T. Bergene, THE EFFICIENCY AND PHYSICAL PRINCIPLES OF PHOTOLYSIS OF WATER BY MICROALGAE, International journal of hydrogen energy, 21(3), 1996, pp. 189-194
Citations number
50
Categorie Soggetti
Energy & Fuels","Environmental Sciences","Physics, Atomic, Molecular & Chemical
By a simple argument, the theoretical upper efficiency of the biophoto
lytic splitting of water into molecular hydrogen and oxygen by microal
gae is found to be 0.11. By considering non-ideal conditions such as t
he transmission and reflection of solar photons, the realistic upper e
fficiency is found to be approximately 0.06-0.08. The theoretical effi
ciency is further seen in connection to mechanisms securing charge tra
nsfer and charge separation (Marcus theory), and the process is primar
ily a non-ideal one in a thermodynamic context. The importance of this
fact is stressed because it is shown to be essential regarding the fu
nctionality under various illumination intensities for photosynthesis
in vivo. Fuel-generating processes are discussed from a general thermo
dynamic point of view, and are found to differ in a fundamental way re
garding the potential and current from those involving photovoltaic so
lar cells. Finally, photolysis of water by microalgae is compared with
PV-assisted electrolysis and photoelectrochemical cells on the basis
of efficiencies.