Light induced degradation of solar cells made from high performance multi wafers kai petter, christian fahrland, yvonne ludwig, friederike. Over time, we made griddler the platform to design solar cells, calculate solar cell efficiency, quantify limiting factors, store published cell parameters gathered from all over the world, and predict the rooms for improvement by employing different design changes. In gridconnected pv systems, solar panels are typically connected in series to build up the voltage output while the module frames are grounded for safety. Potential induced degradation pid is one of the degradation behaviour of photovoltaic pv modules exposed outdoors. Light induced degradation lid can lead to significant power degradation. When pid occurs, the aforementioned process is disrupted by the presence of electrical charge carriers, mainly the sodium ions of the glass which moved to the solar cell and pn junction. As photovoltaics are connected both in series and in parallel, the panels are. Potential induced degradation test method solar pv test. Potential induced degradation what is potential induced degradation. Potential differences between in a string connected pvcells and the ground potential cause a leakage current as early as 1978 and in the nineties leakage current driven electrochemical corrosion and polarization effects of crystalline and thinfilm cells in modules were reported, and a minimum. Potential induced degradation of solar cells and panels.
Effect of humidity and temperature on the potential. In solar modules connected in series, the same current flows through all of them, so the voltage increases with each panel in the chain. Sodium outdiffusion from stacking faults as root cause for the. What is pid and how can you reduce solar power loss. Potential induced degradation of solar cells and panels ieee xplore. Wo2012168249a3 method for measuring potential induced. In this paper, we show the typical timedependent behavior of solar cell parameters during light soaking, and the effect of thermal annealing. For q cells solar cells and modules, potential induced degradation pid doesnt exist. Pingel and others published potential induced degradation of solar cells and panels, ieee photovoltaic specialists conference, honolulu find, read and cite all the. Underperformance is the major result of potential induced degradation pid to the solar panels that you have invested on. In the existing models the pid is due to the high voltages forcing the sodium ions to diffuse from glass through encapsulate and. It is widely considered that pid is closely related with the manufacture and application period of solar modules. Pdf impact of potential induced degradation on solar pv.
According to the invention, a conductive plastic material is pressed upon the upper or lower face, in particular the front face of the relevant solar cell, and a direct current voltage greater than 50 v is applied between the plastic material and the relevant solar cell. This paper is focusing on potential induced degradation pid of wafer based standard ptype silicon technology once exposed to external potentials in the field. Experimental analysis of the potential induced degradation effect. Standard silicon solar cells with a front side emitter may suffer from pid through massive shunting pids under high voltage stress conditions. The term potential induced degradation pid was first introduced in the english language in a published study by s. Potentialinduced degradation at interdigitated back contact.
Winklerpotential induced degradation of solar cells and panels. Eu pvsec proceedings potential induced degradation of solar. A pv module is an assembly of photovoltaic cells mounted in a frame work. Nov 28, 20 in recent years, news about severe quality issues with pv panels have become more and more in quantity. Potential induced degradation pid is wellknown and feared by solar panel manufacturers the world over. Origin of na causing potentialinduced degradation for p. Pdf potential induced degradation of solar cells and. Pid potential induced degradation pids pid related to solar cell shunting pidp pid related to a degradation of the front side passivation layer of a solar cell ffe front floating emitter ibc interdigitated back contact 2. Chemical instability refers to light induced degradation in amorphous silicon solar cells or to the limited number of redox cycles for electrolytes in novel solar cells. As photovoltaics are connected both in series and in parallel, the panels are exposed to high potentials compared to the ground. To that end, organic solar cells are manufactured and are then. Warranties typically guarantee approximately 97% of the nameplate rating during the first year followed by an annual 0. Pdf initial degradation of industrial silicon solar.
Definition pid or potential induced degradation is a problem that occurs on many photovoltaic panels when they are exposed to a negative voltage to ground. Our modules are down 40%, we think it is potentialinduced degradation. They have passed stringent testing for australias arid and equally inclement weather the whole range of has passed the 96hour potential induced degradation pid resistance test as required by iec62804 standards. Some module power degradation is expected, so a degradation factor is usually built into solar assets energy yield and financial models as well as manufacturers warranty terms. In electrical engineering, voltage is defined as the difference between electric potentials.
