With increased consumer interest and more investment dollars entering the market, solar power is so hot right now in the United States. All that increased activity also brings improved ideas to a maturing market. From advanced solar panel technologies to multitasking inverters, the solar industry is still aiming to make things better, stronger, faster for installers and consumers, and 2023 was a great year for product announcements.
The editorial team at Solar Power World checked out as many products as possible at the various tradeshows we attended, and read through many more spec sheets and case studies, to find our favorite gadgets from the last year. Some are new, some may have been overlooked from previous years, but all are making a big difference in the everyday installation efforts of the industry. We think you’ll agree.
Be sure to visit our online database for an even more extensive list of the top products from 2023.
TOPCon technology pushes solar panels to next level
As seen in Canadian Solar’s TOPBiHiKu modules
As the solar industry settles into its “mature” status, one can reflect on previous predictions to see if targets are being met. After more than 20 years of experience, it seems solar panel technology analysts know their stuff — multicrystalline designs moved to sleek, monocrystalline models as expected; full-sized baby cells transitioned to half-cut cells three-times larger; conventional polysilicon was pushed aside for passivated emitter rear contact (PERC) technology. This consistent success put some weight behind the prediction that PERC would eventually be surpassed by tunnel oxide passivated contact (TOPCon) designs. But was the industry right?
We have our answer — yes, and 2023 was the blast-off moment. Almost every major solar panel brand announced a TOPCon model this year, and it’s the only technology anyone wanted to talk about at the RE+ tradeshow. PERC designs did the industry well for many years, but they’ve reached their limit on improving efficiency. The next step to bump efficiency is adding a tunneling oxide layer to a PERC cell, and TOPCon will carry the industry to the next breakthrough.
Canadian Solar got the party going in Q1 with mass production of its TOPCon panel with an efficiency of 25% — 1.5% higher than the average cell efficiency of mainstream PERC products on the market. The company’s new line of TOPBiHiKu (bifacial) and TOPHiKu (monofacial) modules have high power outputs too, from 420-W at the lowest for monofacial and 705-W at the highest for bifacial panels. This is the perfect tech for the utility-scale market, which looks for high-power modules that convert the most sunlight into electricity.
PVEL tests hundreds of solar panels each year for its reliability scorecard, and after only seeing one TOPCon module in 2022, the lab had 37 TOPCon panels from six manufacturers in its “Top Performer” category in 2023, including from early TOPCon supporters Jinko and Trina. The next emerging panel design may be heterojunction technology (HJT), and PVEL tested nine HJT models this year, up from two in 2022. But HJT adds a layer of amorphous silicon to crystalline silicon cells, which takes more effort to adapt on manufacturing lines than just switching to TOPCon. The easier manufacturing choice is the answer to quick efficiency gains, and we’re just at the beginning of what TOPCon can do for our mature market.
Large-scale ESS pack more energy in standard containers
As seen in HiTHIUM’s ∞Block
Large-scale energy storage systems are about as visually exciting as their residential counterparts — they’re just bigger boxes in muted, industrial tones. And just like residential ESS, grid-scale systems come in varying sizes, both in physical space and storage capacity. LG Energy Solution offers a 24-ft (287 in.) container at 2.45 MWh, and the Tesla Megapack is about 29 ft (347 in.) long and rated at 3.9 MWh. Some type of standardization would be helpful for storage developers working on multiple should-be-cookie-cutter projects, speeding up permitting and commissioning.
We’ve got some steps in the right direction: Both Hithium and CPS Energy released 5-MWh LFP energy storage systems this year using standard 20-ft container structures. Not only is the container smaller than other popular brands’, but there’s also a whole lot more storage capacity.
In addition to using larger battery modules — Hithium’s container uses 314-Ah battery modules instead of 280-Ah or smaller, which have commonly been used in the past — these 5-MWh systems can pack in more storage capacity in a smaller space because they use liquid-cooling technology to optimize system performance. Getting rid of bulky, air-cooled HVAC systems allow for the overall container to shrink and more battery modules to stack inside. Hithium has also designed a new way of positioning the battery racks so they can be closer together without fear of thermal runaway. The LFP chemistry helps in that safety consideration, too.
Of course, the energy required for each project differs, but the opportunity to have a greater energy density in a smaller space will save a lot of money on projects. And bringing some consistency to grid-scale project design will be helpful to push the storage market to new bounds.
