In 2025, rooftop solar installation systems are undergoing a historic transformation from “supplementary energy” to “core assets.” Driven by strong government policies, continuous technological breakthroughs, and accelerating market demand, rooftop photovoltaics (PV) have become the preferred pathway for industrial and commercial cost reduction, efficiency improvement, and green building transformation. From the curved roofs of steel plants to lightweight logistics warehouses, from integrated design in new factories to “retrofitting instead of repairing” old roofs, a rooftop PV revolution spanning urban and rural areas and reaching across the globe is unfolding in full force in 2025.

Policy Dividends: National Commitment to a “Rooftop Revolution,” Guided by a 50% Coverage Target

In 2025, the central government continues to strengthen policy support for rooftop PV. In its response to a proposal from the National People’s Congress, the Ministry of Housing and Urban-Rural Development explicitly stated that by 2025, the nation’s new building‑integrated solar PV capacity will reach at least 50 million kilowatts, and the rooftop PV coverage rate for new public buildings and new factory buildings will aim to reach 50%. This binding target has injected strong policy momentum into the 2025 rooftop PV market.

In its response issued in August 2025, the National Energy Administration further emphasized that it will actively conduct surveys of building rooftop PV resources, improve relevant building PV standards, promote technological and business model innovations, and continue to strongly support the development of building‑integrated PV in the revision of the Renewable Energy Law. In March 2025, the National Energy Administration issued the Notice on Further Organizing and Implementing the “Thousand Towns and Villages Solar Initiative,” setting forth clear requirements for advancing the development and utilization of distributed PV in rural areas. In June, the National Development and Reform Commission, the Ministry of Industry and Information Technology, and the National Energy Administration jointly issued the Notice on Carrying Out the Construction of Zero‑Carbon Industrial Parks, supporting qualified regions in taking the lead in establishing a number of zero‑carbon industrial parks.

The concentrated release of these policies provides a solid institutional foundation for the large‑scale development of rooftop solar installation systems in 2025.

Technological Breakthroughs: From a “Safety vs. Returns” Dilemma to a Triple Upgrade in “Protection + Power Generation + Aesthetics”

In 2025, rooftop PV technology has achieved qualitative leaps. At the BAU China International Building Technology Expo held in November, LONGi Solar showcased its building‑friendly rooftop PV series, vividly demonstrating the breakthrough from the previous “safety vs. returns” choice for industrial and commercial rooftop PV to a “triple upgrade in protection, power generation, and aesthetics.”

The exhibited LONGi Hi ROOF S features an innovative “high‑efficiency module + non‑penetrating rail bonding” design. Compared to traditional point‑clamp fixtures, which can cause localized stress concentration on the roof and lead to deformation and cracking, this design evenly distributes the load from the PV modules to the roof’s load‑bearing structure, achieving a shift from “rigid fastening” to “elastic integration” between the PV system and the roof. LONGi Top 5, powered by HPBC 2.0 cells, incorporates an innovative weak‑conduction design that effectively prevents fire risks caused by localized overheating and can withstand super‑typhoons of up to Category 17, truly delivering a dual guarantee of “safety and power generation.”

Addressing the industry challenge of lightweight roofs, GoodWe announced in November 2025 that its Galaxy lightweight modules had been successfully installed on the factory roof of the Zehnder Group in Switzerland. The project utilizes frameless lightweight modules and a non‑penetrating adhesive installation process, with modules weighing only 5.6 kg/m², perfectly resolving the issue of insufficient load‑bearing capacity on lightweight roofs. The 450 kWp system consists of approximately 12,000 modules, with an average installation time of just 3–4 minutes per module, demonstrating the principle of “lightweight equals high efficiency.”

In terms of architectural aesthetics, the world’s first Top 5 system equipped with HPBC 2.0 cells, with its integrated PV and roofing design, has helped create a “green landmark” in the Boao Zero‑Carbon Park project. Meanwhile, LONGi Loong Jin 3, described as a “colorful building material that generates electricity,” can be customized in various colors and finishes, achieving the artistic integration of “architecture and PV” in landmark projects such as the Beijing Workers’ Stadium and the Shenzhen Convention and Exhibition Center.

Benchmark Projects: From a 40‑Day “PV Speed” to the World’s Largest Single Rooftop Solar Power Station

In 2025, rooftop solar installation projects have broken new ground in both scale and efficiency. In early December, the second phase of the LONGi Leye building‑integrated PV project in Xi’an was successfully connected to the grid, with a total installed capacity of 3.3 MW. From project initiation to full‑capacity grid connection, construction was completed in just 40 days, injecting strong momentum into regional green and low‑carbon development with this “PV speed.”

The project uses the LONGi Hi ROOF S system, which, through a highly integrated modular design, reduces the variety of construction materials by approximately 70%. Semi‑automated adhesive‑application robots precisely follow preset paths and process standards, improving overall construction efficiency by about 30% compared to traditional approaches. Over its entire lifecycle, the project is expected to generate approximately 89.6571 million kWh of electricity, equivalent to saving about 27,729 tons of standard coal, with emission reductions comparable to planting approximately 191,408 trees.

Also in November, the 2.4 MW rooftop PV project at the CNBM Junxin headquarters in Jiangyin was successfully connected to the grid. The project uses self‑developed 700W heterojunction (HJT) high‑efficiency modules. Although some parts of the roof were over 20 years old, the project team precisely developed a reinforcement plan and completed the entire process from filing to full‑capacity grid connection in just 35 days.

On the international stage, in November 2025, Bahrain announced the construction of the world’s largest single rooftop solar power station, with a capacity of 50 MWp. The system is installed on a 262,000‑square‑meter new covered stockyard at Bahrain Steel. The entire project encompasses 14 sites with a total installed capacity of 123 MWp, expected to generate 200 million kWh of electricity in its first year and reduce carbon emissions by 90,000 tons. This project marks the growing global influence of Chinese PV technology and construction capabilities.

Application Breakthroughs: The “Low‑Carbon Value‑Add” Revolution on Steel Plant Roofs

In 2025, rooftop solar installation systems have achieved large‑scale application in energy‑intensive industries such as steel manufacturing. LONGi Green Energy, in partnership with Century 3, has combined PV technology with building technology, enabling more steel plant roofs to be transformed into power stations.

The new hot rolling mill project at Baowu Taigang incorporated the LONGi Century 3 Top system from the initial design phase, with PV modules deeply integrated into the roof structure, eliminating the need for later retrofitting. Over its lifecycle, the project will reduce carbon emissions by approximately 240,000 tons. At the Baowu Xinyu Steel silicon steel plant, some older roofs were retrofitted with the Top system. Using non‑penetrating connection technology to fundamentally prevent leaks, the system generates 55.5 million kWh of electricity annually over its lifecycle, turning what was once a cost‑incurring old roof into a “green asset” that continuously generates returns.

Curved roofs, due to their large curvature and complex stress characteristics, have long been considered “forbidden zones” for PV installation. The Shaanxi Longmen Iron & Steel and Jiangsu Changqiang Steel projects have broken this perception, adopting a “follow‑the‑slope” installation approach that perfectly fits the PV system to the curved roof. Over their lifecycles, these two projects are expected to generate 227 million kWh and 445 million kWh, respectively. Addressing the issue of dust generated in steel production, the LONGi Century 3 PV system is equipped with an anti‑soiling design, allowing rainwater to naturally “self‑clean” the surface, resulting in 6% higher power generation compared to traditional products.