Inverter Intel: Keep Older Units Performing At Their Peak With Data-Driven Analysis And Repair
Updated: Jul 9, 2020
By: Cliff Myers, Solar Support Chief Engineer & Co-Founder - July 2020
During the first half of the 2010s, a wave of solar growth planted inverters in systems across the U.S. around the world. Today, tens of thousands of these aging units are still chugging along—and can keep on going with the right kind of maintenance. Because the older plants they drive are under PPAs that can be up to four times richer than today’s agreements, they’re more than worth the effort.
If you’re an asset manager with a plant running older inverters, you’ll do whatever it takes to reduce downtime and recoup lost revenue when a unit fails. Fast recovery starts with knowing who to call—and the OEM may no longer be the most efficient or cost-effective option.
Solar Support cut its teeth during that early solar heyday. Because there were so many units out there, we saw and solved a massive number of faults. That knowledge puts us in a prime position to help operators diagnose and solve problems with vintage inverters.
Digging into the data
Central inverter data is readily available from the SCADA server—but the key is knowing what this data means and what to do with it. Our first step is to pull the SD memory card from the failing inverter and interpret the data fast—with a guaranteed 24-hour response time. Then we pinpoint problems with an accuracy that even OEMs can’t match. In the two-and-a-half years we’ve been in business, our analyses have been extraordinarily accurate, and we’ve yet to meet a problem we couldn't solve.
The big three
These classic central inverters tend to fail in predictable ways, with three issues rising to the top in job after job.
Stack failure. Call it the stack, the matrices, the drives, the IGBT—this DC-to-AC converter operates at the highest temperatures and under the most stress in the inverter. And the usual culprit is the capacitor. Built to run at a balmy 25 degrees C, capacitors in solar installations routinely face harsh extremes of heat and cold. The result is failure in three to six years instead of the advertised 12 to 15.
Current transducer failure. Another component that can’t take the heat, current transducers wear out over time and end up with temperature drift or failed transistors. Without an accurate current measurement, the inverter shuts down.
Breaker failure. One of the most dissed components in the central inverter universe, breakers have a tough job. As the unit’s only moving part, they’re expected to keep cycling all day, every day. In harsh environments, they simply fail faster than they should.
Crossed signals. Lost revenue.
Taking the wrong steps to fix an aging inverter failure can add up to real losses. We worked with a client that finally called us after 40 days of downtime. They’d paid the OEM to try to figure out the problem, replaced $40,000 in parts and lost $12,000 in revenue.
We analyzed their data, diagnosed the problem and responded in three hours with the exact solution we could have found 40 days earlier. The fix was simple and didn’t require a single new part. That client went on to hire us to analyze 200 data sets over the next year. Click here to request data analysis for your inverters.
This graph shows the impact of temperatures revealing dormant faults from the winter
Going above and beyond
We help operators get their inverters back online and their plants operating at peak performance. But we go farther by providing the end user with as much knowledge as we can.
When we analyze a data set, we don’t just stop at the solution to the problem at hand. We check out everything else and report on the inverter’s overall status. This gives the operator a heads-up about issues to watch for—and even spare parts they may want to keep in inventory.
If the repair calls for parts, we offer on-the-spot estimates and competitive pricing. We get you what you need quickly so your operation can get back up and running fast. Check our specialty components store for details on our stacks replacement program that delivers new IGBTs in 48 hours.
Like a Venus flytrap
Solar Support is voracious when it comes to knowledge. Unlike competitors with a narrow focus on a particular product, we continue to build out and deepen our knowledge base. We haven’t stopped at one product, and we don’t intend to.
We believe great information should never go to waste. So when we learn something, we capture it, hold on to it and share it. That’s why we continually publish articles, troubleshooting tips and procedures for clients and the broader industry. We’ve even built an open-source solutions portal where technicians can look up fault codes and diagnostics measures to perform their own repairs on the fly.
We’re truly striving to equip end users with the knowledge and skill to take care of these stalwart power plants. No one works harder to help you handle your business than we do.
About the Author
Cliff Myers, a Navy Veteran, drives restoration excellence, bringing his expertise in solar systems fault resolution and performance optimization to Solar Support. With over 14 years combined experience in utility PV technology and power conversion systems, Cliff steers the company’s engineering division and plant restoration strategies. Cliff graduated Magna Cum Laude from Arizona State University with a Bachelor of Science in Electrical Engineering. Cliff is also the co-founder of Solar Support.