The Solar Product Registry Set to Boost Solar Deployment

An international research team of photovoltaics scientists has taken a crucial step toward the industrialization of perovskite silicon tandem solar cells. They demonstrated that passivation of the perovskite top cell is possible in combination with textured silicon bottom cells featuring large pyramid size, which are the current industry standard for solar cells. Additionally, they discovered that the passivation affects the entire perovskite layer – unlike silicon, where surface treatment only influences the upper layers – leading to further efficiency improvements. The PV researchers from King Abdullah University of Science and Technology (KAUST), University of Freiburg and Fraunhofer Institute for Solar Energy Systems ISE presented their technological and scientific innovations for the passivation of perovskite top cells in the journal Science. The full paper can be accessed for free at https://www.science.org/doi/10.1126/science.adx1745. 

Perovskite silicon tandem solar cells consist of a perovskite top cell and a silicon bottom cell. They represent the next major technological advancement in photovoltaics, as silicon solar cell development is approaching its physical maximum efficiency of 29.4 percent for converting sunlight into electricity.

For large-scale production of these tandem solar cells, using a standard silicon solar cell for the bottom cell would be advantageous, as their manufacturing processes are already well established. These solar cells are textured to increase their surface area, enhancing efficiency, but this texturization also complicates the deposition of the perovskite layer. Achieving high-quality surface passivation of the perovskite top cell on the pyramid-like surface had not yet been accomplished.

“So far, effective passivation has not been fully harnessed on textured perovskite silicon tandem solar cells, with prior success largely confined to flat-front architectures. But we have now managed excellent passivation by depositing 1,3-diaminopropane dihydroiodide on the uneven perovskite surface,” said Dr. Oussama Er-Raji, the lead author of the paper and a scientist at Fraunhofer ISE. The passivated tandem solar cells achieved a conversion efficiency of up to 33.1 percent, with an open-circuit voltage of 2.01 volts.

The scientists also observed that the passivation of the perovskite top cell improved the conductivity and thus the fill factor of the cell. They proved that this improvement is due to a deep field effect resulting from the passivation. In silicon solar cells, the passivation acts only close to the surface, whereas in perovskite solar cells, the surface treatment impacts the entire absorber, enhancing its bulk properties.

“This realization provides a solid foundation for all future research in this area,” said Prof. Stefaan De Wolf, Professor of Materials Science and Engineering and Applied Physics at KAUST. “It enhances our understanding of the processes occurring in the top cell while converting light into electricity, enabling scientists to leverage this knowledge to develop better tandem solar cells.”

“Surface passivation of solar cells is not just a nice-to-have feature; it is an essential booster for their efficiency and stability,” adds Prof. Stefan Glunz, Professor of Photovoltaic Energy Conversion at the University of Freiburg and Director of the Photovoltaics Division at Fraunhofer ISE. “For today’s silicon solar cells, surface passivation was the key for high efficiencies in industrial production, and it is encouraging that the PV industry will benefit from these positive effects for perovskite silicon tandem solar cells as well.”

The researchers’ findings build on work in the Fraunhofer lighthouse project MaNiTU as well as the projects PrEsto and Perle, both funded by the Federal Ministry for Economic Affairs and Energy.

Fraunhofer Institute for Solar Energy Systems ISE | https://www.ise.fraunhofer.de/en

Green Rain Energy Holdings Inc. (OTC: GREH) (“Green Rain” or the “Company”), a clean-energy company dedicated to reshaping the future of sustainable power, today confirmed that it is in advanced negotiations for a landmark renewable energy project in Southern California.

The project envisions the development of a next-generation solar energy installation, strategically positioned on a 4.2-acre semi-rural property in San Diego County. The site is owned by a well-known African American author, whose commitment to sustainability and community wellness complements Green Rain’s mission to deliver transformative energy solutions that generate both economic returns and social impact.

A Unique Intersection of Energy, Community, and Vision

The initiative will combine renewable power production with community-focused amenities, representing a first-of-its-kind project in the region. The property is being designed as an eco-retreat and wellness hub, complete with resort-style accommodations, organic farming, recreational amenities, and teaching kitchens – all powered and supported by renewable energy.

Preliminary negotiations include:

• A solar generation facility designed to deliver reliable, clean electricity to the grid while offsetting on-site demand.
• Battery storage systems that provide resiliency, peak-shaving, and backup power.
• Potential solar carport installations, maximizing usable space and blending function with sustainability.
• Participation in SDG&E’s low-income assistance program, dedicating a portion of power to reduce utility costs for disadvantaged families.
• Flexible financial models, including land lease agreements, Power Purchase Agreements (PPAs), and joint ventures, designed to optimize shareholder value.

