A review on Linear Fresnel Reflector (LFR) as a solar line concentrator in polygeneration for low-medium temperature applications among the rural livelihoods

Abstract

Rural electrification is exhaustive, costly, and lacks paybacks while renewable energy interventions are policy-influenced usually taking a top-down approach. The livelihood activities are energy intensive, while specific in nature and requirement. There exists an inherent nexus among rural livelihoods between energy-water-food, which is often not explored., while polygeneration and cogeneration methods can benefit this nexus. Parabolic trough collectors (PTC), heliostats, and Linear Fresnel Reflectors (LFR) are solar concentrators used for high-temperature steam generation. The LFR has the advantage of easy installation, reduced structures, good optical efficiency, flexible designs, and direct steam generation at a temperature range of 80 C - to 400 C, which can be a techno-commercial competitor for evacuated tube collectors (ETC) and PTC. An extensive review of the energy requirement in various rural livelihoods and the potential of solar concentrators with a focus on the PTC and LFR, with their limitation and the advantages are done. While the LFR can match the optical efficiency of the PTC, it is found that the two-phase flow and the entropy generation are the limitations, while easy installations, custom designs, and reduced structures are the advantages over the PTC. The review and comparison have found that there is a difference between the thermal energy produced per mirror area and the land area with respect to PTC and the LFR. Concerning application in the diary industry, it is found that with the modifications in LFR, the thermal energy produced per square meter of land by LFR can be 300 MW_h/m^2, while the PTC produces 225 MW_h / m² in comparison with 180 MW_h /m². This shows that LFR modifications including reduced receiver height, inclined mirror, and double reflectors can make it the ideal solar collector for rural livelihood applications for low-medium heat requirements.