Energetic, exergetic and exergeoeconomic assessment of a hybrid solar/biomass poylgeneration system: A case study of a rural community in a semi-arid climate

Abstract

Abstract In this work, a polygeneration system combining a compound parabolic collectors’ solar field, a thermocline thermal energy storage system, biomass boilers, an ORC, a reverse osmosis unit, a vapor compression cycle and a hybrid air/water condenser, is investigated considering energetic, exergetic and exergoeconomic indicators. The studied system is assessed for the case of a 40 households community located in a semi-arid region (Benguerir, Morocco) characterized by a good solar potential (DNI of 2239 kWh/m2/y) and the presence of brackish groundwater. Results show that the proposed system could meet a significant part of the community’s requirements with an annual biomass consumption of 342 T and an average solar contribution of 20%. The weekly plant’s overall energy efficiency is varying between 15 and 44%, while its corresponding exergy efficiency is in a range between 5 and 2.9%. Results also report that the use of R1336mzz(Z) as an ORC working fluid could reduce the weekly biomass consumption by 13.4%, while the use of R1234ze(Z) could lead to an increase of this value by 8.94%. Finally, a parametric study highlighted that considerable cost reductions should be fulfilled at the solar field’s level to make its aperture increase economically viable.