It results from the leakage of electrical current from the cell of a solar pv module to the panel frame. Potential induced degradation pid can be understood as a designation for aging effects which arise due to. Over the last decade, potential induced degradation pid has been proven to be one of the major and most frequently occurring reliability issues of crystalline silicon photovoltaic pv cells and modules. We compared degradation of solar cell parameters with that of the minoritycarrier lifetime measured on sister wafers of the solar cells. Most solar power is produced using csi panels, meaning over 50% of solar capacity is at risk of pid loses. The increased usage of transformerless inverters on u. Ideally, the solar panels are expected to last and display its optimum performance for 20 years. Described in simple terms, pid is a drop in output caused by high voltage, high humidity and high temperature environments. Both of these modules are framed multicrystalline mcsi with glasspolymeric backsheet construction. To that end, organic solar cells are manufactured and are then undergone a series of voltagedependent degradation and timedependent voltage degradation tests. All q cells products come with anti pid technology since 2012. Sunpower stands behind its panels with its industryleading complete. Impact of potential induced degradation on solar pv module. Pdf since solar energy generation is getting more and more important.
Pdf initial degradation of industrial silicon solar cells. Although some types of pid are reversible, others are not, and those are therefore a permanent problem for the. Potential induced degradation of solar cells and panels j. At first, the influence of humidity and temperature on the potential. Recovery methods for modules affected by potential induced degradation pid. Understanding lightinduced degradation of csi solar cells. What is pid potential induced dagradation explained. This paper reports an extensive analysis of the potential induced degradation pid of ntype bifacial solar cells. Potentialinduced degradation pid of photovoltaic panels. Potentialinduced degradation pid is characterized by the power loss of solar modules. Experimental to investigate how our ntype ibc cells with ffe behave when biased at high voltages against the ground we.
For solar cells and solar modules from q cells, potential induced degradation pid doesnt exist. In order to clarify the degradation mechanism, numerical calculations were performed in the case of thunderstroke, based on the maxwells electromagnetic equations. Potential induced degradation pid is a failure mode in solar cells caused by voltage stress on the pid module. Besides the precondition of having a pid sensitive cell they also showed ways to stop or minimize pid on panel. Simulation suggests origin of potential induced degradation. Micro structural root cause analysis of potential induced. Potential induced degradation pid refers to the phenomenon of power output losses from a solar pv module.
Test setups are presented for simulation of the pid in the lab and the influence of cell properties on pid is demonstrated in order to reveal the cell being the precondition for the pid. The analysis is based on combined electrical characterization, electroluminescence and external quantum efficiency measurements, carried out on solar cells submitted to high pid stresses. Initial degradation of industrial silicon solar cells in solar panels abstractsummary. Information about the lg neons solar technology, allowing the additional efficency download. Potential induced degradation, reliability, inversion layer, solar cells, theoretical model. Potential induced degradation solar modules manufacturer. Pid is an undesirable effect on of some solar modules. The factors that can cause pid include voltage, heat and humidity and most solar modules are exposed to the combination of these factors during their working life. Potentialinduced degradation in photovoltaic modules based. With its diverse international manufacturing facilities in south korea, malaysia and china, hanwha q cells is in a.
Potential induced degradation also called pid is a potential induced performance degradation in. Photovoltaic solar panels absorb sunlight as a source of energy to generate direct current electricity. There are increasingly often reports about mysterious output yield losses which are linked to potential induced degradation pid. Pid can lead to a performance loss of 20% or more, even in the first few months. Pid impacts the ions of a solar cell and results in the degradation of the output of that cell. However, until now the degradation mechanism correlated with hvs is not covered by the standard test procedures listed in iec 61215 3. Potential induced degradation pid has recently been identified as one of the most important degradation mechanisms for silicon solar cells. The issue of potential induced degradation pid has gained more concerns due to causing the catastrophic failures in photovoltaic pv modules. Potentialinduced degradation pid is a potentialinduced performance degradation in crystalline photovoltaic modules, caused by socalled stray currents.
Pid causes an accelerated degradation in performance which expands exponentially. Apr 08, 2015 potential induced degradation on pv panels. Potentialinduced degradation for encapsulated ntype ibc. Crosssection of a backcontact solar cell with ntype passivation capped with a silicon dioxide, silicon nitride arc. This potential degradation mechanism is not monitored by the typical pv tests listed in leg 61215 2. Pid happens when different components in the same system are at different voltage potentials such as the frame and the solar cell. Sunpower performance panels are the most deployed shingled solar panel in the world. This paper is focusing on potential induced degradation pid of wafer based standard ptype. Faq commercial solar what is pid potential induced degradation. How is potential induced degradation pid test 96h performed. In 2007, pid was reported in a number of solar panels from evergreen solar photon 12008 and 8 2008. Sep 03, 2015 potential induced degradation pid is a phenomena that has only recently become a concern in the photovoltaic industry. But what is a panels potential to the ground exactly.
