While not completely back to “before COVID” times, this past year has felt like a return to normal solar installation activity. Projects are still going ahead, now with extra focus on product improvements that lend toward more remote accessibility and less downtime. There’s also more attention being paid to energy storage for power independence, accelerating a market already on the edge of mainstream acceptance.

There were a lot of new product announcements made quietly in 2021, for lack of the fanfare often associated with launching new products at tradeshows and conferences. Solar Power World editors kept track of everything and picked our favorite new products for the U.S. market from the past year. We are excited and eager to see products in-person at tradeshows in 2022, and here’s a collection of what we’ll be quick to check out.

These are just a few of our favorites, so be sure to visit our online database for an even more extensive list of the top products of 2021.

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Ground-mounted solar goes low-profile

As seen in Aerocompact’s CompactGround

Ground-mounted solar arrays have traditionally used a racking structure that elevates solar modules several feet or higher from the ground. It’s a tried-and-tested method for installing solar, but for a number of reasons — like zoning regulations, material costs or even neighbors who disapprove of seeing solar — customers might decide they’d prefer racking with a lower profile. If the roof is out of the question, there are smaller solar racking options for the ground that are similar to those found on flat rooftop systems.

Austrian solar structure manufacturer Aerocompact developed CompactGround, a low-profile racking solution. At its highest, CompactGround has a 40-cm gap between the panel and the ground. That condensed footprint and lower profile also brings the benefit of reduced wind exposure. In the midst of supply chain issues for the industry, Aerocompact is offering a racking solution with lower shipping and material costs. The company claims up to 1 MW of CompactGround racking can fit in a single truckload.

The system can be installed in south-facing or east-west orientation. It’s secured to the ground using either ballast blocks or ground screws and doesn’t require heavy machinery for installation. CompactGround’s flexible footing allows it to adapt to uneven ground surfaces. Aerocompact designed CompactGround to be quickly deployed, using only three primary components that make it ideal for temporary installation scenarios. It works for kilowatt-sized and larger-scale buildouts, promising higher output in the same footprint of a traditional solar ground-mount project.

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Microinverter advancements allow solar to provide daytime backup without battery

As seen in Enphase’s IQ8

Solar customers often think installing a rooftop system alone is enough to provide backup power if the grid goes down. Usually, that’s not true without a battery paired to the system. But thanks to a microinverter breakthrough, solar projects without batteries can in fact provide backup power if the grid goes down — in the daytime, at least.

“For the first time you’re able to use all the solar that you’re making, which, frankly, is what most people think solar power does already,” said Robert Pierce, senior director of product communications and content at Enphase.

Enphase’s hotly anticipated IQ8 microinverter began shipping in December 2020. The inverter uses chip technology to island homes during daytime outages, though they must be paired with an Enphase System Controller to execute that function.

Customers can choose to add storage later on to keep the home’s electricity backed up even when the sun isn’t shining. The Enphase Energy System with IQ8 comes in four different configurations — Solar Only, Sunlight Backup with no battery, Home Essentials Backup with a small battery and Full Energy Independence with a large battery. Pierce said this building-block aspect helps to make storage available to more people, no matter their backup power needs and budget.

“Until IQ8, it was challenging to properly manage customer expectations of battery design and sizing limitations and to explain different options,” said Aimee Carpenter, CEO of installation companies Solterra Solar and Good Energy Solar, in a press release. “Enabling a customer to start with any size Enphase battery and grow over time is going to make battery backup with solar a possibility for many more of our customers.”

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Centralized string inverter solutions increase uptime for utility-scale projects

As seen in Fimer’s PVS-260/PVS-300

Utility-scale solar installers in the past have had to choose between two very different inverter architectures — either the monolithic central inverter or the dispersed string inverter. Now, they have the best of both worlds with centralized string inverter skids.

Fimer is focusing all its utility-scale resources on the soon-to-be-released modular PVS-260/PVS-300 inverter skid for centralized projects. The units are made of many string inverters but are pre-assembled and tested in the factory then craned onto the site like a central inverter would be. The company said these flexible units make storage integration simple as well.

“With the utility sector predicted to grow significantly over the next few years, we wanted to offer a solution that maximizes ROI on both conventional system architectures and all other emerging system arrangements including storage, while maintaining the essential values of modularity,” said Maren Schmidt, managing director of Fimer’s utility line of business, in a press release.

String inverters are often preferable to centrals due to their modular nature and serviceability. If one goes down, the project is only missing a small portion of power production rather than a large chunk. Plus, it’s much easier to service or swap out small string inverters than large centrals, which require trained engineers to repair.