AI technology streamlines large-scale O&M inspections
Solar projects are a relatively low-maintenance power source, but still need at least annual checks to comply with contractual and warranty obligations. For huge projects spanning many acres, that usually requires O&M technicians to walk miles of rows and inspect every panel on sites that may be very remote with challenging weather conditions. The demand for a skilled technician workforce is only rising as more enormous solar projects are installed.
“It’s a little overwhelming for somebody to go walk around and try to document an entire site when it has up to a million solar panels in it,” said Derek Chase, CEO of OnSight Technology. “The scale of the industry was really putting a lot of pressure on human resources to keep up.”
Drones are one tool that can monitor sites instead of humans, but they’re looking at arrays from above when many problems like wiring and connector issues are only visible from the ground-level, Chase said. A new AI-powered robot from OnSight Technology inspects arrays from a human’s vantage point using an optical zoom camera and thermal imaging.
The OnSight robot scans and analyzes every solar panel and every connector in a system. The robot then creates a comprehensive report, prioritizing the most urgent issues so technicians can head to the site and start repairs.
“It’s really taken the mundane aspect out of the high-dollar technicians’ hands and put them into the more technical work, where they actually have to physically swap out a solar panel or connectors or whatever the situation may be,” Chase said.
Robots are leased to customers, shipped to sites and commissioned there by OnSight technicians. From there on, the devices are operated 100% remotely.
One robot can analyze 1 mile per hour on a site and tackle between 50 and 100 MW of inspections per month. A large site will typically call for three or four robots spaced throughout the area, with multiple chargers that allow them to strategically dock when they run out of power. The robots can run for around 10 hours per day before needing a charge.
When technicians leave the job, they take their knowledge and experience along with them. But the O&M robots hang on to their findings and transmit new knowledge to a central neural network that just keeps building.
“When one robot learns something, it gets deployed to the entire fleet, so we never lose that knowledge base. It only continues to grow going forward. And that robot will stay out there forever. It’s never going to get tired of the job,” Chase said.
OnSight’s current customers include Duke Energy, McCarthy and NovaSource Power Services. OnSight didn’t disclose the current size of its fleet, but Chase says the plan is to reach 100 robots in the next three years.
The robots are also trained to do commissioning work — which, for huge projects, means scanning every single panel barcode for miles and miles.
While there’s a real fear of AI technology replacing human jobs, tedious O&M work may be better left to the bots, while the experts can spend more time fixing the problems.
New mounting solutions reduce number of rails on residential solar installs
As seen in Pegasus Solar’s SkipRail
Across market levels, solar installation is a task of making a construction project work within the confines of a space that was likely not devised with solar in mind. That is especially the case on residential rooftops, where the only objects occasionally found above the shingle, tile or metal roof line are vents or chimneys. Installing residential roof mounts is an art of retrofitting a surface meant to keep the elements out with a whole solar array and all the roof penetrations that accompany it.
Not all rooftops are built with the same surface area, so mounting rails don’t come in standard lengths. Solar installers are often responsible for cutting them to the right size for the roof, splicing spans of rails together where necessary and covering the ends with caps to conceal any sign of incisions. There are plenty of rail-less mounting options on the market, but for the project owner that would prefer the stability of rail — and the contractor who would like to carry less rail to the roof — there’s SkipRail from Pegasus Solar.
SkipRail is an interrow module clamp that can reduce the number of rails needed on a pitched-roof solar installation. It works by securing to the frames of modules between two rows and uses the metal frames as structural support. According to Pegasus Solar, SkipRail can achieve this because PV modules on the market are built to standards to withstand extreme environmental conditions — conditions that aren’t common in most U.S. states. So, this attachment can use a module’s inherent structural strength to reduce whole rows of mounting rails.
SkipRail works with the proprietary Pegasus Rail system on arrays that are built in a dual-rail layout, or with two rails supporting each panel row. On an array that would normally be composed of three panel rows with six supporting rails, SkipRail would only require four rails for the entire system by attaching between the panel rows and providing extra stability. Additionally, SkipRail electrically bonds the system.
