Publish Time: 2022-09-08 Origin: Site
As the core devices of photovoltaic power generation, the quality of photovoltaic or PV modules has attracted much focus, and whether they can achieve the predicted service life is typically questioned. Why are so many market elements that don't satisfy the life span? What exactly is the issue with "temporary" components?
Today, many businesses give 2 types of guarantees for PV modules. One is a minimal item service warranty, and the warranty duration is mostly 10 or 12 years. The restricted electrical performance, the maximum outcome power service warranty, is usually a 25-year direct warranty. Some businesses offer a 30-year service warranty for unique kinds of modules (such as double-glass modules) to boost the competitiveness of items. Considering that modules make up the greatest percentage of system costs, the design life of a photovoltaic nuclear power plant is typically the optimal power warranty years of the components.
Fairly talking, it can not be financially made use of if the anticipated life span of a component is established to be 25 years or if the maximum outcome power of the module is attenuated to 80% of the initial power.
In reaction to the market's worries, Jianheng Qualification Facility has been performing appropriate testing and study jobs. In the last few years, incorporated with other power station screenings, Jianheng has knowingly accomplished targeted screening and evaluation by using components of various kinds and different environment areas. Figure 1 reveals that Jianheng selected 21 different kinds and types of components in each environment area among 20 power plants situated in my country's sub-humid, cozy, chilly, and various other photovoltaic applications, as well as an overall of 63 components have maximum power depletion Level testing as well as evaluation of outcomes.
1) According to the appointing time, the example elements are separated into three grades, consisting of the commissioning time within 1 year, about 3 years, and also concerning 5 years.
2) Import both indications of the "Maximum Power Depletion Mean Index" as well as the "Maximum Power Attenuation Extreme Worth Index" to measure the depletion level of the maximum power of the component relative to the guaranteed worth and also contrast horizontally and vertically. Amongst them, "Maximum Power Depletion Mean Index" describes the proportion of the mean maximum power attenuation rate of a certain power plant and a solitary design "sample group of sampling parts" to the ensured optimum power attenuation value (direct computation) for the corresponding duration; "Optimum Power Attenuation Extreme Worth Index" Describes the ratio of the maximum value of the maximum power attenuation rate to the assured worth of the depletion price of the equivalent period in a power station as well as a single model "example group of sampling elements."
3) Compute the maximum power depletion price of the component according to the nominal power; during information handling, the dimension uncertainty of the maximum power is not considered.
4) Examining elements with the obvious look and inner top quality flaws are removed during information processing.
5) The difference between the first measured and the nominal power and the influence of dimension unpredictability is ruled out. Although it is an analytical outcome, there is still a variance.
The average worth of the "Optimum Power Attenuation Mean Index" of the 63 elements examined by the accreditation is 0.71. Amongst them, there are 19 sorts of elements with an operating time of less than one year, and the "mean index of optimal power attenuation" is 0.71; there are 32 types of components with an operation time of concerning 3 years, and the "mean index of optimal power depletion" is 0.71; There are 12 sorts of components around 2010, and the "Mean Index of Maximum Power Attenuation" is 0.72, which implies that the typical power attenuation level of the components is dramatically better than the guaranteed value. Taking a polysilicon module with a running time of regarding 5 years as an example, the insured value of the maximum power depletion of the module after competing 5 years is not greater than 5.3%, calculated based upon the direct guarantee value of no greater than 2.5% in the first year and no greater than 0.7% in each subsequent year., the "Optimum Power Depletion Mean Index" is 0.72. The typical value of the actual maximum power attenuation of the part is 3.98%.
From this set of information, the ordinary power depletion degree of the module is far better than the assured worth; in addition, for the modules with running times of 1 year, 3 years, and also 5 years, the distinction in the "maximum power depletion suggest index" is little. The straight projection is just from the optimal power depletion worth. Going by the Degree of power attenuation, it can be assumed that many components can be used financially for 25 years or more.
Although not mandated, it has become sector practice to examine and accredit parts sold on the surface to IEC 61215 and IEC 61730. In recent years, some certified parts have also experienced high-quality problems throughout use, and also one can't assist yet ask: Why do elements licensed to IEC 61215 and IEC 61730 still have troubles? Answering this concern first requires a proper understanding of the duties of the IEC 61215 and IEC 61730 requirements.
The duty of the IEC 61215 requirement is clarified in the "Range as well as Objective" of IEC 61215-1:2016 "Photovoltaic modules for ground usage - Design qualification and finalization - Component 1: Checking requirements", the compliance with points required to be recognized:
1) The complying with summary is given in the typical "The purpose of this test series is to establish the electric and also thermal buildings of the module within one of the most affordable price and also time feasible and to show that the module has the ability to hold up against the outdoor climatic problems described in IEC 60721-2-1. Long-term use. The actual life span of elements that pass this examination depends on the layout of the elements and also the setting and conditions in which they are made use of." It can be merely recognized as: through basic testing, it is only confirmed that the element has the basic efficiency needed for long-lasting operation. It does not indicate that the component can be used for 25 years.
2) Only the general exterior environment kinds and their temperature level and moisture problems are offered in the criterion, and the history materials used as the basis for part design are not enough. For particular problems, the current IEC collection requirements take on a "spot" method, that is, to create unique examination standards for existing or arising needs or troubles, such as IEC TS 62804-1 "Solar Module Potential-Induced Destruction Test Technique No. 1" Components: Crystalline Silicon, IEC 61701 Salt Spray Corrosion Test for Photovoltaic Modules, IEC 62716 Ammonia Rust Test for Photovoltaic Modules.
