A Record That Surpasses Its Korean Predecessor

The previous world-record solar cell efficiency of 26.3% for perovskite/CIGS tandem configurations was set just a year earlier by a joint research team from Seoul National University and the Korea Institute of Science and Technology (KIST). The fact that this benchmark has now been surpassed by another Korean research institution — KIER — reinforces the country’s leading position in next-generation thin-film solar cell technology.

Silicon solar cells, which currently dominate the global photovoltaics market, have reached a stage of technological maturity. Fundamental physical limitations now leave little room for meaningful efficiency gains within that technology. Against this backdrop, tandem solar cells are emerging as a compelling next-generation solution for high-efficiency photovoltaics.

The tandem approach works by stacking multiple solar cells, each with different absorption characteristics, to capture a broader range of sunlight wavelengths simultaneously. This multi-layer structure allows for considerably higher energy conversion than any single-junction cell can achieve on its own.

The perovskite/CIGS tandem solar cells developed by the KIER research team are configured with a perovskite cell at the top and a CIGS cell at the bottom. This design enables the two cells to absorb different wavelengths of sunlight at the same time. Since both perovskite and CIGS materials are well-suited for thin-film processing, the technology combines high efficiency with the practical advantages of light weight and structural flexibility.

However, integrating the two cell types introduces its own engineering challenges. The assembly process can potentially degrade the perovskite light-absorbing layer, while certain cell layers may absorb unwanted light, ultimately reducing overall efficiency.

To overcome these obstacles, the KIER research team undertook a comprehensive analysis of the root causes behind efficiency losses. This led to the development of an advanced interfacial layer material and processing technology specifically designed to protect the perovskite layer from potential damage during integration.

The team also optimized the structure of the top transparent electrode and charge transport layer to minimize undesired light absorption and prevent photocurrent loss. This dual-focus approach resulted in a laboratory-measured efficiency of 27% and the officially certified Fraunhofer ISE figure of 26.7%.

Broad Application Potential Across Industries

The developed technology is expected to increase electricity generation per unit area, expanding the potential applications of photovoltaic power generation considerably. The lightweight and flexible thin-film design makes perovskite solar cell systems promising candidates for deployment not only in buildings and automobiles but also as power sources for small satellites and space-based data centers — future applications where weight and space constraints are particularly critical.

Inyoung Jeong, a senior researcher at KIER who led the research, stated: “This achievement is significant in that both cell efficiency and stability can be enhanced by minimizing potential interfacial and optical losses during the integration of perovskite and CIGS. The resulting efficiency was also officially certified by a world-renowned institute and recognized as a world-record performance, underscoring Korea’s technological competitiveness.”

Looking ahead, the KIER research team will focus on scaling the technology so that large-area modules achieve efficiency levels comparable to those demonstrated in the small-area laboratory devices developed during this study. The team plans to collaborate with industry partners interested in mass production and commercialization, with active pursuit of technology transfer as a priority.

Over the longer term, the research program aims to expand into next-generation space solar cells — leveraging the high efficiency and low weight of tandem solar cells to enable reliable energy generation in space environments.

The research utilized a Suntech STP200-18/Ub module containing 54 polycrystalline silicon cells based on an aluminum back-surface field (Al-BSF) architecture. Following the removal of the junction box and aluminum frame, the team separated the glass from the laminate using a hot knife and milled the material at various speeds to assess the impact on impurity removal. The study determined that milling at 400 rpm was optimal for preventing particle agglomeration, which significantly improved the subsequent removal of metallic impurities. A two-stage purification process followed, involving 36 wt% hydrochloric acid (HCl) to remove aluminum, copper, tin, and lead, and 36 wt% nitric acid (HNO₃) to dissolve silver.

Optimization of Purification and Nitridation Processes

To address acid-resistant titanium dioxide (TiO₂) originating from the module backsheet, the researchers implemented a sedimentation process. By dispersing the powder in water and allowing it to settle for five minutes, they were able to remove 71.4% of TiO₂ impurities while maintaining a silicon recovery rate of 92.3%. The resulting high-purity powder was then nitrided under a flow of 95% nitrogen and 5% hydrogen at temperatures up to 1,450 C. This precisely controlled environment led to a final product containing 93.1% α-Si₃N₄, a significant improvement over the 54.7% α-phase proportion achieved without the additional purification steps. The findings demonstrate that controlling impurities from waste PV modules directly influences the structural properties of the final recycled silicon nitride.

