Photovoltaic-electrolysis systems

Khaselev, O., Bansal, A., and Turner, J.A., High-efficiency integrated multijunction photovoltaic/ electrolysis systems for hydrogen production, Int.. Hydrogen Energ., 26,127,2001. 

Fischer M (1986) Review of hydrogen production with photovoltaic electrolysis system. Int J Hydrogen Energy 11 495-501... 

Esteve D, Ganibal C, Steinmetz D, Vialason A (1980) Performance of a photovoltaic electrolysis system. Proc 3 word Hydrogen Energy Conference, Tokyo. V. 3, pp.l583-1603... 

Delahoy AE, Gao SC, Murphy OJ, Kapur M, Bockris JOM (1985) A one-unit photovoltaic electrolysis system based on a triple stack of amorphous silicon (pin) cells. Int J Hydrogen Energy 10 113-116... 

Photoelectrochemical water splitting Photocatalytic water splitting Coupled photovoltaic - electrolysis systems Thermochemical conversion Photobiological methods Molecular artificial photosynthesis Plasma-chemical conversion Mechano-catalytic, magnetolysis, radiolysis, etc. 

Fig. 8. Schematic represenlaticm of a photovoltaic-electrolysis system based on a simply...

Fig. 8.9 Schematic diagram of PV-electrolysis systems proposed for solar water splitting (a) Electricity generated from photovoltaic cell driving water electrolysis (b) PV assisted cell with immersed semiconductor p/n junction as one electrode.

The photovoltaic power system consists of 160 single pedestal concentrator arrays, each containing 256 circular silicon solar cells (64 modules). Each module contains 4 Fresnel lenses, for a sunlight concentration of ca. 33 times over solar cells. These 64 branches are connected in parallel to provide 350 kW of peak power. The electrolysis system is a commercially available HS 2000 electrolyzer with the cell area 0.2 rrfi (No. of cells 144). Electrolyte is 30% KOH solution, system pressure 6 bar, working temperature 100 °C. The plant also contains a grid operated rectifier for initial start-up and special testing. 

Finally, one more type of water splitting cells should be mentioned, namely integrated photovoltaic-electrolysis (PV-PEC) cells. In this type of devices, the photovoltaic cell and the electrolyser are combined into a single system, in which the light-harvesting solar cell is one of the electrodes. Very often, thin-film solar cells fabricated by the cold plasma deposition method are employed in the PV-PEC devices (Kelly Gibson, 2006). A diagram of such a system with a simply a-Si H solar cell is shown in Fig. 8. There is no doubt that the role played by the cold plasma deposition technique in the creation of such systems is unquestionable (see Sec. 4.1.). 

PV via electrolysis. In Canada, the National Research Council in Vancouver is also demonstrating the combination of hydrogen PEM fuel cells with photovoltaic and electrolyser powering systems as a back up power for buildings. 

H2 Refuelling station in Barcelona. Electrolysis production of hydrogen, which will be supplied at high pressure to three buses participating in the European CUTE project. It will be the first hydrogen production plant with a solar photovoltaic system, producing 10% of electricity needs. 

Considerable research effort Is being placed Into the development of renewable resources. Although steady progress is being made in areas such as photovoltaics, there are numerous discoveries yet to be made. At this time, the cost of producing electricity via electrolysis of water using photovoltaics is about 0.12/kWh. In order to be competitive, this cost must be reduced substantially via improved efficiency of the overall system and reduced cost resulting from mass production. 

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