Performance analysis of a hybrid hydrogen production system in the integrations of PV/T power generation electrolytic water and photothermal cooperative reaction

Hydrogen production by solar energy is very promising. In this paper, a hybrid hydrogen production method by combining photothermal cooperative reaction with PV/T power generation electrolysis water is proposed. Although the photothermal cooperative reaction and the PV/T power generation electrolysis water can also use the full spectrum of solar energy for hydrogen generation, and the hydrogen generation efficiencies of the two are 1.223% and 17.339% respectively, but the efficiency of the hybrid hydrogen production method proposed in this paper under the same conditions is 18.49%. In contrast, the hydrogen production method proposed in this paper is more efficient. By establishing the PV/T model, the electrolytic water model and the photothermal cooperative reaction model, the hybrid model hydrogen production efficiency at different PV cell temperatures, at different separation wavelengths λ3 and at different PV cell materials were analyzed and discussed in this paper. In the hybrid model, when reducing the temperature of the PV cell, the increment of the PV power generation is somewhat larger than the reduction of the electrolytic water hydrogen production efficiency, thus the temperature of PV cell should be reduced as much as possible in order to improve the efficiency of the hybrid model. When increasing the separation wavelength λ3, the increment of electrolytic water hydrogen production rate is higher than the decrement of photothermal cooperative reaction hydrogen production rate, thus in order to improve the hydrogen production efficiency of the hybrid model, the separation wavelength λ3 should be increased within the desirable range. When the PV cell material is GaAs, hybrid model hydrogen production efficiency is the highest, which can reach 20.52%. These conclusions could provide thoughts for the subsequent design of more efficient full-spectrum solar hydrogen production methods.