Environmental Life-Cycle Analysis of Hybrid Solar Photovoltaic/Thermal Systems for Use in Hong Kong

Table 1

Collector and technical design data of free-stand PV/T system.

Design parameters	Data
Glazing (low-iron glass)
Thickness	0.004 m
Emissivity	0.88
Extinction coefficient	26/m
Refraction index	1.526
Depth of air gap underneath	0.025 m
PV encapsulation; (TPT + EVA + solar cell + EVA + TPT + silicon gel)
Solar cell type	single-crystalline silicon
Cell area	1.11 m^2
Cell electrical efficiency at STC	13%
Solar cell temperature coefficient	0.005/K
Emissivity	0.8
Absorptivity	0.8
Packing factor (wrt glazing)	63%
Thermal absorber (Aluminum)
No. of flat-box absorber module	15
Absorber module size	0.105 × 1.38 × 0.012 m
No. of header	2
Header size	1.575 × 0.025 (dia.) × 0.002 (thick) m
Thermal insulation layer (glass wool)
Thickness	0.03 m
Back cover (galvanized iron)
Thickness	0.001 m
Water tank and connecting pipes
Water storage capacity	155 kg
Tank length	1.2 m
Tank diameter	0.21 m
Pipe diameter	0.015 m
Thickness of insulation layer at tank	0.025 m
Thickness of insulation layer on pipe	0.02 m