Innovations in all areas of solar technology help the market grow despite—and in response to—solar restrictions by policymakers and utilities. This year’s assembly of Top Products aim to help contractors increase flexibility in system design and enter new markets.
Panel-level storage where inverters and optimizers work at each individual solar panel can help solar+storage expand in applications where big batteries won’t fit. Back-contact panel technology opens the possibility of unobstructed power generation from the front of modules. Four-module residential microinverters can harvest more energy with fewer components—meaning fewer hours of installation labor too.
We hope you enjoy the Top Products the SPW editors chose this year after scouring tradeshow floors and posting hundreds of press releases. We do it for you!
And to see a full grouping of the Top Products of 2018, please view our main page here.
High-voltage string inverters increase system flexibility
As seen in ABB’s PVS-175-TL string inverter
ABB’s 1,500-V PVS-175-TL utility-scale string inverters are one example of going big in capacity to increase flexibility and lower system costs. This inverter can be decentralized and sited closer to the panels, making it a good fit for challenging system designs with weight limitations.
The modular, two-part commercial string inverter is similar to ABB’s residential inverter, and just as easy to install. It can be attached to the existing solar module’s mounting system.
Up to 24 strings can connect directly to the inverter’s wiring compartment with integrated DC disconnect and AC wiring section with optional AC disconnect. There’s no need for a separate DC combiner box. Installers can also eliminate the fuses needed to parallel strings, reducing mismatch losses.
High-voltage inverters reduce costs on projects. The modular design means fewer inverters and AC recombiners are required for solar projects. Balance-of-system equipment is integrated in the inverter, so there’s no need to purchase additional parts. The 1,500-V inverter also improves the levelized cost of electricity (LCOE) for utility-scale installations.
Installers looking for plug-and-play solutions compatible with the latest voltage trends will find an ideal solution with ABB’s utility-scale string inverter.
Concrete-free ballast design offers more installation options to contractors
As seen in APA Solar Racking’s Geoballast Foundation
Just because something is tried-and-true doesn’t mean it’s the one-and-only option. Large concrete blocks have successfully been used for years as ballast on ground-mount solar arrays that cannot penetrate the ground. Blocks are shipped or poured in place. But on some of the most temperamental ground conditions (landfills, brownfields), heavy concrete trucks probably shouldn’t be driven around.
Mounting system manufacturer APA Solar Racking has years of knowledge installing ballasted solar projects and found that using wet concrete added too many extra steps and increased man-hours on every job. The company introduced its Geoballast Foundation this year, which uses a wire basket to hold quarry rock in place of concrete blocks to secure solar arrays down. The galvanized steel gabion baskets are shipped flat and only take a few minutes to be unfolded and stabilized with an anchor tube that connects to the rest of the racking hardware.
The baskets are easily moved with a skid steer or carried to each location before filling with quarry rock or other materials. By using locally sourced rock, the Geoballast Foundation costs a fraction of concrete pouring. And crews don’t have to wait for concrete mixer trucks to deliver, so project bottlenecks and scheduling headaches are reduced.
Four-module residential microinverters harvest more energy with fewer components
As seen in APsystems’ QS1 microinverter
String inverters and microinverters each have pros and cons in residential installations, but a new microinverter aims to use each product’s best characteristics to make installers’ jobs easier. APsystems’ QS1 residential quad microinverter converts power at the panel level—but can do so for four modules per inverter.
The QS1 is the first microinverter to perform such a feat, and it can also accommodate high-output PV panels up to 375 W, offering 300-WAC output per channel. It comes with wider MPPT voltage range for greater energy harvest during low-light conditions.
The hardworking four-module microinverter is competitively priced because it requires less effort to manufacture and is therefore cheaper to produce. Installers will save money and time on installations since there are fewer products to install. The QS1 is fully compatible with APsystems’ other microinverters, so it can work in retrofit jobs as well as new solar projects.
Since this single microinverter can take the place of four, there are fewer points of failure. This solution cuts costs and eases installation burdens on installers.
More options in power electronics means installers may be able to solarize more roofs that may not have been feasible before the latest technological advancements.
The Commercial Buildings Energy Consumption Survey estimated there were 5.6 million commercial buildings in the United States in 2012, comprising 87 billion sq. ft. That’s a lot of underutilized roof space prime for solar generation, as long as the buildings can structurally support solar arrays. Commercial rooftops are often free from shade and obstructions (besides some vents and HVAC systems), and there’s no grass to mow. Trackers could squeeze more power out of each panel, but they’re not the obvious choice for flat roofs—until now.
Defying the impossible, Edisun Microgrids’ PV Booster is a single-axis tracker for individual panels on the roof. Company reps found that if you modularized the tracker, individual point loads could be reduced, and a tracker could successfully work on a roof. The panel pivots from the front edge in a carousel design to keep the whole system closer to the roofline.
Panel manufacturer JinkoSolar took notice. The two companies have partnered on a new performance bundle of Jinko’s high-efficiency, 72-cell, 400-W Eagle G2 modules and Edisun’s PV Booster, called the Eagle PowerTrack. The individual trackers are spaced out in a row, allowing the panels to move freely in a circle at a permanent tilt angle. The high-efficiency, high-power modules combined with the tracker yields 30% more energy than traditional, stationary panels on a flat roof. The Eagle PowerTrack is a system that could significantly increase the return on investment for C&I customers.
