Microinverters are a common component in residential solar projects that are built to handle the wattage of smaller-scale PV arrays. But like solar modules, microinverters are increasing in capacity and can handle larger electrical loads. For example, inverter manufacturer APsystems’ new QT2 microinverter can invert energy from four solar panels at a time, unlike previous models that were installed on single modules. Jason Higginson, head of marketing for APsystems USA, is here to discuss this new breakthrough and the subsequent trend of microinverters entering the commercial and industrial solar market.
Below is an excerpt of APsystems’ Solar Spotlight podcast with Solar Power World, but be sure to listen to the full episode here or on your favorite podcast app.
Why are we seeing this trend of microinverters shifting into C&I with what has traditionally been primarily a residential solar product?
We see the shift happening because many of the hang ups with microinverters in C&I applications, especially three-phase applications, no longer exist. So even though our new line of three-phase microinverters, QT2, is ideal for C&I projects, there are a lot of myths or preconceptions that still exist around using microinverters outside of residential solar.
What can you tell me about the new QT2 microinverter?
The QT2 is a native three-phase microinverter that serves four PV modules simultaneously. It can be paired with four PV modules up to 550 W to 575 W — that is probably the sweet spot — but it can accommodate even higher wattage modules without negatively impacting the inverter. So, it comes in 208- and 480-V models that can be used for Y delta and even 240 delta high-leg configurations. So, really, any new or existing commercial and industrial buildings can use this microinverter.
What sort of myths exist around the use of microinverters in the commercial and industrial solar space?
Microinverters go back a ways in this industry, and traditionally they have had a lot of success in residential solar. Unfortunately, if you do something well, long enough, it can sometimes be perceived that that’s all you do. It would kind of be like me telling people they can use their barbecue to cook a pizza — which I’ve done by the way, it actually wasn’t too bad. We specifically designed the QT2 for C&I applications, and we were immediately met with resistance from the industry. Without looking at specs or pricing, customers would say microinverters are too expensive, they’re not powerful enough. None of these are true with the QT2.
How are microinverters suddenly more competitive in C&I?
So, historically, microinverters compared with popular C&I inverter, the string inverter, microinverters were twice the price, sometimes more, and microinverters have significantly cut down on cost over the years, APsystems microinverters in particular. When you look at the cost-per-watt of output, it’s a dramatic change in pricing over the years, especially considering we’ve designed it to serve four PV modules, and it does not cost the same as four individual microinverters. Now compare that to string inverters which now must have a rapid shutdown system for rooftop applications, but it now adds an additional 50 to 70% of the inverter cost to the system pricing.
Is there anything else we should know about the QT2?
Yes, I also want to say that another one of those big myths is shading and I just tell everybody that shading can come in many forms. So, we see quite often dust, dirt, bird droppings, snow, in addition to clouds and rain that happens all the time. Microinverters performed better under all these conditions compared with standalone string inverters.
This podcast is sponsored by APsystems
Mark Smyth says
HI Billy Ludt,
I read the brief summary of the AP micro inverter system. I have had limited experience with the Enphase units and found there is frequent module failure and the conversion efficiency is below the ratings. I have a few neighbours with micro inverters and they also have failure issues (not only with Enphase) as well as commissioning difficulties. Comparing to string units based on cost, even with rapid shutdown, the ongoing replacement cost of the micro inverters and the poor DC- AC conversion is not favourable compared to the experience with install and forget experience I have had with string inverters. Typically the string inverters I have used will (slightly)exceed the output rating of the unit…