Two years ago, GTM Research released a report that predicted the integrated smart and AC module market would reach 1 GW by 2020. Looking around at the market then, it seemed kind of impossible. The 2014 integrated market barely hit 73 MW, and it is supposed to increase 14 times to 1,000 MW in seven years?
Power optimizers (to make modules smart) and microinverters (to make modules AC) have been around and in use, but integrated modules with either option are harder to find.
Walking around the exhibit hall at Solar Power International 2017, it appears AC modules are making a comeback, and there might be some truth to that whole 1 GW by 2020 thing. Since Solar Power World gave the lowdown on smart modules in a previous article (read it here), we’ll now take a deeper look at the world of AC modules
What is an AC module?
In a traditional solar system, solar panels produce DC power, which gets fed to a nearby inverter and then converted into AC power for typical use. AC modules make that power conversion right at panel-level, so long cable runs to string or central inverters aren’t needed. Microinverters come pre-attached and pre-wired with the solar panels, so they’re called “AC modules.”
AC modules come with many installation benefits. Time spent installing is cut significantly when the inverter and module are positioned at the same time. Installers don’t have to attach electronics to rails and then attach panels. DC wire management is a thing of the past.
Since there’s a module-level switch to AC voltage, AC modules are safer to handle. These integrated modules are also NEC 2014 and 2017 rapid shutdown compliant from the get-go.
Logistics are easier, because the two products ship as one. Fewer components take up less space in warehouses. And if the module manufacturer offers a single warranty for the full system, performance is guaranteed.
What’s the deal with AC modules today?
To find AC modules, your best bet is to look at microinverter manufacturers and their partnerships. Five years ago, the two main microinverter companies trying AC modules were SolarBridge and Enphase. SolarBridge was acquired by module manufacturer SunPower in 2014, and SunPower now markets a full AC module within its SunPower Equinox residential system available through its dealer network. In addition to the AC module, the Equinox system has mounting, monitoring and one warranty. These AC modules have found success as part of a full system only sold by SunPower dealers, but on a limited (yet still large) scale.
Enphase has been in the AC module game for a while, but integrated modules with the company’s inverters hadn’t been seen for a few years. Installers were still purchasing Enphase microinverters and manually connecting them to solar panels, but an outright AC module was not being pushed.
Enphase now has two new AC module partnerships on the market—with LG and JinkoSolar—that promise a much better experience than the company’s efforts five or six years ago.
“Around 2011, we did enter into a couple partnerships for an early version of module. These were mechanical in nature; the ones now are electrical in nature,” said JD Dillon, vice president of product management and pricing at Enphase Energy. “The module was a microinverter clipped to the frame of a panel, and you still had to plug everything in, hook everything together. It sold almost as a kit. That’s why I call it mechanical—it was clipped and plugged as opposed to fully integrated.”
Enphase’s new IQ series of microinverters have been specifically developed for AC modules and now ship fully integrated with LG or JinkoSolar panels. Rather than its “mechanical” connection attempts with early AC module efforts, these new systems are “electrical” and offer easier plug-and-play options from Enphase.
The microinverter is pre-mounted and fully tested with the LG and JinkoSolar panels. The microinverter is backsheet attached and ships collapsed within the panel’s frame. When the module is ready to be installed, the microinverter is pulled down gently and snapped into place with 15 mm of airflow between the backsheet and the microinverter. This improved airflow helps with performance and reliability.
Modeling plans from SunPower, Enphase is interested in being part of an entire system that begins with an AC module.
“The IQ series [of microinverters for AC modules] represents an eventual link to energy independence,” Dillon said. “We’re going to be upward compatible from here on out. Our ultimate goal is to be almost a solar appliance on the roof for an energy-independent world. An inverter, a panel, the software, the energy management system and the battery—that’s a cohesive, self-sustaining system.”
LG and JinkoSolar are just the first partnerships Enphase has set up for AC modules. If the company increases access to AC module offerings, the U.S. industry just may hit 1 GW of integrated installations by 2020.