Solar Energy, Vol.215, 198-205, 2021
Application of a fixed-receiver Linear Fresnel Reflector in concentrating photovoltaics
Among the numerous proposals for concentrator design in concentrating photovoltaics, fixed-receiver linear Fresnel reflectors (with a fixed receiver and multiple mirror strips at ground level, rotating on multiple parallel axes) seem to have been quite neglected so far in the literature. In this work we present and discuss properties and possibilities of a fixed-receiver LFR for concentrating photovoltaics, adopting flat mirrors as primary reflectors, integrated with a simple cooling system. Thanks to their technical characteristics, fixed-receiver LFRs are especially well suited for the realization of medium/large scale CPV power plants, in view of the foreseeable use of PV as one of the main electricity sources. The annual performance in a desertic site inclusive of the energy used for cooling is computed from a thermal simulation of the system, and it is compared to the performance of a non-concentrating PV system. We show that the use of Fresnel concentrators is currently competitive with non concentrating systems for medium-to-large plants in suitable locations, and could be an advantageous alternative in the case of a rise in price of PV panels, or as the effect of a price drop in mirrors and Fresnel components due to scale economy. Moreover, CPV Fresnel concentrators do not suffer from drawbacks usually associated with thermal concentrating technologies, such as high working temperatures, the need for large structures and for an external power block, and management complexity. The proposed technology is easily achievable and it is not much more complex to manage than a non-concentrating PV system.