IT'S NOT OFTEN a journalist focused on the U.S. solar market gets to travel internationally for the job. When ELITE Solar invited me to Egypt for its new solar cell and panel factory unveiling, it seemed like a must-take opportunity. The facility — which is featured on page 15 — is making solar panels bound for U.S. projects, and I was able to talk with U.S. developers about the difficulty in navigating supply chains and complying with federal trade requirements. The Middle East is becoming a solar panel manufacturing hotspot, because it’s not as targeted by tariffs and has quick construction timelines.
One major theme stood out for me as I toured ELITE Solar's newest facility: Establishing solar manufacturing operations in America is expensive and a slog. ELITE Solar invested around $115 million into the combined cell and panel facility in Egypt, and it was constructed in less than 12 months. Qcells has been trying to build a cell and wafer factory in Georgia since 2023 and originally estimated spending $2.5 billion in the process.
On the two-hour drive from Cairo to ELITE's complex, it was unsurprisingly a vast desert landscape until approaching the Suez Canal Economic Zone. Huge transformers were bringing in power to the industrial area, which was peppered by shells of new buildings. The Egyptian government has been courting clean energy manufacturers to build in the zone, and all the incentives are there to have
companies quickly start. Manufacturers in the United States have to find sites that already have appropriate power supply or build their own facilities to meet their needs. On an aging and strained grid, it's a tough task in America.
How can U.S. manufacturers compete with overseas operations?
I know none of this is new information to the U.S. solar industry. Everyone's trying in their own way to change the story over here. But I also want to acknowledge that we recognize the obstacles American manufacturers face when establishing domestic supply chains. Yet many keep trying and, eventually, succeed. The achievement doesn't go unnoticed.
I look forward to sticking closer to home and visiting more American solar manufacturing setups soon, celebrating the truly herculean effort it took to get there. SPW
Kelly Pickerel
Editor in Chief kpickerel@wtwhmedia.com
Federal agency solar projects navigate component availability
Panels
SPW visits an Egyptian solar panel factory supplying U.S. projects
Inverters
Monitoring continues to reveal new insights in solar PV
Mounting
Solar projects are braced to handle earthquakes
Storage
Filling grid gaps with longduration energy storage
Extreme Projects Special Section
While solar projects are a (mostly) stationary power source, the conditions they’re built in can be quite challenging. We asked, and PV contractors shared their solutions to some extreme project scenarios.
No two solar projects are the same, and contractors are often driven to new extremes to ensure an array — whether on the roof or in the ground — gets built and comes online.
Knobelsdorff
Best-In-Class Free Air separation (1.525” between conductors)
• NEC 310.17 compliant • Fits up to (20) conductors, sized up to 1250 kcmil • Tiers adapt to different cable sizes • Tool-free snap-together install
APPROVED VENDOR LISTS US RESIDENTIAL SOLAR IS GUIDED BY
BILLY LUDT • MANAGING EDITOR
Approved vendor lists (AVLs) are a common business practice across industries, and their prominence in U.S. solar is growing. AVLs contain solar products that financiers funding projects have certified for construction.
Small-scale solar installers lost access to the 30% residential investment tax credit (25D) at the end of 2025 but can still qualify for the commercial credit (48E) if a homeowner’s solar project is third party owned (TPO) through leasing or a power purchase agreement.
“Leasing was never a big deal, but as soon as 25D went away, we’ve had to focus on 48E type applications for projects. That’s really where AVLs have come into play,” said Rob Gauchat, VP of sales and marketing for Buffalo, New York, PV contractor Solar Liberty.
TPO projects must use components from a financier’s AVL to be funded and
to qualify for the tax credit. But this shift toward relying on AVLs has narrowed the number of products available to contractors building residential arrays.
Using AVLs to build for TPO
While 25D was active, residential solar contractors could build projects using components at their discretion and owners would still receive the tax credit. Unlike commercial and utility projects, residential arrays couldn’t qualify for a 10% additional tax credit for using domestically-produced solar components. These installers had the breadth of solar components available to them.
Residential solar contractors spent the latter half of 2025 rushing to complete solar projects before the tax credit ended. Now, tax credit-eligible residential solar projects are TPO and must use components only found on AVLs.
“For us, it’s like the guardrails of what we are allowed to sell, design, install and get paid for by a TPO provider,” said Will Brown, revenue operations director at installation company Civic Renewables.
“That has especially been the case in the last six months and looking at 2026.
Equipment availability is one of the biggest up-in-the-air questions we face right now, and being able to find equipment that is AVL-compatible and will be available in three months is a huge challenge — especially when we don’t have the capital to buy a container full of modules.”
Brown doesn’t question the quality of the products on AVLs — he said the resulting arrays are excellent — but having a select pool of components to choose from has made procurement more difficult.
Options have narrowed further as tax credit qualification hinges on foreign entity of concern (FEOC) restrictions.
A solar project built on a residential rooftop. The residential market is shifting toward third party owned projects while the 48E tax credit is intact. Solar Liberty
The One Big Beautiful Bill Act shortened the timelines on all federal solar tax credits and introduced FEOC requirements for solar components. To qualify for the intact tax credits, 40% of a solar project’s components must be manufactured by companies whose ownership isn’t affiliated with certain countries — namely China. This has especially been a pain point for solar modules.
