Knowledge Sharing

PID stands for Potential Induced Degradation which occurs when the modules are exposed to high negative voltage with respect to the ground. PID happens in ungrounded PV systems and is more prominent near modules towards the negative end of the string, exposed to negative potential with reference to ground.

The main causes of PID are:

Migration of positive ions from the glass plate through the EVA and ARC to the cell. The presence of these ions causes an effective shunt path across the cell and reduces the output.Buildup of the negative potential

Executive Summary

PVD conducted a diagnostics study of two solar plants of 5.75 MW each for a client in Rajasthan and Maharashtra and was successful in getting a warranty claim worth INR 1 Crore for the client. We would like to share the process that we followed for the benefit of our readers. 

The plants were 8 years old and had 41,060 modules of 280 Wp poly-crystalline technology. As a first step, we conducted a basic diagnostics study (On-field I-V curve measurement for sample strings and modules, thermal imaging of modules &

BoS of a solar PV plant constitutes all the components of a PV system other than the modules. These components makeup roughly 15-20% of solar purchasing and installation costs and account for the majority of maintenance requirements. It is through the balance-of-system components that we control cost, increase efficiency, and modernize solar PV systems. It has been observed in the industry that BoS care is sometimes ignored in comparison to the modules. We are sharing some of the similar cases in which owners and developers learned this in the hard

As the world broadens its portfolio of power options to meet growing energy demands and increasingly stringent environmental concerns, solar power is emerging as an attractive option. However, the current lockdown has taken a toll on the operations and maintenance activities of our solar power plants. This situation is more adverse for the rooftop plants located on the commercial and industrial locations because these power plants have also experienced several months of inactivity. Such prolonged isolation coupled with high summer temperatures can impact the health of the plant. In this

One of the most important factors while optimizing the cost of a solar power plant is Module Mounting Structure (MMS) which is a key ingredient in the successful running of a solar power plant. Most of the BoS components like transformers, inverter, cables, SCB, etc. are bought from the suppliers but the designing of modules mounting structures has to be done by an EPC and can prove fatal for the power plant if not done properly.

The design of modules mounting structures are typically of three types based on technology:

Fixed tilt
Seasonal

Electroluminescence (EL) is an electrical and optical phenomenon in which a material emits light in response to a passage of an electric current or to a strong electric field. Onsite EL Imaging is performed after evening twilight so that IR from the Sun does not affect IR luminescence from the module. This technology is used to test the solar modules for inherent defects like micro-crack, soldering defects, debris or even to detect an inactive string inside a solar module. EL Imaging is becoming more and more important for quality testing

Indian solar industry has grown tremendously over the last decade, a trend that is expected to continue in the coming years. India has become one of the cheapest producers of solar power worldwide. While this cost reduction was driven mainly by the falling module prices, increased competition and aggressive bidding had led many developers to cut down on their O&M budget. Lower O&M budgets can downgrade the sophistication of O&M practices. Here’s a list of 10 items that lean O&M teams should avoid ensuring best-in-class O&M with a limited budget.

Bifacial modules are those which produces solar power from both sides of the panel in contrast to the conventional mono-facial modules, which produces power from only one side where solar radiation is received.  In the case of Bi-facial, power is produced from both the sides of the panel using direct radiation falling on the module as well as indirect radiation coming through reflection from ground or diffusion. Fig 1 [1] below illustrates the working of the bi-facial module:

The power generation from the rear side highly depends upon the reflectivity of

In the earlier editions of this newsletter, we discussed the mechanism of potential induced degradation in poly-crystalline and thin-film modules and how it is impacting the performance of the existing solar power plants. In the current article, we will talk about the different component in cells and modules that could impact the PID susceptibility of solar modules in the plant. We will also discuss how we can test for PID susceptibility and what does “PID free” tag actually mean

Certain types of cells or modules may be more susceptible to PID

In continuation of our previous article on “Introduction to Potential Induced Degradation”, we have compiled research and data, to help our readers understand this mechanism in thin-film modules. In this article, we will also talk about some common performance issues faced by plants with thin film modules and the corrective measures that can be taken to improve performance from these plants.

Thin-film modules hit the solar PV market in India as the second generation of PV modules in 2010. Between the years 2011-2014, the total installed capacity of thin-film modules