Scalability and Environmental Impact

The research team is now working to transition from proof-of-concept toward a scalable, mobile recycling technology in collaboration with Wonkwang S&T, a Korean PV recycling firm. This mobile approach is designed to process EoL modules closer to their generation sites, potentially reducing transportation costs by approximately 30% and lowering carbon emissions by more than 10% compared to centralized recycling facilities. “To the best of our knowledge, this is the first demonstration of converting silicon recovered from actual EoL PV modules into Si₃N₄,” stated corresponding author Jin-Seok Lee. The complete findings of the study, titled “Upcycling silicon recovered from photovoltaic waste into silicon nitride via the field-applicable control of metal and ceramic impurities,” have been published in Materials Today Sustainability.

The move supports Namibia’s strategic efforts to enhance domestic electricity generation and decrease its reliance on power imported from neighboring countries. By leveraging the country’s high levels of year-round sunlight, expanding decentralized generation is expected to improve national energy security and build a more resilient electricity system. For consumers, the adoption of small-scale solar and storage can lower monthly power costs and provide essential backup power during grid outages. Additionally, eligible participants may continue to utilize existing net-metering arrangements to feed surplus electricity back into the local network, further supporting the economic viability of these installations.

While the simplified framework covers a wide range of residential, agricultural, and small-to-medium commercial projects below the 500 kW threshold, developers must still comply with all applicable technical and safety requirements. Electricity distributors will remain responsible for assessing grid capacity and technical conditions prior to connecting new generation systems. Overall, the ECB’s reforms are anticipated to drive growth in the distributed renewable energy market, potentially creating employment opportunities while advancing Namibia’s clean energy transition through accelerated decentralized solar deployment across the nation.

Comprehensive Equipment Scope and Vertical Integration

The proposed financial commitment comprises US$1.5 billion in real property alongside US$8.6 billion in manufacturing equipment and other personal property. Filing documents submitted under the Chapter 312 tax application outline an operation spanning the entire silicon-to-module value chain to achieve full vertical integration. Equipment detailed in the filing covers ingot manufacturing, wafer slicing, chemical coating, metallisation and printing, cell testing and quality control, automated material handling, and cleanroom systems. This equipment scale supports high-volume automated wafer and cell manufacturing rather than solely a downstream module assembly facility. The campus plans also incorporate chemical storage and delivery systems, utility infrastructure, and environmental and safety systems.

Employment Projections and Tax Limitation Framework

To support the development, Tesla is seeking a 10-year property tax limitation under the Texas Jobs, Energy, Technology and Innovation Act. Once fully operational, the solar manufacturing campus is projected to create 9,712 permanent full-time jobs alongside 1,147 local construction jobs. Construction is scheduled to run from 2026 through 2028, with commercial production targeted to begin in the first quarter of 2029.

Although the filing does not disclose an annual nameplate manufacturing capacity, industry analysts note the massive scale of the facility. Commenting on the investment, Joe Hennessy, market research analyst at PV Tech Research, said, “This is a massive investment in US manufacturing, as big as we’ve ever seen for one site. Qcells’s facility at Cartersville cost around US$2.5 billion for 3.3GW of integrated PERC capacity, suggesting this facility could have a capacity of more than 10GW on a single site.”

Evolving Trade Landscape and Supply Chain Dynamics

The proposed development aligns with broader trends across the domestic solar market. Hennessy added: “This year, many suppliers have aimed for vertical integration in the US. This is due to the many barriers imports must go through the antidumping and countervailing duty (AD/CVD) and the new Section 232 regulations, starting in December. This will likely start a trend of even more upstream investment, now that those have been announced.”

