Many commercial and utility solar projects that were installed at the start of the solar construction boom will celebrate their 10th birthday around 2020. But instead of indulging in something, this milestone is a nuisance for many project owners, as the string inverters are based on these systems are approaching their average lifespan of 15 years.
In a new report, Wood Mackenzie estimated that approximately 4.2 GWDC of global solar systems will fail prematurely in 2020, with the annual total increasing to 36 GWDC in 2025.
The big question is, are project owners adequately prepared for the O&M required to handle an influx of expired inverters between now and 2025?
The surveillance problem
In the study, Wood Mackenzie found that the basic scope of solar O&M contracts covered very few basic maintenance activities.
Silvia Blumenschein-Schütz, managing director of the solar monitoring provider Solar-Log, found a similar topic in discussions with project owners. She recalls an EPC that came up to her at a solar trade show in early 2020 and said it was considering adding a surveillance to its portfolio of around 10,000 projects. She mentioned that it would be helpful to add monitoring hardware to the inverters as well to collect more complete performance data, and he reluctantly thought of having to visit each site to install them.
“I said, ‘Don’t you go out once a year? ‘And he looked at me and said: “I don’t see any need for it,” said Blumenschein-Schütz. “If you’re just talking about the typical residential, commercial, and industrial sectors, we’d all be surprised to see how many locations are not yet properly monitored. People don’t realize that they are losing a lot of money and how easy it is to get back into this business for long term money. “
There are many options in the field of solar monitoring. The technology is evolving to make project owners more aware of errors or maintenance requirements. But many wealthy owners still don’t invest in them.
Anne Nelson, Solar-Log’s chief marketing officer, said more training is needed to show project owners the importance of monitoring.
“O&M and the idea of selling services are a relatively new topic when we talk about the solar market,” said Nelson.
Many first generation solar projects have been installed without supervision, so project owners are unlikely to know if these aging inverters are working properly.
“When we talk about the amount of money that would be lost, especially if an on-site inverter dies and goes completely undetected, even a small waste means a huge financial loss. However, if the inverter dies completely, a lot of money will be lost. Nelson said. “If a lot of system owners knew this, they would be quite willing to invest in releasing a service provider and adding monitoring so that they can identify and protect this investment, which is said to last 20-25 years, much later inverter life. “
Most new inverters have built-in monitoring options. However, if sites have multiple brands of inverters due to swaps over the years, monitoring is best done by a neutral third-party system.
“I really believe that it is so important to have a neutral, inverter-independent monitoring platform because when it comes to older systems, when you have to replace components that are not the brand that is already on site, how do you monitor it? unless you have a neutral system that can connect all the different components, regardless of the make or model? “Said Nelson.
Logistic considerations for servicing the inverter
Another problem for project owners and O&M companies is that not all inverters fail at the same time and cost more money for multiple one-time truck rolls to locations.
“You will not be able to be very efficient at this because they are all a series of unique pieces and fail at different times,” said Derek Chase, CEO of O&M provider SunSystem Technology. “If you are able to put all of this together and then do a bulk purchase and plan them all out on smooth routes, you can really cut the cost of all of this. But nobody will be that proactive – they will just wait for one to go and another to go. Somehow someone here has to see the bigger picture and try to put all of these things together. “
SunSystem is working with Palmetto Solar on the development of such an aggregation for the segment of solar systems for private households. The O&M company was struggling to organize the sales and financing logistics for each individual homeowner who had inverters to repair. SunSystem decided to partner with financier Palmetto Solar to bring together all of the individual, non-leased PPA customers and sell them new inverters, service and maintenance as part of Palmetto’s existing financing plan. That way, residents don’t look for an amazing bill for an inverter replacement.
However, servicing inverters for the larger solar market is more complicated. Chase believes many asset owners still view O&M as an afterthought. He also believes that more inspections should be done to ensure the systems are safe throughout their life.
“There isn’t even a standard and there is no enforcement of it. I think that makes it an afterthought. [Owners think]”Hey, whatever if something happens, we’re going to find out,” not “If I don’t do this, an inspector could show up and shut down our facility, and that would be bad news,” Chase said.
Readiness of the inverter manufacturer
Chase also has concerns about whether string inverter manufacturers are willing to handle the influx of inverters nearing 15 years of service life that need servicing or replacement.
When SunSystem needs to fix an inverter, Chase first calls the manufacturer to verify that the device is indeed dead and that the warranty is no longer valid. Then he sees if there is any financial disruption if the unit is replaced with the company’s product instead of changing brands.
Unfortunately, many inverter companies from the early 2010s are no longer in business. The inverter market has always been volatile, with high profile company exits and acquisitions happening almost every year. Even if the original manufacturer is still in business, 10 year old inverters most likely no longer have a warranty.
SunSystem’s 170-strong team has determined that it can take up to an hour to call a manufacturer to diagnose certain inverter problems.
“Multiply that by 170 technicians plus whatever other technicians from different companies are out there, the amount of waiting time is insane from a labor cost standpoint,” said Chase.
He believes that inverter manufacturers should either expand their customer service staff or offer digital solutions that allow technicians to submit requests for authorization of returns through an app or a similar streamlined process.
String inverter manufacturer CPS America has heard the customer service issues from O&M technicians and is working on solutions to streamline the process. The company routes calls with RingCentral and aims to have a human representative answer the call 90% of the time.
CPS also started a training program for authorized service providers in early 2020 to help O&M technicians learn details about the inverter line so they can troubleshoot themselves on site. The training is virtual and is also offered at the company’s Texas headquarters. This allows O&M technicians to build relationships with CPS employees.
“The inverter companies are squashed and are under pressure. Not every inverter company has enough resources to answer the phone anytime, ”said Ed Heacox, general manager of CPS America. “One way to ensure that a good service is available is to anticipate it and establish relationships in the region.”
CPS has stocks of reconditioned replacement inverter models that O&M technicians can use to replace failed units. But when 2025 approaches and old units reach the end of their useful life en masse, this supply will eventually run out.
“In addition to verifying the willingness to support the field with suppliers like us, another diligence some companies take is to consider what a reasonable retrofit of an old site on a modern inverter is.” Heacox said.
He assumes that retrofitting will become more and more popular as the original inverter fleet gets older, regardless of whether old central inverters are replaced by strings, 600 V inverters are replaced by 1,000 V inverters or higher, or other configurations.
According to SunSystem’s Chase, the most cost-effective solution when a string inverter fails is to swap with another string inverter. However, systems can have a longer lifespan if the old string inverters are swapped out for new technologies such as string inverters with optimizers or even microinverters. It can also be a good time to add space to projects.
“One thing I always tell everyone – when you get a new inverter [or] Make any investments – your first few dollars will have to go into a surveillance system, ”Chase said.
Recognizing that an inverter is not working at all is critical as early inverters are nearing their 15 year lifespan.
“We are 10 years old now. It’s a perfect time to go back to your original customer base and say, “Hey, you might be losing money, let’s take a look at the system. Let’s put in proper professional surveillance so we can spot these issues, ”said Nelson.