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Methodology is described that uses relative measurements to estimate the degradation rates of PV modules in the field. The importance of calibration and cleaning is discussed. The number of years of field measurements needed to measure degradation rates with data from the field is cut in half using relative comparisons.
Abstract not provided
Literature describes various methods for determining a series resistance for a photovoltaic device from measured IV curves. We investigate use of these techniques to estimate the series resistance parameter for a single diode equivalent circuit model. With simulated IV curves we demonstrate that the series resistance values obtained by these techniques differ systematically from the known series resistance parameter values used to generate the curves, indicating that these methods are not suitable for determining the series resistance parameter for the single diode model equation. Furthermore, we present an alternative method to determine the series resistance parameter jointly with the other parameters for the single diode model equation, and demonstrate the accuracy and reliability of this technique in the presence of measurement errors.
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We describe and compare two methods for modeling irradiance on the back surface of rack-mounted bifacial PV modules: view factor models and ray-tracing simulations. For each method we formulate one or more models and compare each model with irradiance measurements and short circuit current for a bifacial module mounted a fixed tilt rack with three other similarly sized modules. Our analysis illustrates the computational requirements of the different methods and provides insight into their practical applications. We find a level of consistency among the models which indicates that consistent models may be obtained by parameter calibrations.
What standard tests are required for commercializing a new PV module technology such as perovskite photovoltaics? This summary document provides answers in the areas of (1) quality assurance for manufacturing, (2) safety and reliability testing, and (3) performance characterization.
We describe and validate a method for modeling irradiance on the back surface of bifacial PV modules at the scale of individual cells using view factors. We compare model results with irradiance measurements on the back of PV modules in various configurations. Our analysis illustrates the relative accuracy of the model as well as the potential variation in back surface irradiance among the cells.
A supported PV assembly may include a PV module comprising a PV panel and PV module supports including module supports having a support surface supporting the module, a module registration member engaging the PV module to properly position the PV module on the module support, and a mounting element. In some embodiments the PV module registration members engage only the external surfaces of the PV modules at the corners. In some embodiments the assembly includes a wind deflector with ballast secured to a least one of the PV module supports and the wind deflector. An array of the assemblies can be secured to one another at their corners to prevent horizontal separation of the adjacent corners while permitting the PV modules to flex relative to one another so to permit the array of PV modules to follow a contour of the support surface.
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Photovoltaic (PV) technology is one of the most promising technologies for improving energy security and mitigating climate change. The PV market is growing rapidly, and further market expansion is expected all over the world. In addition to its positive impacts on energy security and climate change, PV technology is also among the most environmentally friendly technologies of all energy and electricity generation technologies, particularly when evaluated from a life-cycle viewpoint, including end-of-life management. This means that proper end-of-life management is an indispensable issue for 'clean' energy technologies. All technologies eventually degrade to where they enter their end-of-life stage, eventually requiring replacement. PV modules have a useful lifespan of approximately 30 years. With PV deployment increasing exponentially, the number of PV modules that reach the end of useful life will also greatly increase after the time lag of operation, accumulating proportionately as waste. A report published by International Energy Agency Photovoltaic Power Systems Programme (IEA PVPS) Task12 and the International Renewable Energy Agency (IRENA) in 2016 projected waste PV modules globally to amount to 1,7-8,0 million tons cumulatively by 2030 and to 60-78 million tons cumulatively by 2050. Generally, sustainable waste management offers opportunities known as the 3Rs: reduce, reuse, and recycle. When a product cannot be repaired or reused, recycling is the next preferable option before disposing as waste. In anticipation of the large volume of waste PV modules, and to retain PV's position as a clean energy technology, PV module recycling has become an important emerging topic, and various discussions and activities have been conducted and developed by governments, organizations, and companies. (Discussions on the topic of PV module reuse are considered to be less mature.) The EU Waste Electrical and Electronic Equipment (WEEE) Directive revised in 2012 (2012/19/EU) addresses the waste management of all electronics, including waste PV modules, in the EU member states. It requires 75%/65% (recovery/recycling rate) of waste PV modules by mass to be recycled through 2016, then increases to 80%/75% through 2018 and to 85%/80% thereafter. In addition to such a regulatory scheme, it is obvious that recycling technologies must be available to meet the increasing requirements of WEEE. Available recycling facilities that treat PV modules can meet current WEEE requirements; additional research and development (R&D) is required to meet subsequent WEEE requirements at reasonable cost. This report aims to provide an international survey of trends related to the development of PV module recycling technology from the perspective of both the private and public sectors. For the private sector, we review patents, as patent filing has been increasing since 2011. For the public sector, we review R&D plans and investments made by many countries active in PV module recycling technology development. Because it takes a long time to develop and commercialize new technologies, we hope that this report will accelerate technology development through transparent sharing of status and insight pertaining to the development of PV module recycling technologies. Managing end-of-life PV modules to recover valuable materials that can displace virgin ones is an important step toward meeting the challenge of sustainabiliy.
Research on PV module longevity shows that with lower degradation rates and better encapsulation, PV modules can significantly outlast their current life expectancy of 25-30 years. The focus of this study is on alternative CdTe PV module back-contact and encapsulation materials that show the potential of increasing module operation lives from 30 to 40 and 50 years. Life-cycle-analyis shows that some alternative materials may slightly increase cradle-to-gate environmental impacts per m2 of module, but increased operational life more than counterbalances such impacts. The life-cycle carbn footprint of systems operating under average US insolation conditions of 1800 kWh/m2/yr is reduced from 10 gCO2eq/kWh to 6 gCO2eq/kWh when the operation life increases from 30 to 50 yrs. Similar reductions are noted for all life-cycle impact indicators, whereas the EROI of the considered system increases from 67 to 177 as life increases from 30 to 50 yrs.
Abstract not provided.
As the photovoltaic industry has grown, the interest in comparative accelerated testing has also grown. Private test labs offer testing services that apply greater stress than the standard qualification tests as tools for differentiating products and for gaining increased confidence in long-term PV investments. While the value of a single international standard for comparative accelerated testing is widely acknowledged, the development of a consensus is difficult. This paper strives to identify a technical basis for a comparative standard.
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The width-tapered cantilever beam method is used to quantify the debond energy (adhesion) of encapsulant and backsheet structures of 32 modules collected from the field. The collected population of modules contains both those that have remained intact and those with instances of either or both encapsulant and backsheet delamination. From this survey, initial threshold values (an adhesion value above which a module should remain intact throughout its lifetime) for encapsulant and backsheet interfaces are proposed. For encapsulants this value is ~ 160J/m 2 and for backsheets ~ 10J/m 2 . Here, it is expected that these values will continue to be refined and evolve as the width-tapered cantilever beam method gets adopted by the PV industry, and that they may aid in the future improvement of accelerated lifetime tests and the development of new, low-cost materials.
Thin-film photovoltaic modules are known to exhibit light-induced transient behavior which interferes with accurate and repeatable measurements of power. Typically power measurements are made after a light exposure in order to target a 'light state' of the module that is representative of outdoor performance. Here we show that the concept of a unique light state is poorly defined for both CIGS and CdTe modules. Instead we find that their metastable state after a light exposure can depend on the temperature of the module during the exposure. We observe changes in power as large as 5.8% for a 20 degrees C difference in light exposure temperature. These results lead us to conclude that for applications in which reproducibility and repeatability are critical, module temperature should be tightly controlled during light exposure.