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The characteristics of concentrator photovoltaic modules based on a 120 × 120 mm Fresnel lens with secondary concentrators in the form of hollow aluminum focons with internal mirror walls are studied. The optimal sizes and configurations of secondary concentrators are determined to increase the efficiency of focusing systems of concentrator modules. The maximum value of the allowable misorientation angle was obtained, equal to ±0.75°, corresponding to a power drop to a level of 90% relative to the maximum power value of the concentrator photovoltaic module at normal beam incidence. For a module with the most efficient focon 40 mm high and side face slope angles of 17°, the maximum efficiency of the module under laboratory conditions was obtained, equal to 35.15%. Under natural conditions, the efficiency value reached 33.8%. The results obtained correspond to the level achieved for the best foreign analogues. [ABSTRACT FROM AUTHOR]

Concentrated photovoltaic (CPV) systems can achieve high energy conversion efficiencies due to their use of concentrating optics and highly efficient solar cells; however, power losses arising from the front surface reflection and metallization shading typically contribute a significant fraction to the total power loss for these devices. In flat silicon photovoltaic (PV) modules, the front‐metal finger shape is often shaped to minimize shading losses. Finger shape is even more relevant for CPV cells where the current density and front metal shading are much higher. This study compares the optical performance of five light management finger designs in CPV systems with two different refractive homogenizers. The optical efficiency and loss analysis were determined using ray‐tracing simulations. It is shown that shaped, light diverting metal fingers can improve the optical efficiency in CPV systems by up to 9.9% absolute compared to rectangular fingers, corresponding to an absolute cell efficiency increase of 3.0%. Although sharp edged triangular finger structures may be challenging to fabricate, significant optical gains can still be achieved with trapezoid or rounded cap finger shapes. [ABSTRACT FROM AUTHOR]

Improving efficiency, controlling cost and reducing the temperature of solar cells are great challenges for linear concentrated photovoltaic/thermal systems (LCPV/T). In this work, we report a new design with a linear Fresnel lens as the primary optical element and an additional multi-functioned solar collector tube as the secondary optical element. With such design, the low-cost solar collector tube acts multiple roles simultaneously, i.e., lens, spectral beam-splitting filter and heat collector. It was demonstrated that the addition of such multi-functional solar collector tube in LCPV/T system can significantly increase the irradiation uniformity and decrease the average temperature of photovoltaic (PV) module under the same thermal condition, which results in the improved electricity output performance of PV module. Under the solar irradiance and ambient temperature for a typical daytime, the average electrical, thermal and total energy efficiencies of the proposed system are 11.39%, 64.72% and 76.11%, respectively. Our work should be of guidance for the design of LCPV/T system with high efficiency, long-life and low cost. [Display omitted] [ABSTRACT FROM AUTHOR]

• Novel CPV/T system with liquid spherical lens as secondary optical element. • Secondary optical element and spectral beam splitting filter are merged into one. • Irradiation unavailable to solar cell is used for heating electrolyte. • A solar-to-hydrogen efficiency of 22.7% is achievable in experiments. How to efficiently convert solar radiation into energy sources for easy storage and consumption is an urgent issue. Although concentrated photovoltaics can achieve high efficiency, it places higher demands on the optical system and heat management. Herein, a new design is presented where a liquid spherical lens acts as a secondary optical element of the concentrating solar system, refracting the light beam while participating in spectral beam splitting. The radiation energy unavailable for solar cells is harvested by the liquid spherical lens through spectral beam splitting which serves to raise the temperature of the electrolyte. Compared with the conventional concentrated photovoltaic coupled electrolytic hydrogen production system, the addition of a liquid spherical lens improves the solar cell heat dissipation while increasing the operating temperature of the electrolyzer, achieving higher solar-to-hydrogen efficiency. The system with this design obtains a solar-to-electricity efficiency of 31.7% as verified by indoor experiments. The solar-to-hydrogen efficiency of the system achieved an average value of 22.1% and a benchmark maximum value of 22.7% during 7 h of continuous operation. The solar-to-hydrogen efficiency is improved by at least 10% compared to the design that separates the secondary optics from the spectral beam-splitting filter. Compared with existing systems employing commercial CPV modules, the efficiency is improved by at least 6% benefiting from the rational distribution of the spectrum by the liquid spherical lens. [ABSTRACT FROM AUTHOR]