“An AVL is a means of derisking a mass purchasing of equipment, basically,” Brown said. “For us, that means having to jump through hoops and build a procurement and sales strategy that’s compliant with those requirements.”
AVLs from a financier’s perspective
National installer Palmetto launched in 2024 its own solar lease and power purchase agreement (PPA) branch called LightReach. With its own TPO platform, Palmetto LightReach owns the projects it leases for 25 years.
“AVLs existed with cash and loan, but they were a little different in that the consumer was responsible for future maintenance of their systems,” said Sean Hayes, senior VP and GM of Palmetto. “Since we own it, the stakes of, ‘Is this equipment high quality?’ is much higher.”
In TPO scenarios, a company like Palmetto is responsible for fixing or replacing failing equipment, because lease contracts have performance guarantees. If
a leased array doesn’t meet its expected performance, Palmetto cuts the customer a check for the difference in loss.
That's why Palmetto scrutinizes the products on its AVL, Hayes said.
TPO financiers are also responsible for maintaining AVLs. Palmetto has a team of employees whose only job is to vet products for the list. These employees have experience in electrical engineering, financial analysis and worked at original equipment manufacturers.
They internally review products with information provided by manufacturers: data sheets, warranties, expected degradation, real-world performance and bankability. Palmetto also uses a thirdparty engineer for additional product reporting.
“If you’re not on the AVL, you can’t have your product used,” Hayes said.
Products that are on AVLs tend to also stay on the list for a while, he said, unless the manufacturer goes out of business or ends a specific product line. Palmetto doesn't require domestic content for its projects, because procuring those products can ultimately make an array more expensive. The FEOC regulation has restricted the number of viable products available already.
“Yes, it is more restrictive, but there’s enough product and selection out there to ensure that installers have access and they’re not constricted from a supply chain side,” Hayes said. “The products are
largely what they were installing to begin with. It just may be a different module now, or they can’t install an inverter that was a new-comer.”
AVLs and safe harboring
The 48E tax credit is still active for commercial and TPO residential solar projects through 2027. When the end of that year approaches, it will be possible to “safe harbor” solar projects to qualify for the 30% tax credit past 2027. This can be done by starting construction or incurring 5% of a project’s cost by the end of July 4, 2026, and coming online by the end of 2029.
Safe harboring residential TPO projects will require procuring a backstock of components on financiers’ AVLs. Current distribution bottlenecks could affect the effectiveness of safe harboring.
In the meantime, 48E is still active and residential solar contractors are incentivized to build projects for TPO providers. Prior to 2025, Solar Liberty hadn’t built a leased solar project since 2010. Civic Renewables’ subsidiaries Green Rack, FPM Solar & Roofing and Ipsun Solar have occasionally sold TPO projects but primarily worked as subcontractors and EPCs.
However, the U.S. residential market has shifted.
“Everybody who’s doing residential needs to be looking at TPO right now,” Civic Renewables’ Brown said. SPW
TPO
Exact Solar worked alongside the Habitat for Humanity homeowners to build solar projects across five rooftops in the historic neighborhood of Strawberry Mansion in Philadelphia. Exact Solar
SOLAR POWER WORLD’S PROJECTS OF IMPACT
Anonymous donor helps Philadelphia Habitat for Humanity homes
SBILLY LUDT • MANAGING EDITOR
olar Power World 's project coverage usually focuses on arrays just starting development or construction, or on systems that have received permission to operate. However, the real effects on a community are seen during a solar project's 25-year or longer lifespan. In reaction to this, Solar Power World has started Projects of Impact, a series highlighting the effects that existing PV arrays have post-installation.
HABITAT FOR HUMANITY STRAWBERRY MANSION SOLAR PROJECT
This first Project of Impact is several solar systems built with the help of East Coast PV contractor Exact Solar and Habitat for Humanity, a longstanding American nonprofit organization that lowers the barrier to homeownership for people with low incomes.
SPW: Who all was involved in the development and construction of this project?
Aaron Nichols, solar policy and research specialist, Exact Solar: Ed McColly, who's the director of real estate development for Habitat for Humanity Philadelphia; and then there's Dave Hammes, who was our sales engineer on the project.
The project came from an anonymous donor. His stipulation was that he wanted to donate money for solar projects on Habitat for Humanity homes. Ed knew that he wanted to engage a local solar installer. He first saw our billboard but then reached out to Solarize Philly (Solarize Greater Philadelphia). We're a Solarize Philly installer, and so all of those organizations were involved and interfaced to get this going.
What's really cool about this project is that the homeowners themselves were very involved. Habitat for Humanity
has that [term], "sweat equity." These are homes that are designed for lowincome people that they buy at greatly reduced rates, but they also help build them. Our crews got to work alongside the homeowners who were finishing the inside of the houses while we were putting solar on the roofs.
SPW: What challenges did this project pose, and how did Exact Solar solve them?
Nichols: Being in a historic neighborhood was a big one. The Strawberry Mansion neighborhood of Philadelphia has some historic zoning codes that we had to work around. We had to paint all of the conduit and inverters a certain color and put a mesh
over them so they wouldn't be visible from the street.