A lot of the residential solar mounting market is focused on creating lower-profile attachments with built-in flashing — and Pegasus also released its own version of that too — turning some attention away from potential improvements to rail and mounting clamps. But there will always be installers or customers who prefer to use one mounting system over another, and perhaps there are still improvements to be made across the portfolio of racking and mounting systems on the market.
New inverter perks avoid pricey electrical panel upgrades
Going solar isn’t cheap, but knowing you’re investing in technology with an eventual return on investment is good motivation to cut the check. When that solar system can’t be installed without a costly main panel upgrade, it could be a dealbreaker.
Older homes typically have 100-amp electrical panels. Historically, these homes have been restricted by the National Electrical Code to a maximum solar inverter size of 3.8 kW — just about half of the average system size of 7.5 kW. To install a larger system, a homeowner used to have no choice but to upgrade the main panel to higher amperage.
“A lot of homeowners would be like, I don’t know if I want to do this, because all of a sudden the bill just went up $4,000 or $5,000,” said Chris Thompson, VP of product and technical marketing at SolarEdge.
Inverter manufacturers are working to eliminate that upgrade requirement for many situations using new power control system (PCS) technology.
SolarEdge is rolling out new versions of its Home Hub and Wave inverters with integrated PCS technology, which turns a formerly passive electrical panel into an active, smart one. Without this intelligent metering and control technology, the electrical code assumes the home’s load center will be running at maximum capacity, with all appliances at full output. In reality, homes are typically only using a small portion of the overall available amps. Power control systems ensure that limit won’t be exceeded.
“Your load center is basically monitoring itself and it kind of acts as a traffic cop to make sure that not too much power is being put onto the load center,” Thompson said. “We see this as making solar more accessible to more people, because it lowers the barriers to entry; it lowers the cost to add solar.”
Homeowners have full visibility into their systems and energy usage through SolarEdge’s monitoring app.
Thompson said some other inverter manufacturers are introducing PCS technology through a separate meter, but he sees a distinct advantage to integrating the capability directly into the inverters.
“It’s very easy to install, very fast to install, very low cost and very reliable in the sense it’s a very accurate meter — the communication is all built-in,” Thompson said.
Giving homeowners the capability to invest in larger solar + storage systems without the need for a main panel upgrade is becoming more important as home appliances and vehicles become increasingly electrified. Investing in more solar power is much more appealing to homeowners than shelling out money for a load center upgrade.
“You could get a much bigger solar array for $4,000 or $5,000 that will give you a much better payback, because you are getting energy out of it,” Thompson said. “People hate paying for the main panel upgrade because you can’t say, ‘Oh well, I get more solar out of it.’ It’s just a cost of doing the transaction, and it’s painful.”
Weather monitoring systems make solar production more predictable
Solar systems, like everything else on Planet Earth, live and die by the presence of the sun. Pointing PV modules toward the sky and hoping they’ll provide enough energy to support the entity they’re tied into sounds simple enough in theory. But the reality is our planet is a dynamic place that is affected by forces outside of our control. This big blue rock is spinning and hurtling through space, orbiting a giant burning star that we’re trying to harness as a power source; the planet’s skies at any time are filled with clouds that can blot out the sun or open and drop loads of rain, snow or hail to the ground below.
Whether installed in a fixed position or rotating throughout the day, there are variables that can hinder a solar module’s energy generation. And since humanity hasn’t invented a way to control the elements, the next best option is to monitor, predict and prepare for less-than-ideal conditions for solar PV. One of those solutions is the Vaisala AWS810 Solar Edition, a weather and solar irradiance monitoring station.
AWS810 measures real-time global and local diffuse light and reflected solar irradiation conditions on-site for solar projects. Vaisala designed the weather station to be simple to install, with modular componentry that can be expanded as needed. As for weather measurements, AWS810 monitors wind speed and direction, precipitation, humidity and atmospheric pressure, as well as module temperature and soiling.
The system offers optional wireless monitoring access that can connect with SCADA and cloud-based management platforms. AWS810 comes with proprietary Vaisala Weather Transmitters (WTX530), but the system can also integrate with third-party sensors. Some optional components available to AWS810 are an albedometer, rain gauge and rear-side plane of array sensor. The system is powered by an attached solar module.
Optimizing solar plant performance is a matter of anticipating and mitigating the effects of outside elements. Luckily, there are options like Vaisala’s AWS810 on the market to help those modules make more energy as the world continues to hurtle through space.