Green hydrogen production using bifacial solar photovoltaics integrated with high-albedo roof coating & micro-inverter

Green hydrogen is a key factor for the decarbonization of the energy sector and to foster the clean energy
transition but has the highest cost when compared to grey and blue hydrogen. This is due to the high cost of the
generation of energy from renewable sources and the efficiency of the water electrolyzer. Future innovative
energy technologies are needed to boost the power production from solar PV systems, reduce the cost of
renewable electricity and enhance hydrogen production from electrolyzers. The main objective of this study is to
investigate green production enhancement using a bifacial solar PV system integrated with cool roof technology
(high-albedo roof coatings). The best-reflecting surface needs to be determined to maximize the power output
from the bifacial solar PV system and the green hydrogen production. The originality and novelty of this study lie
in the fact that it integrates innovative technologies such as bifacial solar PV and building cool roofs in order to
boost the power generation output and green hydrogen production. The experimental set-up is composed of
bifacial solar PV, a building roof with high solar reflective material, a microinverter, an electrolyzer, a metal
hydride hydrogen tank, and an integrated data acquisition system. The results show that the green, grey, and
white reflecting surfaces exhibit the albedo of 16.76 %, 17.87 % and 24.45 % respectively resulting in 17.26 %,
19.72 % and 28.47 % enhancement in power production by bPV as compared to reference mPV. Further,
whiteboard, patterned wallpaper and cool roof paint coating are assessed and have shown 24.09 %, 29.66 % and
30.27 % rear side irradiance on the bPV as compared to the front side, resulting in 28.10 %, 31.30 % and 33.02 %
increase in energy generation. The results conclude that cool roof paint outperforms the others and enhances the
power output of bPV by 33.02 % resulting in 30.26 g of H2 production as compared to 22.75 g by mPV under the
same conditions. Hence, cool roof paint improves the energy production of bPV solar resulting in high production
of H2.