SPW: What makes this project unique out of Exact Solar’s breadth of installations?
Nichols: We've done a lot of cool projects, but this is one of the few that has had massive social impact locally. The fact that homeowners worked on the houses alongside the crews, it's pretty amazing. And the amount of money that these families are going to save is more than the average person is going to save going solar, because the homes are also ENERGY STAR certified.
But being that these are local lowincome families who have gone on this program, it frees up more of their budget
that can go to so much more than just wasting money on rising power costs every month. Each one of the systems is going to save each home more than $40,000 over time. That’s more than $1,000 a year, which is so big for families in that situation. SPW
Members of Habitat for Humanity stand in front of these recentlybuilt homes sporting solar projects. Habitat for Humanity Philadelphia
'BUY AMERICAN' SHIFTS TO FOR GOVERNMENT SOLAR PROJECTS 'DON'T BUY CHINESE'
KELLY PICKEREL • EDITOR IN CHIEF
If there should ever be a sector that supports using Made-in-America products in construction, it would be the federal government. For decades, the government has had some type of "Buy American" stipulation for projects funded with federal dollars. More recently, the Build America Buy America (BABA) Act of 2021 requires all iron, steel, manufactured products and construction materials purchased for projects using federal funds to be made in the United States. Manufactured products are required to have 55% of their production costs originating in America.
Despite the domestic solar manufacturing market recently expanding, meeting that 55% American threshold
for manufactured products is still a tall order — for solar panels, inverters and batteries. There are waiver options for the BABA Act if there are no available domestic products, and government agencies do seek waivers when it comes to solar installations. The Dept. of Energy has applied for a BABA waiver to use inverters with automatic shutdown on a project in Alaska, citing domestic nonavailability. The U.S. Army was granted a waiver in September 2025 based on the nonavailability of domestically assembled solar panels for a project at the National Guard Readiness Center in Reno, Nevada.
While it’s sometimes impossible to use only American components on federal solar projects, there is a more
concentrated effort to at least not use Chinese products. The entire solar industry is trying to understand foreign entity of concern (FEOC) rules on private projects, and some federal agencies must now also adhere to the non-China requirement.
But figuring out those guidelines is still a work in progress — for everyone.
Solar trends in government
Before Donald Trump took office again, the federal government was encouraging solar and storage adoption within its reach. President Joe Biden's 2021 Federal Sustainability Plan called for federal facilities to use 100% carbon pollution-free electricity by 2030. The Dept. of Defense, which consistently consumes 80% of all
Solar panels are installed on a parking deck at the Louisville VA Medical Center in 2025. Michael Maddox, U.S. Army Corps of Engineers, Louisville District
energy within the U.S. government, quickly began rubber-stamping solar and storage projects. Solar was being installed at training centers, Veterans Affairs hospitals, garrisons, military housing and even considered for the Pentagon.
U.S. Army base Fort Bragg in North Carolina is home to the largest floating solar project in the Southeast. The 1.1MW solar array atop Big Muddy Lake at Camp Mackall was completed by Duke Energy and Ameresco in 2022. The project features a 2-MWh Tesla energy storage system and hundreds of LG silicon solar panels, which were assembled in the United States at the time of installation (LG has since exited the solar business).
Still, that did not stop thencongressman Michael Waltz (R-Florida) in 2023 from questioning Sec. of the U.S. Army Christine Wormuth during a House Armed Services Committee meeting on the panel supplier for the Fort Bragg installation. Sec. Wormuth incorrectly surmised that "given that most solar panels are made in China, there's a good chance that those panels were made in China."
Although the installation at Fort Bragg used American-assembled LG solar panels and adhered to existing BABA Act guidelines, or was provided the appropriate waivers, there's still a misinformed China paranoia within Congress when it comes to solar equipment. Bombshell reporting from Reuters in 2025 only added to the concern, when it seemed to confirm the existence of rogue Chinese communication devices in solar inverters.
Congressmembers are still using that cybersecurity threat in documents despite the Dept. of Energy later revealing it had found no definitive evidence of malicious software in U.S. solar projects using Chinese inverters. National laboratories inspected around 30 inverters and found two situations where communications differed from official documentation, but nothing was malicious or intentional, the DOE said.
Again, all these solar projects complied with BABA Act purchasing requirements, but Made-in-America demands on U.S. solar projects have taken a backseat to "No-China."
A 13-MW solar project was completed in August 2025 for U.S. Army Garrison Fort Polk in Louisiana. Angie Thorne, Fort Polk Public Affairs Office
FEOC rules for the feds
On Dec. 18, 2025, Trump signed into law the National Defense Authorization Act (NDAA) for Fiscal Year 2026 which authorizes appropriations for the Dept. of War (formerly Dept. of Defense) and Dept. of Energy national security programs. Included in this law is a section prohibiting the Dept. of War from purchasing solar panels or inverters from foreign entities of concern — China, Iran, North Korea and Russia.
Just like with BABA, the FEOC stipulation can be overruled if there are no alternative sources of panels or inverters, or if the Sec. of War determines there is no national security risk posed by their use. This only applies to projects directly procured by the Dept. of War and does not apply to third-party financed contracts.