Positioning for Growth in a Multi-Billion Dollar Market

California is targeting 100% renewable energy by 2050, and San Diego Gas & Electric (SDG&E) remains one of the fastest-growing markets for distributed renewable power. With demand for solar and storage solutions at record highs, Green Rain believes this negotiation marks the beginning of a transformational growth phase for the Company.

“This project positions Green Rain at the forefront of the clean-energy transition in one of the nation’s most competitive renewable energy markets,” said Alfredo Papadakis, CEO of Green Rain Energy Holdings Inc. “We are not only pursuing profitability – we are demonstrating how renewable energy can uplift communities, support California’s clean-energy mandate, and establish a blueprint for future developments nationwide.”

Strategic Synergy with Community Development

The property itself is undergoing parallel developments, including a resort-style main house, additional dwelling units for medical professionals, off-grid tiny homes for short-term rental, and organic farming initiatives aimed at community empowerment and food sustainability.

By integrating a large-scale solar component, the project will become a showcase for how renewable energy can power modern living, economic opportunity, and environmental responsibility all on a single site.

Next Steps

The Company stressed that while negotiations are progressing, no definitive agreements have been executed at this time. However, management views the discussions as a catalyst that could drive substantial near-term growth opportunities, both for Green Rain Energy Holdings Inc. and its shareholders.

Green Rain Energy | https://greenrainenergy.com/

The solar industry's performance gap has long cost developers time, money, and credibility. GroundWork Renewables launches the STACK Framework, a five-layer methodology designed to remove uncertainty from the entire solar project lifecycle, from resource assessment to performance analytics.

The STACK Framework is the foundation of full-stack solar intelligence, a new category GroundWork is defining to close the industry's long-standing "certainty gap." By aligning measurement, validation, and analysis across every stage, STACK helps developers, EPCs, and asset owners reduce risk, pass capacity tests, and protect long-term asset value.

"Solar can't run on guesswork," said Ann Will, CEO of GroundWork Renewables. "With STACK, we turn solar performance into a science. Every decision is backed by proven data, so our clients can defend results, secure financing, and operate with certainty."

The five layers of the STACK Framework:

• Site Characterization – Start with truth, not assumptions
• Testing – Validate what matters before it fails
• Assurance & Accreditation – Trust your data. Prove your process
• Certainty Analysis – State the certainty. Get on the same page
• Key Performance Insights – Act with confidence. Plan with precision

By replacing disconnected tools and reactive troubleshooting with a proactive, lifecycle-spanning standard, the STACK Framework sets a new bar for operational excellence. It builds on GroundWork's 15+ years of expertise in MET data, PV module testing, and solar performance analytics — all backed by its ISO-certified processes.

The STACK Framework will make its public debut at RE+ 2025 in Las Vegas, September 8–11. Attendees can explore the methodology firsthand and see how certainty compounds across projects and portfolios. Visit GroundWork Renewables at RE+ Booth V7951 or learn more at grndwork.com.

GroundWork Renewables | https://grndwork.com/

Louth Callan, a leading power infrastructure construction firm, announced the mechanical completion of the Mousam River Solar Project, a 28-megawatt (MW) facility located in Sanford, Maine.

As the project's construction partner, Louth Callan delivered all site civil, structural, and electrical works. Mechanical completion confirms that all major construction activities are finalized, and the project is now transitioning to commissioning and energization.

"Mechanical completion of the Mousam River Solar Project demonstrates Louth Callan's ability to deliver complex power infrastructure on time and to the highest industry standards," said Nick Sylvestre, Managing Member of Louth Callan. "We are proud to contribute to the expansion of Maine's renewable generation capacity while reinforcing our reputation as a trusted partner in the delivery of large-scale power infrastructure."

In addition to advancing renewable energy projects like Mousam River, Louth Callan recently announced new divisions within the company expanding into the construction of traditional power facilities, transmission and substation work and geothermal plants. This strategic growth reflects the firm's commitment to providing end-to-end infrastructure solutions across diverse energy technologies, ensuring reliable power delivery while supporting the transition to a more sustainable and resilient grid.

The Mousam River Solar Project will soon begin producing clean, reliable electricity for thousands of homes and businesses across the region. Beyond its environmental benefits, the project generated significant local employment and subcontracting opportunities throughout the construction phase.

This achievement strengthens Louth Callan's position as a leader in the construction of utility-scale renewable and power infrastructure projects across the United States.

Louth Callan | https://louthcallan.com/

Aspen Power, a leading distributed generation platform dedicated to building the clean energy future, announced the closing of a new tax equity facility with Monarch Private Capital. The investment will support Aspen Power solar project portfolios across New York, Illinois, and Pennsylvania, further advancing the company’s 2025 pipeline.

With this latest transaction, Aspen Power has secured a total of $66 million in tax equity commitments during the first eight months of 2025, underscoring strong investor confidence in its distributed generation strategy.