US solar manufacturers currently navigate a complex trade environment, with the US Department of Commerce pursuing AD/CVD cases covering imports from India, Indonesia, and Laos. Regulators have also been asked to investigate alleged circumvention involving Ethiopian solar cells produced by Toyo Solar and Origin Solar using Chinese-origin components, as well as cell imports from South Korea involving Hanwha and other producers. Furthermore, US President Donald Trump introduced a 15% tariff on imports of products using polysilicon and set minimum prices for polysilicon and its derivatives under Section 232 of the Trade Expansion Act of 1962, effective 4 December 2026. Moustafa Ramadan, head of market research at PV Tech Research, described the move as “one of the biggest events in the US solar landscape.” This major manufacturing investment addresses these evolving conditions by establishing domestic end-to-end production.

Engineering Ordered Molecular Alignment for Enhanced Efficiency

Perovskite photovoltaics have drawn widespread attention as a next-generation technology because of their high photoelectric conversion efficiency, which represents the rate at which light is converted into electricity. For a device to achieve high efficiency, charge carriers generated in the light-absorbing layer must flow smoothly into the charge transport layer. When the device area is enlarged, however, the condition of the interface where the two layers meet varies by location, causing uneven charge transfer and a resulting drop in efficiency.

Conventional interface treatment techniques introduce organic molecules onto the perovskite surface to reduce surface defects that cause charge loss. When those molecules are arranged irregularly, though, they can impede charge movement and create additional losses at the interface. Going beyond the conventional focus on reducing interface defects, the research team engineered an interface structure in which the molecules are arranged in an orderly fashion, enabling more uniform charge transfer across the interface.

Verified Large-Area Module Performance and Stability

Applying this interface design principle to actual devices, the team achieved a certified photoelectric conversion efficiency of 26.94% in a small-area cell and 23.21% in a large-area cell with an active area of 25 square centimeters. The 25-square-centimeter large-area module was fabricated in a monolithic structure connecting 10 solar cells in series, and its performance was verified through independent certification. This demonstrates that the team’s interface design is effective not only in small-area devices but also in large-area modules.

In long-term stability tests, the cells retained more than 93% of their initial efficiency after 1,000 hours at 85 degrees Celsius, and maintained 85% of their initial efficiency after 1,800 hours under continuous illumination at an intensity comparable to actual sunlight.

Commercialization Prospects and Future Applications

The researchers expect that combining the molecular design principle with mass-production technologies such as continuous manufacturing processes could expand the application of these devices into key sector areas:

• Building-integrated photovoltaics
• Lightweight and flexible solar cells
• Mobile power sources

“Achieving high perovskite solar cell efficiency at large area is a challenge that must be solved for commercialization,” Lee said. “We hope the molecular design principle presented here will serve as a foundational technology that reduces interface losses during scale-up and accelerates the commercialization of perovskite solar cells.”

The findings were published in Advanced Materials, an international journal in the field of materials science.

Effective December 4, 2026, the MIP program establishes mandatory pricing floors for goods entered for consumption or withdrawn from a warehouse. The proclamation sets the MIP for raw polysilicon at $21 per kilogram, while polysilicon ingots and wafers are set at $100 per kilogram. Downstream solar components are also covered, with solar cells required to meet a minimum price of $0.22 per watt and solar modules set at $0.38 per watt. Under these polysilicon import regulations, importers must provide documentation certifying that the first arm’s-length U.S. sale occurs at or above the relevant MIP. Failure to provide such documentation will result in a specific tariff equal to the applicable MIP, while entered values below the threshold will trigger a tariff equal to the price difference.

Ad Valorem Duties and International Alignment

In conjunction with the pricing floors, the proclamation imposes an additional 15% ad valorem duty on imports of polysilicon ingots and specified derivatives starting December 4, 2026. This duty generally applies in addition to existing taxes, fees, and charges. However, the proclamation includes specific provisions for key trading partners to ensure total duty rates remain aligned with strategic objectives. For imports originating from Japan, Korea, Taiwan, Switzerland, Liechtenstein, or European Union member countries, the combined Section 232 tariff and the applicable Column 1 duty rate will equal 15%. Imports from the United Kingdom will be subject to a 10% additional duty. The Secretary of Commerce maintains the authority to adjust MIPs periodically to reflect nondistorted market conditions and fair market values.