While private industry is still waiting for FEOC guidelines from the Dept. of the Treasury, the Dept. of War hasn't explained how to comply with its own FEOC stipulation in the NDAA. And Congress is getting antsy.
On Jan. 14, 10 Republican members of Congress wrote to Sec. of War Pete Hegseth with concerns that the department had yet to establish "a policy addressing the national security risks of using Chinese energy infrastructure in the department's energy resiliency efforts." The congressmembers, led by Rep. Stephanie Bice of Oklahoma, cited the now-walked-back claim of Chinese spyware being used in solar inverters. They said that solar systems with rapid shutdown capabilities could be remotely activated by an "embedded adversary."
The congressmembers called for an immediate ban on the direct purchase of Chinese solar panels as well as new policies to prohibit the installation of panels and inverters from FEOCs. Hegseth and the Dept. of War have yet to respond.
Until guidelines are provided, government agencies will continue building solar and storage projects with the products available. In the Dept. of Energy BABA waiver mentioned above, project engineers have requested to use SMA inverters on the Alaska project that requires automatic shutdown. The German inverter brand would comply with assumed FEOC requirements too, showing there are plenty of non-Chinese options already used across the market. SPW
The 1.1-MW floating solar array at U.S. Army base Fort Bragg in North Carolina.
Sharilyn Wells, Fort Bragg Garrison Public Affairs Office
Can't travel to Egypt without visiting the pyramids and seeing the Great Sphinx.
Kelly Pickerel, SPW
E lI TE SO l AR RECENT lY STARTED CE l L AND PANEL MANUFACTU R ING IN EGYPT TO SUPP lY AME R I CA N P R OJECTS.
Technology
egypt usa opens its arms to the Panel
No country has affected global solar panel supply chains more than the United States. Since the boom of solar in the early 2010s, the U.S. government has chased Chinese firms across the world, initiating tariffs on products as they're "dumped" into the U.S. market at uncompetitive prices.
When the Dept. of Commerce first placed antidumping tariffs on Chinese solar panels in 2012, the manufacturers shifted production to Taiwan and then Southeast Asia. Regardless of China’s involvement, Southeast Asia became the core solar panel manufacturing spot until the United States put more tariffs
on product from Cambodia, Malaysia, Thailand and Vietnam. Operations began moving again, and now the United States is looking at India, Indonesia and Laos for more antidumping measures.
One area that hasn't seen intense supply chain scrutiny is the Middle East and Africa (MEA). The region is emerging
Panel Technology
as an ideal place to set up silicon solar panel manufacturing to avoid tariffs and supply the United States with muchneeded solar product that complies with foreign entity of concern (FEOC) requirements.
This is the background to how an American solar journalist found herself in Egypt touring a solar cell and panel manufacturing complex.
Singapore-headquartered ELITE Solar formally commissioned its 3-GW panel, 2-GW cell manufacturing complex in Egypt's Suez Canal Economic Zone (SCZone) in early January with a visit by Egyptian Prime Minister Mostafa Madbouly. U.S. partners and other guests were invited out a few weeks later.
The 450,310 ft² complex broke ground in December 2024 and incredibly began production in 12 months. ELITE Solar already has many supply agreements with U.S. project developers and signed a major deal with one developer at the grand opening.
rPlus CEO Luigi Resta said that ELITE's new Egypt facilities will benefit future generations as the world tackles climate change. He paraphrased a line from
Deuteronomy, "We drink from wells we did not dig and sit in the shade of trees we did not plant."
Factories in Egypt
ELITE Solar was founded in 2005 as ET Solar and has always had a special focus on supplying the U.S. market. In 2023, the company rebranded as ELITE Solar after splitting with its utility construction arm to focus entirely on panel manufacturing. ELITE also has cell and panel manufacturing operations in Indonesia and is establishing a solar wafer production facility in Vietnam with OCI Holdings, a long-time partner.
The company makes PERC and n-type solar panels using 182- and 210-mm
wafers. The solar panels for the utilityscale market reach 630 to 725 W with efficiencies over 23.3%.
ELITE invested approximately $115 million on the combined manufacturing facilities in Egypt, with SCZone listing employment figures at 400 for the cell plant and 460 for the panel assembly side. During the tour attended by SPW, the panel factory had more staff on the assembly floor while the cell operation was much more automated. Autonomous robots moved around the factory floor, positioning racks to move cells to their next production step. The automation at ELITE's Egypt operations is far more advanced than anything seen at manufacturing setups in the United States.
ELITE Solar's cell manufacturing operations in Egypt.
Kelly Pickerel, SPW
MEA popularity
Egypt is emerging as a clean energy manufacturing hub, and not just for solar panels. Within the SCZone, JA Solar recently announced it would make its own cell and module manufacturing complex, and Sungrow signed an agreement to make battery energy storage systems in the zone. GCL also intends to develop solar cells in Egypt, and more battery and transformer makers are looking at the country too.
The Middle East is growing in popularity, with Jinko and TCL looking at Saudi Arabia for operations, United Solar setting up polysilicon production in Oman and GameChange Solar operating tracker manufacturing in Saudi Arabia. A review of Customs and Border Protection data shows an uptick in solar cells coming from Ethiopia after Toyo's plant started production and Origin Solar shipped its first orders, likely for Canadian Solar. NE Solar/ ZNShine said it is now operating a cell factory in Nigeria, showing that solar manufacturing is expanding across Africa.