3) On top of that, in the IEC 61215 typical to be more modified, the adhering to instructions are given: "Increased test problems are based upon actually observed failing settings. Different velocity variables can be picked according to the item design, and also the examination results must not be taken a prediction of the life span of the components, as well as not all depletion mechanisms, can be verified." According to the current interpretation of the criterion, blindly enhance the test problems for the components and their materials. The stamina or buildup, or the external insurance claim that the parts that pass the 3 times IEC common test can be used for thirty years, lack of basis.
Overall, the current IEC standards and national standards are total as well as not systematic enough. Also, there are still voids in meeting the requirements of element style, use, production as well as top quality confirmation.
1. Aspects influencing the life span of elements Different aspects affect the life span of parts to a greater or minimal degree and need the control of the entire process and all components. According to the analytical results, amongst the various variables impacting the service life of parts, the innovation is mature Degree, process quality assurance, and environmental flexibility are the vital variables that need to be managed.
1) Number 3 reveals the outcomes of the contrast test of the maximum power attenuation degree among the 6 power plants situated in different areas. Each power plant picks components from the same venture, which are put into use at the same time, as well as with various effectiveness degrees. Amongst them, the parts noted with "A" are the high-efficiency qualities in the same duration, and the components noted with "B" are the high-efficiency.
In the 6 comparison teams, the ordinary index of maximum power depletion of "A" type components is lower than that of "B" kind parts. According to experience, some "B" parts are still underdeveloped and secure in mass production.
2) Figure 4 shows that from 15 power plants situated in three climatic areas of my country, such as sub-humid warm, cozy temperature level, and cold temperature level, 15 kinds of parts were selected in each weather area, and also no less than 5 items of each component were selected without severe flaws elements, and also the outcomes of the contrast examination and also analysis of the maximum power depletion level.
Comparative, it can be seen that the optimal power depletion of the modules utilized in the cozy and sub-humid climate regions is not considerably different; the components used in the cold temperature region are dramatically different from the typical index as well as the extreme value index. Far better than the very first 2 types of ecological zones. This suggests that for some specific environmental problems, targeted layouts are required to improve the reliability of the elements.
3) Number 5 shows the results of the comparison examination and evaluation of the optimal power attenuation level by choosing 7 components without obvious flaws from 2 modules provided by different manufacturers used in the same power plant. The "attenuation index" in the number refers to the proportion of the module's determining maximum power attenuation rate to the ensured value of the same duration.
By comparison, it can be seen that the mean, as well as uniformity of the optimal power attenuation of the components of maker B, is substantially much better than that of the parts of manufacturer A, which mirrors that manufacturer A has troubles in-process quality assurance and also the uniformity of product top quality is poor.
It deserves to be pointed out that among the components tested, the parts created by a foreign firm used in a power plant have almost no depletion after 3 years of use, and the performance variance between the sample elements is very tiny, mirroring a high level of integrity.
2. Noticeable problems in the real use of components
Based upon the analysis of the existing examination data, the components throughout the operation period can be classified right into 4 fads in regards to optimal power depletion than the scenario. It can be approximately considered that: components with an average index less than 0.5 satisfy pattern 1 in Number 6; parts with a typical index of 0.5 to 1 comply with trend 2; parts with a typical index of 1 to 1.5 are diseased parts, tending to pattern 3; Components with an ordinary index greater than 1.5 have serious problems and tend to trend four.
In the initial analysis of the modules that tend to trend 3 as well as 4, the factors for the quick decay of the optimal power of the modules are mainly as complies with:
1) Given the environmental problems in certain climatic regions and serious climatic phenomena with high frequency, the layout or selection of elements is improperly taken into consideration;
1. Part flaws caused by engineering style or construction;
1. Component quality troubles are caused by poor component purchase and also process quality control;
3) Quality troubles brought on by some new parts and products used in batches that have not been fully validated.
Overall, regarding technical quality, there are 2 inequalities in the technical study of the solar industry. One is that the technological research study on integrity hangs back on the technological research on boosting the performance of specific devices; the other is that the study degree of system application modern technology drags that of equipment. End. In addition, it must be advised that in the past 2 years, way too much focus has been positioned on the reduction of preliminary setup expenses, and also not enough interest has been paid to the rise of later operation and also maintenance prices or the decrease of performance levels caused by insufficient integrity.
Among them, there are 19 types of parts with an operating time of much less than one year, and also the "mean index of optimal power attenuation" is 0.71; there are 32 kinds of components with an operation time of about 3 years, and the "mean index of maximum power depletion" is 0.71; There are 12 types of modules around 2010, and the "Mean Index of Maximum Power Depletion" is 0.72, which suggests that the average power depletion level of the components is substantially much better than the assured worth. Some accredited elements have also seasoned top quality problems throughout usage in recent years. One can't assist, however, ask: Why do elements accredited to IEC 61215 and IEC 61730 still have troubles? It can be comprehended as follows: with standard screening, it is only validated that the element has the basic performance needed for long-term operation. It does not mean that the component can be used for 25 years.
Aspects affecting the solution life of parts Different factors influence the service life of parts to a higher or lower level, as well as need the control of the whole procedure and all components. It can be roughly considered that: components with a typical index much less than 0.5 adjust to fad 1 in Figure 6; elements with a typical index of 0.5 to 1 conform to pattern 2; parts with an ordinary index of 1 to 1.5 are unhealthy parts, often tending to pattern 3; Elements with an ordinary index greater than 1.5 have serious issues and also often tend to trend 4.