Fimer’s senior global product manager Marco Trova said this string inverter focus will allow Fimer to be more agile when adapting to new project voltages and technologies too. No longer will the manufacturer need to keep outdated parts in stock to service large central units — instead, they can update the string inverter as needed and send entire units out relatively easily when technology shifts.

The company expects its first U.S. installation to take place in Q3 of 2022.

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Early detection methods reduce lithium battery thermal runaway risk

As seen in Siemens’ FDA241 lithium-ion off-gas detector

The chances of a lithium battery going into thermal runaway — an increase in operating temperature that can lead to short-circuiting and fire — is very rare, especially when energy storage systems are rated at and installed to UL and NFPA standards. But accidents do occasionally happen, and the best way to prevent a battery-related fire is to detect thermal runaway before things get out of hand.

The difficult part is actually recognizing thermal runaway before it happens. Traditional fire detection and suppression systems (smoke detectors, sprinklers) need the presence of smoke to spur into action, but smoke in a lithium battery installation means thermal runaway has already started. Just before smoke appears though, a lithium battery will begin releasing gas as it deteriorates. Detecting that off-gas, and differentiating it from dust, smoke and other airborne particles, is paramount in a battery safety device, especially when trying to avoid false alarms and downtime at larger energy storage sites.

The Siemens FDA241 aspirating smoke detector can handle all of that and more by using blue and red wavelengths to detect off-gas particles produced in early stages of battery failure and overheating. The dual wavelengths allow the device to distinguish dust, steam, smoke and off-gas particles, signaling the device to react accordingly to the problem. For sites with high airborne dust concentrations, the FDA241 uses air filters and a “purge function” to blow-back dust particles and keep the unit clean and focused on off-gas detection. Thermal runaway may be rare, but it’s better to be safe than sorry.

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Big watts hit residential roofs

As seen in Solaria’s PowerXT 430R-PL

Watt-ratings on solar panels are quickly going up, thanks to technology advancements and improved manufacturing. Modules have been exceeding 400 W in utility-scale applications for a while now, mostly due to bigger wafers, bigger panel sizes and bonus bifacial gains. Unfortunately, modules used in residential rooftop projects can’t take advantage of those three advancements if the market wants to stick to products that can be installed by one person on a steep roof.

But some module manufacturers are finding a different way to boost power. Solaria hasn’t turned to larger wafers for its new PowerXT 430R-PL line of modules. Instead, Solaria continues to perfect the shingling method of module production, overlaying fifth-cut cells into horizontal strips for maximum power output. The shingled cells and conductive adhesive in lieu of busbars allow for PowerXT modules to fit more unobstructed silicon inside their frames, boosting power and efficiency. PowerXT 430R-PL comes in at 430 W and 20.4% efficiency, in a slightly larger-than-traditional 60-cell panel footprint.

Other companies, either through shingling or a similar process called tiling, have also recently released modules exceeding 400 W for the DG market, including JinkoSolar (415 W), LG (405 W) and REC (405 W). More powerful modules that can still be carried up a ladder and mounted to a roof by one person is a win for both the installation company and customer. The company completes higher-rated projects with fewer installers on the roof, and customers get more bang for their buck.

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Solar panel cleaning reaches new heights

As seen in SunBrush’s SunBrush Mobil Lift

If a solar panel is installed outside (and when isn’t it), it will undoubtedly accumulate debris. Anything from dust to bird droppings can cover a solar module and lead to less output and an unsatisfied system owner. The task of cleaning solar modules is approachable at ground-level, but washing the dust away on a roof or carport is a whole different challenge.

When a hose or rainwater isn’t enough to keep solar panels in hard-to-reach places clean, there’s SunBrush’s Mobil Lift. The German solar PV cleaning system provider entered the U.S. market in early 2021, bringing a range of rotating brush accessories built specifically for solar panel cleaning. These brushes mount to common machinery found on construction sites.

The Lift model mounts to the underside of the platform on a hydraulic bucket truck or a crane with a human-platform. The person piloting the platform also has control of Lift’s rotating brush and can telescopically guide the cleaner along panel rows installed at height with just a joystick. Brushes have a built-in water sprayer and can clear dust, pollution buildup, snow, moss and algae blooms from solar panel surfaces. They come standard with the company’s patented “WashTronic” float system that is paired with a warning system to ensure proper pressure on the panels. With Lift, brushes come in 14-in. diameters and lengths from 6 to 10 ft.

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