At ELITE Solar's Egyptian grand opening, both ELITE Chairman Derek Liu and OCI Chairman Woo Hyun Lee wore cowboy hats that they said represented the "cowboy spirit" of what they're doing together. Lee fashioned Liu as a "modern Genghis Khan" for ELITE's early entry into the Egyptian market, leading the way for solar domination across the region. SPW
ELITE Solar has already signed multimegawatt supply agreements with many U.S. project developers.
Kelly Pickerel, SPW
BILLY LUDT • MANAGING EDITOR
Monitoring has made inverters more essential to solar project performance
MONITORING ADVANCEMENTS HAVE made solar inverters into multi-faceted devices capable of engaging an increasing number of energy loads.
Gone are the days where solar system owners would discover their arrays were malfunctioning when they received an unexpected power bill. Now, major solar inverter manufacturers have granular monitoring measures in place to detect the slightest dip in array performance.
“There’s been a transition of monitoring being essential in the scope of a solar install,” said Brandon Davis, director of distribution sales, SMA
America. “When it started, it was largely a desktop feature. Basically, every company has a monitoring platform now.”
Looking into every power load
In their original form, solar inverters provided the crucial conversion of direct current electricity from solar panels into usable alternating current electricity. While they still do, Raghu Belur, cofounder and chief products officer of Enphase Energy, now refers to inverters with their myriad capabilities as “power management platforms.”
Solar project monitoring is possible through the inverters installed on an array. With monitoring, technicians can address problems as or before they occur.
"The reason why they have become extremely intelligent — and what the intelligence is for — is because the device is no longer simply connected to the grid," Belur said.
Initially, inverter monitoring focused on the power levels coming from the solar panels, whether the inverters were properly functioning and ultimately if the array was meeting its quoted generation expectations. Those concerns remain today but have expanded in scope.
Enphase produces microinverters used in residential solar and the commercial space. Each microinverter is installed
SMA America
Inverter Technology
Proactive and predictive maintenance
The data compiled by monitoring helps system owners and technicians make maintenance decisions. Inverters will flag underperforming arrays and attempt to diagnose the error, be it degrading modules or a faulty component, and manufacturers can dispatch a technician or order replacement parts to fix alerted issues.
“You can’t do this if you don’t have data,” Belur said. “You need detailed data, not just about your solar. You need data about all of the flexible resources that are behind the meter — and at the meter, if you have a meter collar.”
Inverter manufacturers are implementing artificial intelligence “agents” to parse the massive amounts of data generated by granular inverter monitoring. Belur said Enphase is gathering terabytes of project data daily.
Having these measures in place for predictive maintenance has increased solar system uptimes. A malfunctioning solar array is ultimately costing the system owner money, so maximizing performance and keeping systems online is paramount.
“The key part of monitoring is ensuring your customer is getting the financial returns that you guaranteed when you sold the system,” Davis said. “Peace of mind is the biggest thing.”
There are also opportunities to modernize solar arrays that were installed before inverter monitoring became the standard. SMA is pushing an initiative to replace legacy inverters with models that are monitoring-enabled. Repowering these projects can increase their longevity and help legacy components operate at new levels of efficiency.
Inverter monitoring is expected to progress further in expanding load management capabilities, namely within buildings. The original function of solar inverters remains the same, but they are not only converting electricity, but converting how solar power engages with the grid. SPW
Inverter manufacturers have developed applications for project owners to closely monitor their arrays’ performance. Enphase Energy
Enphase Energy
BILLY LUDT • MANAGING EDITOR
Designing solar projects to withstand earthquakes
EARTHQUAKES DON’T RANK highly as a natural risk to solar projects despite the isolated devastation they can cause. Wind, snow and even salt buildup from ocean breezes broadly cause solar technicians more headaches than seismic activity.
The reason earthquakes aren’t a common concern for solar is two-fold. The first is that seismic activity in the United States is limited mostly to the West Coast, primarily in California and further north in Alaska.
Secondly, project designers consider the lateral movement in structures caused by earthquakes to be similar to wind. The oft-used phrase of solar panels becoming “sails” when hit by a strong gust has made manufacturers reinforce the attachment strengths of their racking and mounts, so that precaution for wind also prepares arrays for earthquakes.
Earthquakes can be a risk to groundmounted solar projects, but they are new structures that can be engineered to account for seismic activity and other environmental pressures. Rooftop solar is trickier, because it is mostly installed on existing structures built to certain standards that might not anticipate PV.
“When you’re doing engineering, the biggest force tends to be the thing that makes you strengthen the system up to
a certain point, and that is consistently wind,” said Ben May, founder and CEO of Alaska Solar, a residential and commercial contractor in the Last Frontier. “Yes, it has to be strong for seismic, but it has to be stronger for wind. Where seismic has come into play … it’s this factor that has precluded doing ballasted systems, unfortunately.”
Buildings are rated to withstand a certain amount of downward pressure persquare-foot on their roofs. In regions that experience earthquakes frequently, the additional weight of a ballasted system can exceed those limits.
