The Rise of Flat Plate Solar Thermal Collectors in China: From Niche Player to Building Integration Leader

The Rise of Flat Plate Solar Thermal Collectors in China: From Niche Player to Building Integration Leader

The application of flat plate solar thermal collectors in China boasts a history of over two decades, evolving through phases of copper-aluminum composite plates, ultrasonic strip welding, to today's advanced laser-welded full-plate technology. Although this technology, their market share remains around 10%, a stark contrast to the dominant evacuated tube collectors. meanwhile, their application is predominantly dealing in the warmer climatic regions of South and Southwest of China, a pattern that stands in sharp contrast to their widespread adoption in international markets. The primary reasons for this limited penetration are historical: the necessity for a glycol-based secondary loop system for freeze protection inherently led to higher costs, which significantly restricted their development in China's vast northern and inland regions.

Paradoxically, the utilization of solar thermal energy in China has seen lower adoption rates in more economically developed cities. Vacuum tube collectors found their stronghold in rural and suburban areas, where their perfect freezing resistance (via dry heating), low cost, and flexible installation fueled massive growth. However, the relentless urbanization of China, characterized by the proliferation of high-rise buildings, has exposed the limitations of traditional evacuated tube systems. Their challenges in meeting the demands of Building-Integrated Solar Thermal (BIST) systems—particularly regarding aesthetics, safety, and wind load resistance—have posed a critical new challenge for solar application in urban high-rises. Addressing system integration to ensure user demand has become an urgent priority.

This urban architectural evolution, coupled with the national government's escalating emphasis on building energy efficiency, is now creating a powerful tailwind for flat plate technology. Initiatives from the Ministry of Housing and Urban-Rural Development, such the Renewable Energy City Demonstration program and the Green Building Label assessment system, have provided significant policy impetus. Recognizing solar thermal as holding the greatest potential for building energy conservation, these measures have unlocked substantial opportunities for development. Here, flat plate collectors come into their own, offering inherent advantages in safety, high efficiency, pressure-bearing capability, and, most importantly, ease of architectural integration.

For high-rise buildings, flat plate collectors can be seamlessly incorporated through a variety of methods: embedded into walls or balconies, mounted as facade elements, installed as shading devices, or deployed as ground-mounted arrays. The use of a split-system, pressurized design with a glycol secondary loop is not a drawback in this context but a key strength, guaranteeing both the aesthetic integrity of the building and the system's safe and reliable operation. As living standards improve, a growing number of consumers are proactively requesting flat plate systems, a shift in demand reflected in the rapid increase of manufacturers specializing in them. This trend underscores the particular suitability of flat plate collectors for urban residential applications and points toward a promising future.

A testament to the technological advancement of domestic Chinese products is the 2010 Guangzhou Asian Games. This major international event, second only to the Olympics, outfitted its competition venues and athlete's village with flat plate solar water heating systems supplied by Guangdong Wuxing. Notably, the 2008 Beijing Olympics utilized German-made flat plate systems. This shift signifies the remarkable progress and rapid technological innovation achieved by Chinese manufacturers in a short period.

Looking beyond domestic hot water preparation—which represents only the most basic application of solar thermal energy—the flat plate collector platform is a springboard for innovation. By leveraging its core technologies, new products can be developed. For instance, utilizing its high-performance selective coating, optimized fin structure, and air flow channels, highly efficient solar air collectors can be engineered. These air collectors have vast application prospects in passive and active space heating and industrial/agricultural drying processes. Compared to vacuum tube air panels, the flat plate special ones offers lower flow resistance, higher efficiency, easier installation, and more reliable operation.

Similarly, building upon the laser welding used in flat plate collectors, companies can develop photovoltaic-thermal (PVT) hybrid systems. These products, such as PVT water heaters, solar-assisted heat pumps, and direct-expansion solar heat pumps, Meanwhile generate electricity and useful heat from the same surface area, maximizing the energy yield per square meter of roof space.

In a word, while solar water heating is an essential entry-level application, the future of solar energy lies in space heating, drying, power generation, lighting, cooling, and broader industrial heating. As national policies on renewable energy adoption, green building promotion, and renewable energy demonstration cities continue to deepen, the flat plate solar collector, with its unique set of advantages, is poised for rapid and great development, transitioning from a niche player to a central pillar of China's urban energy strategy.

In 2009, BTE Solar entered the flat-plate solar industry with its independently developed and manufactured PVD highly weather-resistant selective absorption coating.In 2010, BTE Solar compact modem manufacturing into the production of flat solar collectors, leading China's flat-panel solar industry into the modern production stage and achieving rapid development with a compound growth rate of 88% for 10 consecutive years. From 2021 to 2022, BTE flat-panel solar collector output ranked second in the world for two consecutive years.

At present, BTE has become the only company in the world that produces both "black coating-D-DOS"and "blue coating -PVD" for flat-panel solar energy, and has become a full industry chain manufacturer in the flat-panel solar thermal industry.

BTE Solar is dedicated to promoting the transformation of "solar hot water" to "flat plate clean thermal energy". Currently, its main products include regional distributed heating collectors, high-performance large-scale flat plate thermal energy collectors, flat plate air collectors, and DVC air collectors. It is also focusing on developing building heating and cooling systems, industrial heat systems, clean drying systems, PVT thermoelectric twin systems, and distributed energy stations. Regarding

Different applications of clean energy offer efficient and high-yield solutions.

Shengtaoke Group focuses on "flat panel cleaning energy" as its core, and possesses the technology for developing and applying multi-energy coupling systems such as solar energy, geothermal energy, and air energy.

The company provides comprehensive solutions in multiple fields for customers, including clean heating, clean hot water, heating for agricultural planting and breeding, agricultural drying, and industrial heating; meeting application needs such as residential heating and cooling, urban centralized heating, greenhouse constant temperature breeding,农副产品 drying, and industrial production heating.

It has rich engineering cases in municipal, real estate, new infrastructure, hotels, schools, hospitals, and farming and breeding sectors.

Case:

Solar energy centralized heating in Sakya Town, Shigatse City

Project Time: 2019

Project Scale: Heating Area 107,000㎡

The project selects the EFPC115 large flat-plate collector specifically designed for urban centralized heating for heating
With an area of 107,000 square meters, it has enabled urban residents to get rid of the reliance on burning cow dung and coal for food
A warm way. Reducing the combustion of standard coal by 2,424 tons annually is beneficial for protecting the local ecology
Great significance.