Exergy analysis of solar energy systems - Solar Energy Sciences and Engineering Applications - page 111

Figure 3.3.10 Effect of increase in solar flux on overall system energy and exergy efficiencies.
an increase in solar flux from 600 W/m 2 to 1200 W/m 2 . The thermal energy and exergy
efficiencies are found to be increasing from 38.73% to 44.57% and 7.23% to 14.06%,
respectively. The effect of an increase in solar flux on overall energy and exergy efficien-
cies is also studied and is illustrated in Figure 3.3.10. The overall energy and exergy
efficiencies increase from 48.19% to 54.03% and 17.21% to 24.03%, respectively
with an increase in solar flux. The results show that energy and exergy efficiencies are
dependent on solar flux received by the solar PV/T system.
3.3.3 Case study 3: Exergy assessment of an integrated
solar PV/T and triple effect absorption cooling system
for hydrogen and cooling production
In this case study, a detailed energy and exergy model of an integrated concentrated
solar PV/T and triple effect cooling system is presented. Operating parameters such
as solar flux, area, and air inlet temperature are varied to see their effect on overall
energy and exergy efficiencies, the power produced by the solar PV panels, the rate of
hydrogen produced, and energy and exergy COPs.
3.3.3.1 System description
In this case study, we have studied an integrated concentrated solar PV/T absorption
cooling system for the cooling and hydrogen production as shown in Figure 3.3.11.
In this integrated system, concentrated solar PV/T is used to produce power and heat.
Power produced is supplied to the electrolyzer and the pump in the cooling cycle.
The electrolyzer is utilized to break the water molecule bond. As the water molecule
breaks, it splits into hydrogen and oxygen. The hydrogen molecules are taken out of
the electrolyzer and are stored in a tank for later use as an energy source. The high
temperature air coming out of solar PV/T is fed into the HTG of the absorption cooling