BAPV array: Thermal modeling and cooling effect of exhaust fan

Abstract

Thermal modeling and mitigation methods of thermal effects for building-applied photovoltaic (BAPV) systems have become important for the industry in order to predict energy production and lower the cost per kilowatt-hour (kWh). The operating temperature of BAPV modules can reach as high as 90 o C in desert climatic conditions such as Phoenix, Arizona. These high operating temperatures will have a significant impact on the power generation and a dramatic impact on the lifetime of PV modules. The traditional method of minimizing the operating temperature of BAPV modules has been to include a suitable air gap for ventilation between the rooftop and the modules. The previous work at Arizona State University (ASU) was aimed at identifying the effects of various air gaps on the temperature of individual BAPV modules. The goal in this work was to develop a thermal model for a small residential BAPV array consisting of 12 closely packed identical polycrystalline silicon modules at a single air gap of 2.5 inches from the rooftop of 23 o tilt with ceramic tiles. The thermal model coefficients for the array are empirically derived from a simulated field test setup at ASU and are presented in this paper. Additionally, this project investigates the effects of cooling the array with a small 40-watt exhaust fan. The fan had only a small effect on power output or efficiency for this 2.5-inch air gap array, but provided slightly lower temperatures (higher lifetime) and better temperature uniformity (higher power output) across the array. BACKGROUND

Field testing of thermoplastic encapsulants in high‐temperature installations

“…Modules are often mounted to encourage air flow. Even when building‐integrated, a module is not likely to be mounted to a well‐insulated roof surface (as chosen here to simulate a worst‐case scenario) because such a configuration would run hot, compromising efficiency and PV durability . We acknowledge that the high temperatures in Figures and , although rare, could exist for PV modules deployed at hot desert locations.…”

“…Noting the absence of creep beyond day 110 in AZ, where the maximum temperature did not exceed 90°C, and that the Colorado‐deployed module barely crept while rarely reaching temperatures above 90°C indicates that creep is possible for uncured EVA when the maximum module temperature approaches around 90°C, Figure . It is unlikely that one would expect to directly detect encapsulant creep in an outdoor‐deployed module considering that: (1) module temperatures above 90°C will only occur in very hot environments when modules are mounted with very minimal air flow for heat transfer on the backside , (2) significant temperature nonuniformities exist at the module periphery, restricting creep, (3) only the NC‐EVA module, which has a very low viscosity, crept, and (4) the glass on these modules was unconstrained.…”

“…The tests here were conducted to examine modules fielded at the highest temperatures expected for PV systems integrated into a well‐insulated roof. Rack‐mounted modules would clearly be expected to have a temperature ~15°C lower than building‐integrated or building‐applied PV systems . The only ways to achieve higher temperatures would be if: modules were mounted in an even hotter environment than Phoenix, AZ, were mirror‐augmented, mounted near a heat source such as a vent, or part of a much larger building‐integrated array and mounted with no convective cooling on the backside on a well‐insulated roof.…”

Investigation of the Photon to Charge Conversion and Its Implication on Photovoltaic Cell Efficient Operation

“…A review on PV cooling technologies regarding the three-heat transfer mechanism (convection, conduction, and radiation) can be found in literature [33]. The optimization of operating temperature increases in the lifetime of the system by decreasing the thermo-mechanical fatigue for typical failure mechanisms [34] and has a significant influence on PV efficiency output. The correlation between the examined PV cell temperature and the environmental independent variables is found by a regression analysis [34] and for fixed period measurements.…”

Sistem Pemantauan Gas Benzena dengan Aplikasi Blynk

“…Exhaust Fan adalah sebuah alat untuk menyedot atau menyaring udara yang tidak kita inginkan supaya keluar, seperti udara sisa pembakaran atau gas dari suatu ruangan. Proses kerjanya dengan memiliki lekukan kipas yang mengarah keluar maka saat beroperasi akan mengeluarkan udara dari dalam (Hrica, Chatterjee & TamizhMani, 2011).…”