Over the past few years, solar modules have grown larger and more powerful. Installers must pair the latest cutting-edge panels with high-power inverters to ensure they’re getting as much energy as possible out of their systems.
Here are three manufacturers making inverters specifically tailored to high-power and bifacial modules. More companies are sure to bring updated product to the market sooner rather than later.
Trina Solar released a list of inverter brands that are compatible with its new line of high-power modules that includes SMA and Ginlong Solis. SMA says its inverters work well with such modules in utility-scale applications because they essentially act as central inverters, aggregating strings and delivering that power to a few high-power inverters. This technique allows for longer DC runs from the modules to the inverters, minimizing losses along the way.
“There’s not a lot of variability from the PV field, so aggregating those strings is a more efficient way to get the power from the PV array to the inverter. You’re also running at higher DC voltages, so your line losses are less if you run longer DC runs as opposed to running longer AC runs,” said Brett Henning, commercial product manager for SMA.
Henning said SMA’s Sunny Highpower PEAK3 inverter allows for more flexibility, should site designers need to swap any modules down the line. The string inverters don’t need to be rated for certain module watt sizes or other specifications.
“Some of our competitors will have direct string inputs and their string inputs have to be specifically rated to the individual module characteristics,” Henning said.
SMA’s smaller Sunny Tripower CORE1 inverters work well with 600-W panels in commercial applications. Instead of using the two string inputs in the inverter to reach the 30-A rating, installers would just need to plug in one string of high-power modules.
“It’s kind of interesting that the higher power panels, the ones at first blush you might think are more problematic, are actually less problematic,” Henning said. “You basically need half as many strings to get the same amount of power output.”
Ginlong says the 14 maximum power point trackers (MPPT) included in each of its Solis-(215-255)K-EHV-5G inverters makes them a good choice for projects using bifacial panels.
“In a big [bifacial] site, there will be larger variations in voltage across the site. If we have one MPPT, all this difference will be averaged out and the owner will only get probably the worst-performing string that dominates the lowest voltage, and therefore losing some efficiency,” said Gary Lam, head of Ginlong’s U.S. utility inverter product line.
Lam also said Ginlong’s high-power inverters don’t require DC fuses thanks to the multi-MPPT topology. The fuse-free design can cut down on costs and installation time.
“Usually, modules have a short-circuit rating limit and we have to pop in a fuse to protect those modules. But using our design, the modules are naturally being protected without the need for DC fuses,” he said.
Northern Electric Power
Northern Electric Power offers a unique proposition for high-power PV projects: bringing microinverters, most seen in residential rooftop systems, to large commercial designs. NEP actually calls its 500- and 600-W microinverters “macroinverters” since they’re compatible with high-powered modules.
Although some current string inverters include multiple MPPTs per unit, microinverters optimize power at the module level. That makes them especially useful for rooftop arrays where panels may need to be placed in non-linear orientations to avoid obstructions.
“When companies are looking to utilize the higher-power modules in a commercial roof, maybe there’s awkward orientations that the array needs to support, there could be shading of all kinds in a commercial roof environment. We’re definitely expecting that the macroinverter would be ideal for those kind of [uses],” said Ed Heacox, CEO of NEP.
NEP’s macroinverters can also give project owners module-level performance data, which may be increasingly important as companies begin to use fewer, higher-power panels in installations. One higher-power panel experiencing issues would be more detrimental to overall system output than one traditional panel.
Heacox said he doesn’t expect macroinverters to be used in ground-mount projects, since the uniform alignment makes string inverters better-suited and more cost-effective. But along with C&I rooftop projects, he sees a future where large-format panels are coupled with macroinverters in the residential space too.
“We expect the most innovative residential installers will try to find a way to use these kinds of products to get just a little more efficiency on their installation, more power per device,” he said.