Integration of dye-sensitized solar cells (DSC) on photobioreactors for improved photoconversion efficiency in microalgal cultivation

Outdoor industrial-scale microalgae cultivation is limited by several factors, among which a low efficiency of overall light energy conversion plays a key role, mainly due to photosaturation and photoinhibition under high irradiations. This work aims at improving the overall photoconversion efficiency in a microalgal production photobioreactor (PBRs), by exploiting an advanced photovoltaic (PV) technology. A semi-transparent dye sensitized solar cells module (DSC) is placed on the irradiated surface, thus absorbing part of the incident light to produce electricity, while transmitted photons are used by algal cells for photosynthesis. Experiments are carried out in a continuous laboratory scale flat-panel PBR, at different constant light intensities and under a day-night irradiation regime, to ascertain the performances of this combined PV-PBR system in terms of biomass productivity and overall photoconversion efficiency, compared to traditional transparent PBRs. The results obtained show that the configuration proposed, combining biomass production with innovative photovoltaics technology, could be a valuable way to improve light energy utilization and efficiency in microalgal production.