This is especially pertinent in Alaska, a state that has earthquakes about every 15 minutes and experienced the second strongest earthquake in recorded global history. Combined with the downward pressure of snowfall, ballasted solar arrays on rooftops become even trickier.
“The moment you put that weight on top of a building and then shake it, the leverage, or the moment of it, becomes really significant and important,” May said. “If you increase that moment by putting ballasts up there, then whatever the building was built for is exceeded and doesn’t work.”
But ballasts aren’t ruled out entirely for these types of projects. It’s possible to
design a ballasted solar array to account for seismic displacement by giving array rows setbacks from obstructions and the roof’s edge.
Directly attaching to a roof with seismic anchors doesn’t require the same setbacks as a ballasted system, besides mandatory fire access. Direct attachment reduces a solar project’s weight on a building compared to a ballasted project. It’s the lighter option, but it raises concerns with building owners about drilling holes into roofs — despite the waterproofing involved.
However, attaching to the roof makes the array an extension of the building, which helps distribute environmental pressures throughout the structure.
“There will be a transition when you go from the rack into the building,” said Ahmed Youssef, senior project manager at Pure Power Engineering. “You have a positive connection between both of them to transfer the load from the rack system into the building.”
Buildings located in regions with seismic activity often have additional structural bracing measures to withstand lateral movements — solid shear walls on building exteriors; moment-resisting frames attached to structural columns and beams; or braced frames placed between
Earthquakes don’t pose a great threat to solar projects. Project engineers and racking manufacturers have accounted for seismic activities. Alaska Solar
ModulAir® Free-air Cable Management
structural beams. These reinforcements can also help support a solar array.
Enstall, a company of brands in solar racking like IronRidge, engineers its mounts for projects based on a site’s controlling loads — or the prevailing conditions there. For seismic activity, Enstall consults the American Society of Civil Engineers’ historical studies on earthquakes.
“You design to an earthquake that has a uniform risk category of a failure of a building or a structure,” said Matt Kuzila, manager of structural engineering at Enstall. “We generally look at what could be the worst-case scenario, because we don’t know where a specific product is going to be installed. So, we look at all the worst cases within the 50 states. We’ll then take that load and test to it.”
Every company Solar Power World interviewed for this story said it hadn’t witnessed any damage to solar projects from earthquakes. The industry has taken steps to mitigate the seismic lateral force for both ground-mounted and rooftop solar projects.
“The beauty of solar is solar racking and panels have strength through flexibility,” May said. “Aluminum is the main metal for residential and commercial rooftops. It’s lovely. It bends, but it doesn’t break. A good tree flexes in the wind, and the next day it’s the same as it was.” SPW
solar project directly attached to the building’s roof. Alaska Solar
EVERY SOLAR PROJECT HAS AN END OF LIFE
WE MAKE SURE IT ENDS AS CLEAN AS IT BEGAN – NOT IN A LANDFILL
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From rooftop removals to utility-scale repowers
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Supports circular economy and sustainability commitments
When your solar project sunsets, we make sure it ends clean – and stays that way
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KELLY PICKEREL • EDITOR IN CHIEF
The growing need for longduration energy storage in the US
WHILE ALL HAVING the same function — taking energy, storing it, then releasing it — energy storage systems come in many different types. Whether thermal, electrochemical, mechanical or an emerging category, each energy storage system is important to the electrical grid of today and tomorrow. But when it comes to much-needed long-duration energy storage (LDES), certain types shine brighter. As grid-scale energy storage construction shifts away from
effectively than a bank of lithium batteries, said Priya Shrivastava, research manager at Wood Mackenzie.
"Lithium-ion batteries generally exhibit higher capital costs per kilowatt for long-duration applications and experience relatively high degradation rates (approximately 1.5 to 3%)," she said. "LDES technologies typically feature significantly lower capital costs per kilowatt and minimal degradation (<1%), allowing for longer discharge durations
hydropower. You can't indefinitely increase your pumped storage. You need to find some other solutions to complement that technology," said Brandon Owens, VP of innovation and research at the New York State Energy Research and Development Authority (NYSERDA). "We have funded and are looking at demonstration technologies across the range of electrical, thermal, mechanical and chemical storage. We're trying to invest in those other technologies and move them to
The most common LDES is pumped hydro-storage, like this system at the Rock Island Dam on the Columbia River in Washington State. Karl Specht, shared with U.S. DOE
"There's an increasing need for longerduration as the energy system across the globe transitions. You're electrifying transportation and buildings. You're adding more intermittent or variable resources to the grid, so you're creating this need for longer-duration storage," Owens said. "You're talking about time shifting, either day to night or seasonal. The need to fill gaps is growing over time.
"We've gained some operational experience on [LDES] technologies through pilots in demonstration. There's a lot of learnings that have happened, but they're not focused on, 'We learned that iron-air is the ultimate solution and that's where we need to put all our money,'" Owens continued. "We've learned that it's really use-case dependent, and that’s why we continue to diversify our research spend in this area."
Already well-versed in the benefits of short-duration lithium BESS, California
is also exploring LDES, said Kris Van Vactor, director of power resources for community choice aggregator (CCA) Silicon Valley Clean Energy (SVCE).