Lightweight, easy-to-install systems encourage more solar on commercial rooftops
As seen in Esdec’s FlatFix system
The main issue with solar on flat commercial rooftops is weight—how to distribute it and manage its long-term care. Systems can’t be too heavy because the building may not be able to support that extra weight. And when concrete ballast is used, installers have to be mindful of where it’s positioned, so the mounts and ballast don’t damage the roofing membrane during normal array movement with thermal expansion.
The Esdec FlatFix system solves both these issues and more. The commercial system is not new—Esdec has 1.8 GW installed in Europe—but it is new to the U.S. market. FlatFix is made primarily out of lightweight, fiberglass-reinforced plastics. The racks attach to self-leveling baseplates that have “thermal-effect compensation” built in. The baseplates stay secure, but the racks can rotate in their connections as the roof constricts and contracts. Ballast trays are elevated above the roof, running under the long-side of the panels. The ballast and the mounts never have the chance to grind into the roofing membrane.
Esdec was started by two Dutch solar installers, and the company continues to make products with direct installer input. Not only is the FlatFix system easy on a roof, it’s easy on the installers. Rails audibly snap together, and the only real hands-on, tooled assembly is tightening clamps. Wire management is integrated into the core mounts, and accessories like optimizer clips also snap on. With fewer weight and labor concerns, the FlatFix system will increase commercial solar rooftop installations in the United States.
3D aerial mapping helps installers find more qualified prospects
As seen in Nearmap’s MapBrowser
Nearmap’s new MapBrowser is a complete measurement toolset that allows installers to measure roof-pitch, height, width and area from high-resolution oblique aerial images—before they ever set foot on a prospect’s property.
Nearmap’s technology offers a photorealistic perspective of rooftops from all angles using 3D textured mesh. To collect such detailed data, the company uses cameras mounted on fixed-wing aircraft to take multiple angles and record elevation data of rooftops. Users can view the images from three perspectives: vertical, panorama or oblique. The sharp images allow contractors to confirm details they would’ve previously had to do in person.
This tool reduces onsite visits during the quoting and planning stages of projects and complements installers’ remote roof and site inspection workflows. It also allows installers to remotely calculate coverage, material and other costs. The imagery can be annotated with notes, drawings and measurements that provide details of a solar project plan.
MapBrowser can help installers prospect more efficiently by using precise aerial maps. Once they qualify a lead from their desks, they can send potential clients a detailed design proposal with up-to-date, high-resolution aerial imagery. Starting the conversation at this well-informed place is sure to result in more solar customers.
Back-contact technology allows unobstructed power generation from front of module
As seen in Silfab Solar’s SLA-MWT 320-340 modules
A crystalline silicon solar panel is not just an average, boring solar panel anymore. It could have PERC technology and perform better in low-light conditions. It could be bifacial and produce power from both sides of its cells. It could have half-cut cells and lower resistive losses. If the solar panel does not have at least one unique feature, what’s the point?
Once a feature only promoted by SunPower, back-contact technology just might be the next big trend, precisely because of SunPower’s usage. SunPower’s interdigitated back contact (IBC) modules were excluded from the 30% solar panel tariffs this year because of their unique manufacturing process. LG also produces back-contact modules, and now Silfab Solar is joining the game, and more are sure to follow suit.
By connecting all the electrical contacts on the back of the cell, the front of the module is free of busbars and can convert more light into energy. Silfab is using DSM’s conductive black backsheet on its SLA-MWT line of back-contact modules to connect neighboring cells to transport even more power. With unobstructed front-side generation and a conductive backsheet, Silfab claims its back-contact modules produce 30% more power than conventional modules.
Panel-level storage could open up solar+storage market when big batteries just don’t fit
As seen in Yotta Solar’s SolarLEAF
If inverters and optimizers can work at each individual solar panel, one could argue that panel-level storage shouldn’t be too difficult. But it is. Batteries degrade faster under extreme heat or cold, and it gets really hot underneath solar panels and sometimes they’re installed in sub-zero conditions. With solar+storage still in its beginning stages, it’s a little audacious for storage manufacturers to skip the push for increased market adoption to focus on panel-level issues.
Yotta Solar likes to think boldly. It will release in 2019 the SolarLEAF, a panel-level energy storage device that is on the right track to solving issues with modularized storage. It’s not the first “microstorage” device (bankrupt JLM Energy has its Phazr system) but SolarLEAF is the first with 100% passive thermal regulation, so no extra energy is used to shield the small battery from hot and freezing temperatures—batteries are kept between 50°F and 95°F. The battery packs attach behind standard 60- to 96-cell panels at the time of installation or as a retrofit. Their plug-and-play design allows for easy energy storage integration without heavy equipment or bulky enclosures.
With the industry warming up to DC-coupled solar+storage systems, panel-level storage falls in line. The SolarLEAF doesn’t require a separate inverter since it’s looped in to the DC side already, and this improves overall solar+storage system costs and simplifies the interconnection process. At 35 lbs, the SolarLEAF battery packs are bulkier than the average MLPE, so this setup is not the best option for residential installs on pitched roofs. But for commercial projects with increased room behind panels, the SolarLEAF is a great solar+storage alternative when large-scale lithium-ion batteries are just not possible.