The SolarEdge power optimiser is connected by installers to each panel or embedded by panel manufacturers, replacing the traditional solar junction box. Therefore, it must be as reliable as the panel itself with the ability to withstand the same environmental conditions to which the panel is exposed.
The essence of the SolarEdge reliability strategy is a physics-based multi-level method of failure point identification. Providing a warranty for a proven 25 year system operational lifetime was enabled through a combination of reliability-oriented design rules. With a selection of top-tier suppliers and acceptance testing of their components, which were manufactured in well-controlled environments, accelerated lifetime testing of the system (and its components) was conducted up to the wear-out point in order to determine when the product will fail, at what rate and by which failure mechanisms.
The SolarEdge multi-level reliability plan involves Design Analysis & Qualification by in-house and external experts, sub-system testing by Accelerated Life Testing (ALT) of critical components, and integrative testing of design prototypes (via HALT) and large sample groups.
As part of these efforts, tens of thousands of components have been evaluated in accelerated life chambers (burn-in, thermal cycling, humidity and so forth) as well as hundreds of products in field tests and stress tests. These tests have run for the equivalent of over 100 years (well over the expected life of photovoltaic systems). The lessons learned are invaluable and as a result, SolarEdge produces systems with unsurpassed reliability.
In order to verify that each SolarEdge product that leaves manufacturing plants conforms to our high reliability and quality standards, each component, sub-assembly, and final product are tested multiple times during production. These tests include: Automatic Optical Inspection, In-Circuit Testing, Board- and Component-Level Functional Testing, Safety Testing and Integrative Stress Testing. These rigorous screening and testing procedures, which are completed for 100% of the products we make, enable us to guarantee that SolarEdge products work as expected for the entire product lifetime.
A key element of our reliability strategy – and a significant differentiator relative to our competitors – is use of proprietary application specific ICs (ASIC) in our products. The best way to improve the reliability of electrical circuits is to reduce the number of components in it – this is done in SolarEdge products by replacing a large number of discrete components with a single ASIC designed specifically for the task at hand. The ASIC itself is manufactured with a fabrication process used for automotive-grade electronics (so operating temperatures are well within spec), and according to proprietary design rules specifically defined to allow for the long 25 year lifetime of the ASICs. Extensive analysis and testing has been done to assure the ASIC packaging is robust enough to handle the mechanical and electro-chemical stresses experienced over 25 years of daily thermal cycling.