"In time, our [power demand vs. generation] peak is going to become much shallower, not going to be as pointy. In order to shift everything down, you need longer periods of charging to change the shape of the portfolio. That's really why the eight-hour product is becoming more popular," he said. "When a peak goes up like a mountain, you only need a two-hour or four-hour slice to take the peak off. But if it's like a hill, then you need an eighthour piece to reduce everything down."
There are efforts to make lithium-ion batteries perform better in long-duration setups.
The ∞Power system from Hithium is a 6.9-MW BESS that uses eight-hour lithium cells to reach 55.2 MWh. Hithium
Storage Technology
California Community Power (CC Power), a joint agency of nine California CCAs including SVCE, has been testing LDES designs for years, issuing its first major request for projects in 2020. CC Power recently began discussing buying power from a 500-MW compressed-air system with an eight-hour discharge. A compressed-air system works similarly to a pumped-hydro system, using air and water movement to turn turbines. If greenlit, the Hydrostor-developed Willow Rock compressed-air LDES project would be sited in Kern County, California, and come online by the end of 2030. This would be the first non-lithium LDES project for SVCE, and that’s why the SVCE board is encouraging CC Power to sign on as an offtaker on the Willow Rock project.
"The value proposition of CC Power is that it's nine CCAs. We bind together to find projects like this that we can be supportive of. It's not experimental because it's somewhat proven, but the money hasn't really adopted it," Van Vactor said. "We can support the project and improve the diversity of our portfolio. This is about trying to find
other technologies that can fill the role of lithium-ion. You don't want to have too many eggs in one basket."
There are some promising trends for LDES. A recent study by EPRI and the LDES Council found that the cost of many long-duration energy storage technologies is expected to decline by 2030, reflecting continued technology development and manufacturing scale up. And that could mean lithium re-enters the LDES conversation.
Although not typically seen in LDES, advances in lithium storage durations are ongoing. Chinese lithium battery developer Hithium unveiled in December its ∞Power system — a 6.9-MW BESS that uses eight-hour lithium cells to reach 55.2 MWh. Hithium says the eighthour cells reach 1,300 Ah and reduce system component count by 30%.
Wood Mackenzie's Shrivastava said it's a promising advancement for lithium LDES.
"Hithium’s proprietary ultra-thick electrode technology, which overcomes key challenges such as electrode cracking, slow ion and electron transport and limited electrolyte penetration, enables higher
energy storage at lower cost as well as increasing system density and lifetime," she said, while also predicting that an eight-hour lithium system will be twice as large in its footprint as a four-hour system.
Owens with NYSERDA said he welcomes any developments in lithium LDES.
"We're comfortable with lithiumion batteries in general, because of the installed base and the experience that market has with those technologies. We welcome any expansion. We're talking about moving it from short duration to medium duration. We absolutely would welcome that as a technology option," he said. "We're not necessarily partial to lithium-ion, but if it fills a solution and it can do that cost effectively, we'd certainly welcome that in the marketplace."
Those parties motivated to deploy the technology will continue to explore LDES options.
"We've put a lot of money in longduration storage over the last several years, and we've got more investment plans over the next five years," Owens said. SPW
A rendering of the proposed 500-MW Willow Rock compressed-air LDES system. Hydrostor
SPECIAL SECTION
Unless installing solar on every home in a new housing development, it's rare that a contractor will complete the same project twice. Power needs, landscapes and equipment differ on arrays across the country and even in the same neighborhood. The Solar Power World team thought it'd be interesting to ask solar and storage installers about extreme situations and how best to still make the sale. From building in muddy conditions to working on steep roofs, there's always something unexpected around the corner. Here's how installers get the jobs done — extremely well.
WHERE WOULD YOU INSTALL A BATTERY FOR A HOUSE WITHOUT A GARAGE?
INSTALLING ENERGY STORAGE in our region is rarely as simple as mounting a battery on a garage wall near the utility meter. Many homes in the coastal Carolinas are older and don’t have garages, while some newer homes aren’t designed for first-floor installations. In coastal floodplains, battery equipment often must be installed on the second story to keep it above flood levels. This can mean placing batteries on elevated platforms or in interior utility rooms. While some homes already have suitable spaces, installing equipment there and meeting clearance requirements requires extra care and precision. Our team works closely with homeowners and local authorities to develop and execute a safe, compliant plan.
Not every coastal home needs elevated equipment, and some do have usable garages. Even in those cases, exterior installation may be the best option. Placing the battery near the utility meter is often the most efficient and cost-effective solution and may be the only practical choice depending on the layout of the garage, meter and electrical panel. Fortunately, many modern battery systems are built with durable enclosures and warranties designed for outdoor use and harsh coastal conditions.
-GABE AMEY • CHIEF MARKETING OFFICER CAPE FEAR SOLAR SYSTEMS
HOW
WOULD YOU PITCH SOLAR AND STORAGE IN AN AREA WITH A VPP?
SOLAR CUSTOMERS IN the Northeast are already adding storage to their systems, but the option of participating in a VPP really cements the deal. VPPs have been a more recent advantage to relay to customers. Through smart software, a system automatically dispatches stored energy during peak demand, stabilizing the grid and earning the customer credits or payments from utilities like Con Edison or Eversource. No extra effort is required, and the customer’s battery charges cheaply off peak and sells high when the grid needs it most. We don’t alter the size of a solar system to take advantage of the VPP benefits; it’s just an added perk for investing in solar and energy storage in our region.