Onshoring Incentives and Investment Programs

To support the growth of a domestic manufacturing base, the proclamation authorizes the Secretary of Commerce to establish an investment incentive program. This program is open to companies producing raw polysilicon, ingots, wafers, and solar cells within the United States. Participating firms must submit an onshoring plan that includes a commitment to build, refurbish, or expand domestic facilities, with construction mandated to begin by January 20, 2029. If a plan is approved, the company may be permitted to import necessary production equipment and covered products without paying the newly established Section 232 duties.

The volume of duty-free imports permitted under this program will be commensurate with the scale of the company’s committed investment. These benefits are strictly tied to the facility’s construction period and remain contingent on meeting progress milestones under the approved plan. The Department of Commerce will provide continuous monitoring and enforcement to ensure that the incentives directly contribute to the expansion of U.S. polysilicon production capacity. This dual approach of protective trade barriers and aggressive investment incentives aims to decouple the U.S. solar industry from volatile global markets while reinforcing the national security of the energy transition.

Koji Tanaka, an associate professor at the Japan Aerospace Exploration Agency, stated that the primary objective of the project is to demonstrate the fundamental systems required for a future large-scale solar power station. Under this conceptual framework, specialized equipment would collect sunlight in orbit, convert it into electrical energy, and utilize wireless power transmission to deliver that energy to specific receiving stations located on the ground.

Technical Precision in Wireless Power Transmission

A distinct advantage of this space-based solar power system is its potential flexibility. Unlike traditional ground-based solar arrays that are fixed in one location, a satellite-based system could theoretically redirect its energy beam to various receiving sites, provided they are equipped with the necessary charging infrastructure. However, achieving the required accuracy for such a beam remains a formidable engineering hurdle.

Tanaka noted that the precision required is equivalent to hitting a target only 3 centimeters wide from a distance of 1 kilometer. To address this, researchers are leveraging phased-array antenna technology. This method, which allows for the electronic control of radio wave direction, is already utilized in radar systems and is being adapted to ensure the energy beam remains locked onto its terrestrial target. This satellite experiment will be crucial in determining if such high-level precision can be maintained in the harsh environment of space.

Evaluating Environmental and Atmospheric Impacts

Beyond the mechanical alignment of the beam, the research team must also account for how the Earth’s atmosphere and the space environment interact with the energy transmission. A key component of the upcoming study involves observing how ionospheric plasma might influence the stability and efficiency of the beam. Tanaka emphasized that the project must thoroughly evaluate the reciprocal effects between the transmission technology and its surroundings before any commercial application can be considered.

The construction of the flight model marks a transition from theoretical research to practical testing. The data gathered from this mission will provide essential insights into beam control and transmission accuracy, helping to define the future of space solar power technology. As the project moves toward launch, the results will help determine the commercial viability of a permanent solar power station in orbit.

The Path Toward Commercial Implementation

While the engineering milestones are critical, the broader implementation of space-based solar power faces non-technical requirements. Establishing international frameworks to govern orbital activities and securing consistent, long-term development funding are essential steps for the industry. Japan’s role in this emerging sector of renewable energy innovation will depend on continued technical success, international cooperation, and the ability to attract the investment necessary for large-scale deployment.

Strategic Financing and Global Partnerships

The extensive banking consortium involved in this financial close includes Abu Dhabi Commercial Bank, Abu Dhabi Islamic Bank, BNP Paribas, Bank of China, and Credit Agricole Corporate and Investment Bank. Additional support was provided by Dubai Islamic Bank, First Abu Dhabi Bank, HSBC, KfW IPEX-Bank, Natixis, Sumitomo Mitsui Banking Corporation, Standard Chartered Bank, and Societe Generale. By coordinating this large-scale consortium, Masdar has demonstrated its capacity to attract significant international investment for critical green infrastructure.

Mazin Khan, the Chief Financial Officer of Masdar, highlighted the importance of this achievement, stating that the successful financial close demonstrates the company’s ability to mobilize global capital for large scale renewable energy infrastructure while supporting long term economic growth and energy security. He further emphasized that the organization is prepared to move forward with the Abu Dhabi Solar Project to deliver “reliable, affordable and clean electricity around the clock.”