Potentialinduced degradation pid is a potential induced performance degradation in crystalline photovoltaic modules, caused by socalled stray currents. Potential induced degradation affects many solar power arrays by reducing panel performance more and more over time. In the first case potential induced degradation pid conducted by high voltages, and the other light induced degradation lid conducted by sunlight real or simulated the. The scope of this paper is to analyze experimentally the potential induced degradation pid in organic solar cells. Potential induced degradation, either reversible or not, is present in all types of csi crystalline silicon pv cells and was first described back in the 1970s 2. A particular focus of his work is on assessment and physical understanding of potential induced degradation of silicon solar cells.
Potential induced degradation in conventional ptype siliconbased photovoltaic solar cell modules is described as a failure mechanism involving positive ion migration, understood to be primarily. Enhancement for potentialinduced degradation resistance of. Effects of diffusion process on potential induced degradation. Pid potential induced degradation is a phenomenon that negatively affects the cells of pv modules. His work area comprises electrical characterization, microstructural diagnostics and elemental analyses at silicon and thin films for photovoltaic applications. In this paper we present potentialinduced degradation pid and uvinduced degradation uvid. Elimination of potentialinduced degradation for crystalline. It is a process which occurs only a few years after installation. Then high positive voltage is applied at upper electrode voltage equivalent to pid in the module while heating the bottom ground electrode. Jun 05, 2017 although crystalline solar power panels are often sold with 25 to 30year lifespan guarantees, those 30yearold modules wont be performing as well as they did on day 1. Pid was first observed for sunpower modules with rearjunction ntype solar cells. Potential induced degradation of ntype bifacial silicon. This potential degradation mechanism is not monitored by the typical pv tests listed in iec 61215 2.
Since solar energy generation is getting more and more important worldwide pv systems and solar parks are becoming larger consisting of an increasing. Physics of potentialinduced degradation in bifacial p. It was introduced as a degradation mode resulting from voltage potential between the cells in the photovoltaic module and ground. The cause of the harmful leakage currents, besides the structure of the solar cell, is the voltage of the individual photovoltaic pv modules to the ground. Recovery methods for modules affected by potential induced. The potential induced degradation is one of the biggest problems for practical use of solar cell panels. For the test, a setup of modulelike layer stack of solar cells, polymer foil and glass is placed between two metal electrodes. Potential induced degradation pid is characterized by the power loss of solar modules under high voltage stress across the module layer stack between framingglass surface and solar cells. One of the approaches to diminish pid is to modify the antireflection coating arc layer upon the front surface of crystalline silicon solar cells. Potential induced degradation can lead to a performance loss of 20 % or more, even in the first few months. Pid is a phenomenon that output power is greatly deteriorated in a short period, which is different from aging degradation. Depending on the technology different types of potential induced degradation pid occur. Elimination of potential induced degradation for crystalline silicon solar cells abstract potential induced degradation pid is an extremely serious photovoltaic pv durability issue significantly observed in crystalline silicon pv modules due to its rapid power degradation, particularly when compared to other pv degradation modes. Potential induced degradation pid is often considered as the most serious degradation threat to a solar plant today.
Depending on the technology different types of potential induced degradation pio occur. This degradation mechanism is called potential induced degradation pid9. Perovskite solar cells are found to be exceptionally susceptible to potential. Mar 04, 2018 i take a look at the potential induced degradation pid and galvanic corrosion occurring between my tenesol solar panels and wellearthed aluminum solar mount. However, in only 2 to 3 years time, potential induced degradation happens and solar panel deficit takes place faster. The invention relates to a method for measuring the potential induced degradation pid of at least one solar cell. Pid is caused by leakage current flowing between al frame and cell. A photovoltaic pv module is a packaged, connected assembly of photovoltaic solar cells available in different voltages and wattages. Potential induced degradation of photovoltaic modules.
Experimental analysis of the potential induced degradation. Here, we focus on the modification of arc films to realize pidfree stepbystep through three. Eu pvsec proceedings potential induced degradation of. Often manufacturers promise pid free solar cells but still this solar degradation is observed in the field. Berghold, potential induced degradation of solar cells and panels, in proc. Effects of diffusion process on potential induced degradation of. Performance declines as solar cells experience degradation due to unavoidable circumstances like uv exposure and weather cycles. A mechanism of potential induced degradation pid delay effect by ultraviolet uv light irradiation during pid test for ptype crystalline silicon csi solar cells was proposed in this work. Introduction of a novel test approach and explanation 835 in this paper, a method to test the resistance against pid on the solarcell level close to. Photovoltaic modules constitute the photovoltaic array of a photovoltaic system that generates and supplies solar. Pdf potential induced degradation of solar cells and panels.