Operating temperature of photovoltaic modules: A survey of pertinent correlations

A simple correlation for the operating temperature of photovoltaic modules of arbitrary mounting

By a careful study of data collected from seven varieties of photovoltaic (PV) module it is demonstrated that a simple modified form of the Hottel–Whillier–Bliss (HWB) equation, familiar from the analysis of flat-plate solar–thermal collectors, can be employed to predict module temperatures within an accuracy comparable to the cell-to-cell temperature differences typically encountered within a module. Furthermore, for modules within the range of construction parameters employed in this study, the actual values of the two modified HWB constants do not appear to depend upon module type. The implication of these results for the accuracy of outdoor module characterization is discussed. Copyright © 2008 John Wiley & Sons, Ltd.

Assessing the outdoor operating temperature of photovoltaic modules

https://pure.ulster.ac.uk/ws/files/11503669/paper_building_integrated_thermal_storage_-_Part_1_v6_clean_2.pdf

Thermal energy storage in building integrated thermal systems: A review. Part 1. active storage systems

Solar Photovoltaic system comprises of photovoltaic (PV) array, converter, inverter and battery storage unit of appropriate capacity to serve the load demand in reliable, efficient and economically feasible manner. The proper selection of technology and size of these components is essential for stable and efficient operation of PV system. Therefore, a number of modeling equations and methodologies for designing a PV system based on application have been developed in order to ensure the optimum performance of the PV system. In this paper, a comprehensive designing process of solar photovoltaic water pumping system, standalone PV system and grid connected PV system is presented. The modeling of PV modules, cell temperature, water pumping system and battery state of charge is tabularized so as to facilitate their utilization for proposing a PV system based on the techno-economic variables and environmental parameters. The financial and reliability parameters for techno-economic size optimization of PV system are also identified and different optimization techniques have been discussed. A state of art literature survey has been presented which is useful in designing and installation of solar PV systems for standalone as well as grid connected power supply.

A review on modeling, design methodology and size optimization of photovoltaic based water pumping, standalone and grid connected system

The bulk of the testing was the characterization of twenty-nine modules according to their nominal operating cell temperature (NOCT) and the effect on NOCT of changes in module design, various residential roof mounting configurations, and dirt accumulation. Other tests, often performed parallel with the NOCT measurements, evaluated the improvement in electrical performance by cooling the modules with water and by channeling the waste heat into a phase change material (wax). Electrical degradation resulting from the natural marriage of photovoltaic and solar water heating modules was also demonstrated. Cost effectiveness of each of these techniques are evaluated in light of the LSA cost goal of $0.50 per watt.

/pdf/thermal-and-other-tests-of-photovoltaic-modules-performed-in-3ekqjswfs0.pdf

Thermal and other tests of photovoltaic modules performed in natural sunlight

Thermal performance of Cassini multilayer insulation (MLI) blankets was characterized in thermal vacuum tests. Effective emittance was derived for the standard and high-temperature layups, with or without micrometeoroid protection standoffs, and for a high-performance duo-layup with staggered seams. The all-Kapton® layup was shown to have a 19% higher effective emittance than the hybrid KaptonMylar® layup, and the duo-layup exhibited a dramatic capability of reducing heat dissipation by 2.6-fold. Several different definitions of effective emittance are discussed, and their relations to distinct hardware-MLI configurations and corresponding modeling techniques clarified. Large temperature differences (up to 70°C) were observed between the center and seam of a blanket. Heat losses in the vicinity of seams are quantified, and a major MLI heat loss mechanism elucidated.

Effective emittance for Cassini multilayer insulation blankets and heat loss near seams

Cassini MLI blankets high-temperature exposure tests

The delay in the launching of the Galileo spacecraft, which was to be launched aboard the Space Shuttle Atlantis, caused by the Challenger accident resulted in a decrease in the Radioisotope Thermoelectric Generator (RTG) power. A change to the Inertial Upper Stage from the more powerful Centaur G-Prime resulted in a trajectory that requires gravity assists, once by Venus and twice by earth. The resulting peak solar intensity of this roundabout trajectory is more than twice the previous design value for the direct trajectory. The resulting changes in solar intensity range and the RTG power output were substantial and forced major thermal design changes. This paper discusses the thermal design and redesign of the Galileo Spun and Despun sciences. Data are presented on the allowable temperatures for the Spun and Despun sciences, the energy balance calculated for the Despun science, and the Despun science test results.

James W. Stultz

Papers

Thermal and other tests of photovoltaic modules performed in natural sunlight

Effective emittance for Cassini multilayer insulation blankets and heat loss near seams

Thermal and other tests of photovoltaic modules performed in natural sunlight

Cassini MLI blankets high-temperature exposure tests

Thermal design of the Galileo spun and despun science