“This commitment secured through Monarch strengthens Aspen’s ability to execute on our pipeline and expand access to distributed generation across multiple states,” said Bill DeLong, Chief Financial Officer at Aspen Power. “Tax equity partnerships like this are essential to driving long-term growth and accelerating progress toward a more sustainable future.”

"Partnering with Aspen Power enables us to advance projects that align with our 'all-of-the-above’ energy investment strategy," said Bryan Didier, Partner and Managing Director Energy at Monarch Private Capital. "This collaboration supports the energy transition across New York, Illinois, and Pennsylvania while delivering meaningful community impact and long-term value for our investors."

Aspen Power continues to lead in distributed generation, leveraging strong financial partnerships to bring more solar projects online. To date, the company has developed or acquired more than 600 renewable energy projects across 26 states, advancing its mission to build the clean energy future.

Aspen Power | aspenpower.com

Monarch Private Capital | https://www.monarchprivate.com/

Storion Energy LLC, a manufacturer of high-quality vanadium electrolyte and stack power assemblies, will demonstrate the benefits of their components for vanadium redox flow batteries (VRFB) during the RE+ 2025 conference, Sept. 8-11 at The Venetian Expo and Caesars Forum in Las Vegas. Storion Energy representatives will be available in Stryten Energy’s Booth #F18033 throughout the show.

Storion Energy, a joint venture between an affiliate of Stryten Energy LLC and Largo Clean Energy Corp., is removing the barriers to entry for battery manufacturers by enabling them to domestically source price-competitive components for flow batteries, including vanadium electrolyte. Storion combines access to high-quality vanadium supply from the largest producing vanadium mine in the Western Hemisphere with domestic electrolyte production to establish a fully integrated vertical supply chain for utility-scale VRFBs used in long-duration energy storage (LDES) applications.

“Rising energy demand, aging grid infrastructure, and fragile global supply chains are creating serious challenges for industries that depend on reliable power,” said Travis Torrey, CTO of Storion Energy. “Storion’s innovative vanadium electrolyte leasing model removes a major cost barrier, accelerating the adoption of vanadium flow battery technology for utility-scale storage. This is a critical step toward building greater energy resilience for businesses and communities across the country.”

Torrey will be a panelist in the “Making Solar More Bankable” discussion at the Stryten Energy booth on September 10 at 11 a.m. This panel discussion will examine how energy storage transforms solar into a grid-ready, financially viable solution. Along with Torrey, Olivia Amyette of Infinite Energy Advisors, Dr. Vick Singh of Dragonfly Energy, and Scott Childers of Stryten Energy will discuss how battery storage enhances solar reliability, reduces the levelized cost of energy, and supports sustainability goals. The conversation will also explore regulatory shifts, integration challenges, and the future of solar-plus-storage amid rising demand from AI, EVs, and electrification.

Visit Booth #F18033 to participate in Storion Energy’s panel discussion and learn how VRFB supports utility-scale LDES to ensure energy resilience and security.

Storion Energy | storion.com

PV Hardware USA (PVH USA), a global provider of solar tracking and foundation solutions, announced the opening of its second U.S. manufacturing facility in Houston. This milestone underscores the company’s commitment to strengthening domestic production capacity for solar energy facilities and meeting the ongoing demand for its products across North America.

The 95,000-square-foot facility expands PVH USA’s U.S. footprint, creating more than 100 jobs in the local community. Outfitted with state-of-the-art equipment, the new facility officially began operations in July and will significantly increase production efficiency while reducing lead times for customers. It joins the company’s first $30 million U.S. manufacturing facility, which opened in Houston in May 2024 as one of America’s largest solar tracker manufacturing facilities.

“Opening our second U.S. manufacturing facility represents an exciting step forward in our growth journey and demonstrates our commitment to the U.S. market,” said Rodolfo Bitar, VP of Business Development for PVH USA. “By expanding our presence in Houston, we are not only investing in local economic development but also ensuring we can better serve our customers with faster turnaround times and the highest quality products that are 100% domestically made.”

With the expansion, PVH USA continues to align its strategy with increased customer demand, supply chain resilience and developing solutions that help solar facilities upgrade and expand their capabilities. In recent months, the company has launched a series of innovative advancements that help solar facilities generate more energy during overcast weather, withstand extreme weather events and expand the types of terrain suitable for solar installations.  

Solar tracking technologies help to maximize solar power generation by automatically moving solar panels to follow the sun throughout the day, optimizing the angle at which panels receive solar radiation. Established in San Francisco in 2008, PVH has been at the forefront of innovation in solar tracking technology, developing systems and products that can adapt optimally to different terrains, inclinations, and climates. In addition, the company’s proprietary pre-assembly process can reduce installation times by 40%, which will be critical to rapidly expanding solar power capacity to meet increasing demand for electricity.

PV Hardware | https://pvhardware.com/