NED University Has Developed A PV Testing Lab In Collaboration With PV Lab Pakistan (Bahawalpur) Under ASURE Centre.
ASURE Centre envisages to essentially cover multifaceted aspects related to alternate energy including testing, certification, training and research aspects on a broader scale and taking up of specific projects of smaller size benefitting a larger populace. On the broader scale the areas which could be taken up are listed as:
- To provide testing facility related to renewable energy equipment.
- To issue certificates and compliance report to the consignee.
- To create awareness session related to renewable energy to the local industries and residential consumer.
- Act as a long-term node to ensure the continuity of efforts on sustainable basis.
- To bridge the gap between academia and industry through research, consultation and providing customized smart energy solutions.
PV Testing Lab:
NED University has developed a PV testing LAB in collaboration with PV Lab Pakistan (Bahawalpur) under ASURE Centre. PV testing lab NED UET is a specialized test lab with focus on Quality Assurance and risk evaluation for PV modules. NED University has provided a space in Automotive Engineering Department. This lab is providing the testing facility to industry, commercial consumers, and government institutions. The aim of the testing facility is to build the confidence of the consumer that the reliable and energy efficient equipment is reaching to the market through standard compliance checking. Following tests are being performed on PV modules in the PV Lab. The details of individual tests are as follows1:
Power at STC (Standard Test Conditions)
Panel manufacturer claims maximum power output at standard testing conditions (STC). This number is a baseline for design of all solar farms. PV Lab operates a Class AAA sun simulator for conducting all its power tests. Solar simulators are classified in accordance with IEC 60904-9. Low level of uncertainty is only possible when Class AAA simulator is used. This test is crucial to draw solid conclusion and serves to validate modules performance as claimed by the manufacturer.
The test measures insulation resistance between the inner circuit and a water bath module is placed during testing. This test is relevant from a safety viewpoint.
Hot Spot Test (HS)
A thermographic camera is used to capture thermal images of a module. These images can reveal defects at soldering points, inactive regions in cells and formation of Hot Spots due to defective bypass diodes which can lead to irreversible damage to the module.
Electroluminescence is a diagnostic process in which a camera capable of detecting near-infrared light is used to take image of a module. This test is used for quality assurance during the manufacturing, transportation and rough installation processes of the modules to find micro-cracks. These tiny cracks in the cells can lead to electrical insulation across entire segments of the panel and these cracks are among the greatest risks for PV.
Potential Induced Degradation (PID)
PID or the voltage dependent ageing of photovoltaic modules, is a type of power degradation that generally appears on the negative side of the module string and can affect almost any type of photovoltaic module. Power loss from PID effect must be minimum and a power loss of 5% should not be exceeded in measurements before and after this period.
This test aims to measure the adhesion of the bedding material (generally EVA) to glass. The peel-off test is valuable, because a peel-off force that is too low can indicate either that the production process was carried out with non-optimal parameters, or that materials past their expiry date have been used.
The EVA cross-linking test determines what percentage of the transparent bedding material can be released using a solvent. The remaining portion is then termed the crosslinking level. If the level of cross-linking is too low, it can be an indicator of an increased risk of delamination, which can ultimately lead to failure of the module.
Need for Quality Assurance (QA)
We regularly find that PV modules have poor readings in the test laboratory or during inspections of incoming goods It is a common mistake to purchase modules on the basis of a data sheet or performance guarantee from the manufacturer. The only guarantee of receiving modules of an acceptable quality is to have detailed technical specifications including all the testing processes and corresponding pass/fail criteria. A considerably larger problem can arise when trying to claim for product defects that only become apparent after a period of usage. Considering this, it is vital to define testing requirements and their pass/fail criteria upfront in the purchase contract.