Thermally conductive and electrically insulating EVA composite encapsulant for solar photovoltaic (PV) cell

Abstract

Abstract.A new way of improving the heat dissipating ability and PV efficiency of the solar cells by enhancing the thermal conductivity of the rear EVA layer was reported. The thermal conductivity, electrical resistivity, degree of curing of the EVA encapsulating composites and the PV efficiency of the solar cells are investigated. Filling with the thermal conductive fillers enhances the thermal conductivity of the composites effectively. The thermal conductivity of the filler influences significantly the thermal conductivity of the composite at high filler loading (greater than 20 vol%). Thermal conductivities of the composites filled with SiC, ZnO or BN reach respectively 2.85, 2.26 and 2.08 W/m·K at filler content of 60 vol%. The composites filled with ZnO or BN exhibit superior electrical insulation to those filled with SiC or Al2O3. ZnO can promote the cross-linking reaction of the EVA matrix. The test results indicated that the EVA composite encapsulating rear films filled with thermal conductive fillers are able to improve the PV efficiency and the heat dissipating ability of the solar cell effectively.

Enhancing the thermal conductivity of ethylene-vinyl acetate (EVA) in a photovoltaic thermal collector

“…Heat Generating PV Layer 5 3 which is agreement with the 0.83W/ m·K measured in this study. Lee et al continued to increase the BN concentration up to 60% v/v; however it was found that increased filler increased the stiffness of the material, which could cause problems for manufacture and durability.…”

“…4 The same concept can be applied to photovoltaic cells. A previous study by Lee et al 3 revealed that filler materials increase the thermal conductivity of EVA from 0.23 to 2.85W/(m·K) . For a range of different filler materials, a concentration of 20% v/v resulted in a -0.97% to +5.05% change in power output compared to the parent material.. Kemaloglu et al 5 used Boron Nitride filler with a particle size of approximately 10µm; the conclusion was that conductivity increases with reduced particle size and that nano-sized particles hold promise for the future.…”

“…If the conductivity of the EVA layer on the backside of the PV cell is increased from 0.23W/(m·K) to 2.85W/(m·K), 3 the overall composite conductivity increases by nearly 25% to 1.02W/(m·K).…”

A Review on Thermal Conductivity of Polymer Composites Using Carbon-Based Fillers : Carbon Nanotubes and Carbon Fibers

“…[10]. The improvement of thermal conductivity has been explored for various systems including boron nitride (BN) in polyethylene matrix, ZnO in silicone rubber, metal oxide fillers in ethylene vinyl acetate (EVA) for the solar cell, modified ZnO in EVA, and ZnO in ethylene glycol [11][12][13][14][15].…”

Desenvolvimento de transdutor em fibra óptica com estrutura hí­brida LPG-FBG para medição de propriedades térmicas de materiais.

“…Adicionalmente, a determinação dessas propriedades é de grande importância na utilização de líquidos de arrefecimento compostos por nanofluidos na indústria em geral e automobilística (KOLE; DEY, 2010;CHOI, 1999;LEE et al, 1999), na utilização de espumas de grafite em trocadores de calor em veículos pesados (KLETT; OTT; MCMILLAN, 2000), na otimização energética em sistemas de captação de energia solar (LEE et al, 2008;GAITHO et al, 2009), na utilização de sal fundido como líquido de arrefecimento na área nuclear (JANZ, 1967;SAMUEL, May, 2009;FORSBERG, 2004), na detecção de tumores na área biomédica (AHUJA et al, 1978), entre outras.…”