Jinko Solar recognized as a Top Performer in DNV GL Scorecard 2018
JinkoSolar Holding Co., Ltd, a global leader in the solar PV industry, has been recognized by DNV GL as the “Top Performer” among global PV module manufacturers. This is the fourth time that Jinko Solar has been awarded. DNV GL is a global quality assurance and risk management company which provides classification, technical assurance, software and independent expert advisory services to the maritime, oil & gas, power and renewables industries.
The DNV GL Scorecard: What does it measure and test for?
The Scorecard itself is based on a separate set of measures known as the Production Qualification Program (PQP). The PQP is designed to give solar buyers and power plant investor’s reliable data on solar product quality and durability, so that they can make informed decisions on which suppliers to work with. Here are a few of its specific tests and metrics it includes:
a) Thermal cycling
Solar module materials routinely expand and contract based on changes in environmental temperature and irradiance. Such changes can adversely affect performance by introducing additional stress on specific components. A thermal cycling test will subject modules to extreme temperatures and measure the resulting degree of power degradation. IEC 61215 requires MAX 5% power degradation after only 200 cycles which may be estimated to represent roughly 5 years of field exposure depending on the environment. DNV GL’s PQP sequence has been extended to 800 cycles in 2018 and Top Performers show less than 2% power degradation after the test The median result in the 2018 test was 1.6 percent, with the worst performed coming in at 8.8 percent.
b) Damp heat
In addition to temperature, PV panels are also affected by humidity. The PV damp heat test gauges the long-term impact of both conditions on modules. It is designed to measure panel response EEN in temperate climates that do not feature extreme temperatures and excessive humidity levels. In an IEC 61215 Damp Heat test, modules are held at a constant temperature of 85°C and a relative humidity of 85% for 1,000 hours (approximately 42 days). This moisture ingress stresses the module’s adhered interfaces. DNV GL has performed hundreds of Damp Heat tests at various durations, assessing module resilience as a function of these
durations. DNV GL has found that 2,000 hours, as used in the PQP, are effective at differentiating top performance versus average performance. Also in this case Top Performers show less than 2% power degradation after the PQP test, while IEC max degradation is set at 5%.
c) Dynamic mechanical load
DML - dynamic mechanical load test evaluates solar module resilience in the face of wind and snow., it tests the modules real-world performance , utilizing a test sequence of mechanical stress to cause cell cracks (1,000 cycles at ±1,000 Pa) followed by thermal stress (50 cycles of thermal cycling) to cause crack propagation followed by freezing moisture stress (10 cycles of humidity freeze), which causes cell cracks to impact power output while modules are in the mounting positions as per the manufacturer’s specifications. The results of the DML testing showed some of the least variance of all tests performed with degradation up to 3%while Top Performers showed power degradation lower than 2%.
d) Potential induced degradation
The potential induced degradation (PID) test is designed for ungrounded and high-voltage systems, which have become more commonly deployed over time. PID is the result of biases in internal PV circuits that lead to increased leakage currents. Modules are tested by being exposed to voltage biases equal to their respective voltage ratings under 85°C and 85% relative humidity conditions for two sessions of 96 hours. According to IEC requirements, 5% MAX power degradation should not be exceeded even after one single session. PID tests results were varied, from a median of 1.4 % to a low of 7.4 %.The threshold to qualify as Top Performer is <2% degradation for the PID test in the PQP sequence.
e) Historical Scorecard
A new feature in this year’s Scorecard is the introduction of a “Historical Scorecard.” This recognizes manufacturers that have been consistently ranked among the Top Performers over the last four previous Scorecard editions, and highlights those manufacturers who are new to the market, newly participating in the PQP and Scorecard, or newly named Top Performer in 2018.