.1 lbs) Front cover Tempered glass Frame material Anodised Aluminium Alloy Standard packaging (modules per pallet)20 pcs

Table 2. Specifications of PV/T collectors.

Collector tilt angle (degree) 36° Collector length (mm) 1645 Collector width (mm) 983 Lower duct height (mm) 4.5 Inlet area (mm^2) 4.5 mm *980 mm Plate type Flat plate Cover material Ordinary clear glass, s 0.86 Number of covers 1 Thermal conductivity of Insulation k 0.059 material (Wood panel) Back insulation thickness (mm) 10

Table 3. Uncertainty of measured variables.

Variable	Uncertainty%	Variable	Uncertainty%
Temp	0.223	Current	0.65
Air density	0.1	Voltage	1
Air specific heat	0.1	Solari radiation	1.3
Velocity	2	Power	0.5
Air Viscosity	0.1	Length	0.05

Figure 3. Details the thermocouple positions in the PV/T collector.

Figure 4. (a) Equivalent circuit of the single diode model of PV cell; (b) Theoretical I-V Characteristic of a PV cell.

Figure 5. Schematic representation of thermal resistances in a hybrid air collector.

Figure 6. The simulated and experimental values of short-circuit current during the test day.

Figure 7. The simulated and experimental values of open-circuit voltage during the test day.

Figure 8. The simulated and predicted values of outlet air temperature and the corresponding experimentally measured data during the test day.

Figure 9. The simulated and predicted values of solar cell temperature and the corresponding experimentally measured data during the test day.

Figure 10. Variation short-circuit current and open -circuit voltage as a function of cell temperature and solar radiation.

Figure 11. Variation maximum power as a function of cell temperature and solar radiation.

Figure 12. Evolution of thermal, electrical and overall efficiency, as a function of mass flow.

Figure 13. Evolution efficiencies as a function of time.

Figure 14. Evolution of thermal efficiency as a function of solar radiation.

Figure 15. Evolution of thermal efficiency in wind speed.

Figure 16. Evolution of thermal efficiency as a function of ambient temperature.

Table 4. The efficiencies of PV/T system for T_amb = 300 K, V_w = 1 m/s and G = 700 w/m².

Mass flow rate (kg/s)	PV efficiency ${\eta }_{el}$ % (Sarhaddi et al. 2010)	PV efficiency ${\eta }_{el}$ % $\left[\mathrm{S}\mathrm{i}\mathrm{m}\right]$	Thermal efficiency ${\eta }_{th}$ % (Sarhaddi et al. 2010)	Thermal efficiency ${\eta }_{th}$ % $\left[\mathrm{S}\mathrm{i}\mathrm{m}\right]$	Overall Thermal efficiency ${\eta }_{\mathrm{o}\mathrm{v}\mathrm{e}\mathrm{r}\mathrm{a}\mathrm{l}\mathrm{l}}$ % (Sarhaddi et al. 2010)	Overall Thermal efficiency ${\eta }_{\mathrm{o}\mathrm{v}\mathrm{e}\mathrm{r}\mathrm{a}\mathrm{l}\mathrm{l}}$ % $\left[\mathrm{S}\mathrm{i}\mathrm{m}\right]$
0.001	10	12.13	0	0	26.5	33.69
0.0264	10	12.19	19	6.61	42	40.3
0.0529	10	12.22	23	17	50	50.69
0.079	10	12.24	30	22.8	59	56.49
0.1058	10	12.25	37	25.72	63	59.41
0.132	10	12.28	39	32.35	68	66.04
0.158	10	12.3	40	37	69	70.69
0.185	10	12.31	40.5	41.8	70	75.49
0.211	10	12.32	41	45.6	71	79.29

Figure 17. Sensitivity analysis of the rate of thermal energy output of the PV/T air system for different channel depth.

Table 5. Cost of the system components.

	PV (US $)	TS (US $)	PV/T (US $)
Panels	200	300	200
Thermal insulation material (Bakelite plate)	–	–	45
Fan (AC)	–	7	7
Bracket	20	20	20
Cost Installation	25	25	50
Inverter, cable	110	–	110
Total cost	355	352	432

Figure 18. Costs and revenues.

Sarhaddi, F., S. Farahat, H. Ajam, A. Behzadmehr, and M. Mahdavi Adeli. 2010. “An Improved Thermal and Electrical Model for a Solar Photovoltaic Thermal (PV/T) Air Collector.” Applied Energy 87: 2328–2339. doi: https://doi.org/10.1016/j.apenergy.2010.01.001

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