Technical Specifications and Operational Timeline

The Abu Dhabi Solar Project is designed to combine 5.2 GW of solar photovoltaic capacity with a 19 GWh battery energy storage system. This integration will allow the facility to supply 1 GW of continuous renewable power, effectively enabling round-the-clock clean electricity generation. Construction activities for the site began in October 2025, and the project is currently on track to reach commercial operations by 2027. To ensure high-quality execution, Sungrow and BYD have been appointed to supply the battery energy storage systems, while JinkoSolar and JA Solar will serve as the preferred module suppliers, each contributing 2.6 GW of solar modules.

This development is a vital component of Masdar’s expanding global renewable energy portfolio, which currently exceeds 65 GW across various sectors including wind and battery storage. The successful advancement of this project supports the company’s strategic objective to increase its total renewable energy capacity to 100 GW by the end of the decade.

Impact of Economic Pressures on Renewable Energy

This record-breaking demand for electricity in the United States is being propelled by the expansion of data centers and the ongoing electrification of various sectors, including transportation. Such growth has intensified the requirement for new generating capacity while concurrently driving up capital costs. According to Lazard’s findings, the levelized cost—representing the average expense of producing a unit of electricity over a power plant’s operational lifespan—for utility-scale solar has climbed to a range of $40-$98 per megawatt hour, up from the previous year’s range of $38-$92 per MWh. The firm noted that data centers are a primary driver of this capacity need, which in turn impacts the overall capital costs of development.

Factors Driving the Increase in Development Expenses

Samuel Scroggins, who serves as the head of renewables and sustainable infrastructure at the firm, noted that the levelized Solar Power Costs, along with storage costs, have risen due to several influential factors. These include elevated interest rates and inflationary pressures stemming from tariff pass-throughs. Additionally, the repricing of supply chains as they transition away from China toward other regions, such as Southeast Asia, has contributed to the upward trend. Even with these shifts, renewable energy options like onshore wind remain a primary choice for new capacity. Onshore wind costs also saw an increase, moving to a range of $37-$99 per MWh from the prior $37-$86 per MWh.

The report emphasizes that even when factoring in the expenses required to back up intermittent renewable energy to maintain grid reliability, solar and wind projects remain broadly competitive against new gas-fired options. This highlights the significant role that renewable energy is expected to play in addressing the nation’s rising power needs while maintaining grid reliability. Meanwhile, the levelized cost for electricity generation over a plant’s operational lifespan for combined-cycle natural gas plants rose to between $51 and $129 per MWh. These natural gas plants remain a functional choice for utilities and developers due to their consistent power output, even as the industry navigates a complex landscape of Solar Power Costs.

Financial Framework and Market Mechanism

The financial framework for these auctions maintains the established ceiling price of €0.055 ($0.063) per kWh, consistent with previous YEKA rounds. This ceiling price serves as the upper limit for all participating bidders to ensure competitive energy costs. For the solar projects, the floor price is fixed at €0.0325 per kWh, while the wind energy tenders carry a floor price of €0.0350 per kWh. In instances where the floor price is reached, the competition will transition into a contribution-based model with a minimum starting increment of €10,000 per MW. Winners of the Türkiye solar tenders will benefit from a free market sales window of 60 months, whereas wind projects will receive 72 months. Upon the conclusion of this period, a 20-year power purchase agreement based on the secured tender price will take effect, providing long-term revenue certainty for developers.

Regional Distribution and Strategic Energy Targets

Geographically, the 14 solar developments are distributed across several provinces, including Ankara, Batman, Denizli, Konya, Malatya, Mardin, Diyarbakır, Elazığ, and Kahramanmaraş. Individual project capacities vary from 25 MW to 230 MW. Notable installations include a 230 MW plant in Ankara, a 200 MW facility in Diyarbakır, a 140 MW site in Ankara, and a 110 MW project in Konya. Minister Alparslan Bayraktar emphasized that the Ministry for Energy intends to maintain a consistent procurement schedule of at least 2 GW annually. This procurement schedule supports the national objective of reaching 120 GW of combined solar and wind capacity by 2035. Currently, the nation’s renewable energy capacity is approximately 78 GW, with solar power having exceeded 26.7 GW as of late April. The first round of tenders under this auction mechanism took place early last year, allocating 800 MW of solar and 1.2 GW of wind capacity.