-CARLO LANZA • PRESIDENT • HARVEST POWER
HOW DO YOU DESIGN A SOLAR PROJECT FOR A HOUSEHOLD LOOKING TO PURCHASE AN EV?
IN OUR REGION of southern California, an EV charger installed at home uses, on average, an additional 10 kWh nightly. When designing a residential solar system, we measure loads over a monthly period of time. This additional 300 kWh for an EV is added to that total. The average monthly load on a desert home is around 1,500 kWh, so we add that EV charger load to reach 1,800 kWh. With a non-EV home typically needing at least 11 kW of solar, this would increase the size of a solar array for an EV-owning household to about 13 kW. Adding four solar modules would provide the additional generation to offset the driving patterns of a person using their EV for 12,000 miles annually.
-VINCENT
BATTAGLIA • CEO • RENOVA ENERGY
HOW WOULD YOU INSTALL PANELS ON A SURFACE STEEPER THAN 45°?
WHEN WE’RE FACED with a roof pitch steeper than 45°, the first priority is simple: safety. Before any tools come out, our crew performs a full site assessment — evaluating roof condition, access points, tie-off locations and weather exposure.
We dispatch only highly trained, experienced installers for these environments. OSHA-compliant fall protection is non-negotiable: full harness systems, properly-rated anchors, roof brackets, guardrails when possible and controlled access zones. The anchoring and attachment process itself remains structurally consistent with our engineering standards, but the execution requires heightened awareness, balance and coordination.
On extreme pitches, staging and material handling become just as critical as installation. We plan panel lifts carefully, secure materials to prevent sliding and sequence installation to minimize unnecessary movement on the roof. Weather conditions are closely monitored, and we never rush timelines at the expense of safety. Ultimately, the key factors are preparation, skilled labor and mindset. Steep surfaces demand respect, but with the right training, equipment and teamwork, we figure it out safely and efficiently every time.
-ANDREW DUBKOV • HEAD OF RESIDENTIAL OPERATIONS UNITY SOLAR GROUP
WHAT’S THE BEST WAY TO MANAGE MUD/GROUND CONDITIONS WHEN INSTALLING A LARGE-SCALE PROJECT?
MANAGING MUD, snow and poor ground conditions on a large-scale solar project is largely a matter of early planning. When wet-weather rules are not clearly defined in advance, productivity often suffers as crews are forced to “figure it out” in the field.
These conditions can be effectively managed through proactive coordination of deliveries and construction timelines before impactful weather occurs. When weather impacts are unavoidable, mitigation measures may include the use of tracked equipment, additional temporary laydown yards, clearly defined onsite traffic routes and limiting vehicle movement during thawing periods. Taking these steps early helps maintain productivity and reduces risk in challenging ground conditions.
-ERIN BROSSARD • DIRECTOR OF ENERGY OPERATIONS KNOBELSDORFF
WHAT SITE SECURITY WOULD YOU USE FOR A SOLAR PROJECT NEAR A MAJOR HIGHWAY?
SOLAR PROJECTS ARE unique in that they are built over several acres, often spanning large, open landscapes that require thoughtful planning and protection. For solar projects located near major highways, robust site security is essential to protect equipment, ensure operational reliability and maintain public safety. Our approach begins with installing tall game fencing around each module region to clearly define boundaries and deter unauthorized access. Appropriately spaced remote camera stations provide continuous monitoring and enable quick detection and response to unusual activity. Clear, visible signage reinforces safety expectations for both team members and the public. Staging material away from the view of local traffic also helps prevent curiosity-driven intrusions. The Lapeer Solar Array, which Barton Malow successfully completed for DTE Energy off Michigan’s Interstate 69, demonstrates how sites can be effectively secured and maintained even when located near a major highway.
-RYAN JOHNSTON • PROJECT DIRECTOR BARTON MALOW
WHAT DO YOU CONSIDER IN PROJECT DESIGN AND COMPONENT SELECTION FOR A PROJECT ENVIRONMENT REGULARLY EXPERIENCING TEMPERATURES ABOVE 90°F?
THERMAL MANAGEMENT IS a critical factor in designing utility-scale solar and energy storage systems — especially in environments where ambient temperatures regularly exceed 90°F. High heat impacts electrical performance, so every component must be evaluated and adjusted for expected operating conditions, not just nominal ratings.
Most electrical components, including inverters and conductors, experience performance degradation at elevated temperatures. For example, inverters may be rated for full capacity up to 30°C (86°F) but often derate by a small percentage for every degree above that. In locations exceeding 40°C (104°F), output can drop
-OMAR AHMED • VP OF ENGINEERING • DEPCOM
below 95%. Conductors face similar constraints; higher temperatures reduce their current-carrying capacity, which requires upsizing or using additional runs.
To compensate, designers must temperaturecorrect system performance expectations and adjust the quantity or size of components accordingly. This ensures long-term reliability, safety, and optimal energy yield. It’s essential to validate each component’s thermal characteristics directly with the manufacturer. This data-driven approach allows the design team to accurately model system behavior under real-world conditions and ensure consistent, bankable performance throughout the system’s lifecycle.
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