Daria Freier

Design method for nonimaging solar photovoltaic concentrators using genetic algorithms.

Off-grid solar chargers are one of the ways forward to achieve universal access to affordable, reliable, sustainable and modern electricity. To achieve this goal, the sustainability aspect of the solar chargers must be further improved. Nonimaging, static solar photovoltaic (PV) concentrators reduce the amount of PV material and thus the embodied energy and greenhouse gas emissions of the solar PV panel, improve its recyclability and reduce the use of hazardous chemicals during its manufacturing, recycling and disposal stages. A novel nonimaging solar PV concentrator named circular rotational square hyperboloid (CRSH) was recently proposed for portable solar systems for developing countries. To further reduce the material usage and production time of the concentrator while achieving an optical concentration ratio above 3× within the angles of incidence of ± 40°, the parameters of the design were optimised using genetic algorithms. The optimisation parameters are discussed and the influence of the objective function on the optimised design is presented. The genetically optimised circular rotational square hyperboloid (GOCRSH) concentrator shows an improved gain-to-volume ratio compared to the CRSH and to several nonimaging solar photovoltaic concentrators proposed for building integrated concentrated PV.Off-grid solar chargers are one of the ways forward to achieve universal access to affordable, reliable, sustainable and modern electricity. To achieve this goal, the sustainability aspect of the solar chargers must be further improved. Nonimaging, static solar photovoltaic (PV) concentrators reduce the amount of PV material and thus the embodied energy and greenhouse gas emissions of the solar PV panel, improve its recyclability and reduce the use of hazardous chemicals during its manufacturing, recycling and disposal stages. A novel nonimaging solar PV concentrator named circular rotational square hyperboloid (CRSH) was recently proposed for portable solar systems for developing countries. To further reduce the material usage and production time of the concentrator while achieving an optical concentration ratio above 3× within the angles of incidence of ± 40°, the parameters of the design were optimised using genetic algorithms. The optimisation parameters are discussed and the influence of the objectiv...

Effect of diffuse radiation on the performance of a rotationally asymmetrical optical concentrator

This paper evaluates the performance of a recently patented rotationally asymmetrical dielectric totally internally reflective concentrator (RADTIRC) under diffuse radiation. The RADTIRC has a geometrical concentration gain of 4.969 and two half acceptance angles of ± 30° and ± 40° along the x-axis and z-axis respectively. Simulation and experimental work have been carried out to determine the optical concentration gain under diffuse radiation. It was found that the RADTIRC has an optical concentration gain of 1.94 under diffuse irradiance. The experimental results for the single concentrator showed an optoelectronic gain of 2.13, giving a difference of 9.8% due to factors such as the presence of direct radiation during experiments, the increase in diffuse radiation due to the reflection from surrounded buildings as well as from the ground reflection.