Flat Plate Split Solar Water Heater Systems: A Rising Star in the Global Renewable Energy Market

Introduction: A New Wave in Water Heating

As the world accelerates its transition to clean energy, a unique technology is gradually emerging in developed countries and emerging markets: BTE flat plate solar water heaters. This kind of device was often overshadowed by electric water heaters and gas water heaters in the past, but now it is increasingly regarded by more and more households, commercial institutions and public facilities as an innovative solution to reduce energy costs while moving towards carbon neutrality. 

This article, based on the viewpoints of industry experts, the latest market data, and feedback from end users, provides an in-depth interpretation of the working principle, technical structure, application difficulties, advantages, and typical applications of flat-plate solar water heaters.

What is a flat-plate solar water heater? 

Flat-plate solar water heaters are renewable energy devices that heat water by using solar radiation. It mainly consists of two core parts:

1. Flat-plate collectors - usually installed on rooftops or in open areas, they collect energy by absorbing solar energy and converting it into heat. Its structure is generally composed of a dark absorption layer, a transparent cover plate, an insulation layer and a metal casing, thereby achieving efficient heat capture.

2.  Independent water Storage Tank- Unlike compact integrated devices, the water storage tank of a split system is usually placed separately indoors or on the ground. This not only reduces the load on the roof but also prevents the water storage tank from being directly exposed to bad weather and getting damaged. 

The operating principle of the system is based on heat transfer: The circulating fluid (water or antifreeze) absorbs energy in the collector and then transfers the heat to the well-insulated water storage tank to provide domestic hot water.

Scientific design of flat plate collectors

Flat-plate collectors are renowned for their high efficiency and durability. Their key structures include:

1. Absorption layer : The surface is coated with a selective coating to absorb solar radiation to the greatest extent and minimize heat loss.

2. Transparent cover plate: The glass or polymer covering layer can effectively reduce energy loss caused by convection and radiation.

3. Insulating material : Reduces heat leakage from the back and sides.

4. Piping system: Copper or aluminum pipes are usually used to transport the heated fluid to the water storage tank.

Under normal operation, this system can heat water to 60-80°C (140-176°F), and even in moderate sunlight conditions, it can meet the daily hot water demand, with a very wide range of applications.

The shortcomings of traditional water heaters

To understand the advantages of solar water heaters, it is necessary to first recognize the drawbacks of traditional heating methods 

1. High operating costs  - Electric water heaters and gas water heaters often account for the majority of a household's monthly energy expenditure. In some areas, the consumption of hot water supply can reach 30% of the total household energy consumption.

2. Reliance on limited resources - Gas water heaters are highly dependent on fossil fuels and are significantly affected by price fluctuations and international situations.

3.  Severe carbon emissions  - Traditional heating methods produce a large amount of carbon dioxide and are an important driver of climate change.

4. Limited service life - Many electric water heaters will be scrapped within 5 to 7 years due to corrosion, scaling or reduced energy efficiency.

Split-plate solar water heaters directly address these pain points and offer a more long-lasting and environmentally friendly alternative.

The core advantage of the flat-panel split system 

1. Energy conservation  - Depending on local sunlight conditions, users can reduce their hot water expenses by 50% to 80% annually.

2. Reduce carbon emissions - Each set of equipment can offset 1 to 3 tons of carbon dioxide emissions annually, making it highly suitable for environmentally conscious consumers.

3. Robust structure - Compared with vacuum tube systems, flat plate collectors have fewer components and are more capable of withstanding harsh weather conditions such as wind and hail.

4. Flexible installation - The water storage tank is no longer fixed to the roof, which not only reduces the load on the building but also enables a more aesthetically pleasing design.

5.  Policy Support  - In many countries, users installing solar water heating systems can enjoy tax benefits, subsidies or green certifications.

Market development trend 

The solar water heater industry is expanding rapidly. According to the latest statistics from the International Energy Agency (IEA), by 2023, the cumulative installed capacity of global solar thermal systems has exceeded 500 gigawatts (GWth), with flat-plate products accounting for a significant share. 

Europe remains the largest application market. Against the backdrop of rising energy prices and increasingly severe climate issues, flat-plate solar water heaters are gradually being regarded as a "long-term and stable investment". It can not only help users reduce their energy bills in the short term, but also continue to have a positive impact on society and the environment in the coming decades.

BTE Company Profile:

Soletks Group-BTE is a high-tech industrial group with a complete industrial chain of comprehensive solar energy utilization solutions. In recent years, it has vigorously developed clean energy alternative business based on solar energy. Its subsidiaries include Dezhou Jinheng New Energy Co., Ltd., Shandong Feitian New Energy Co., Ltd., Shandong Soletks Solar Technology Co., Ltd., Dezhou BTE Co., Ltd., Shandong Shenggao Thermal Power Co., Ltd., and Dezhou Jinnaier New Material Technology Co., Ltd. , Zhongye Energy (Beijing) Co., Ltd., Tibet Soletks Energy Technology Co., Ltd., etc. With the help of specialization and technology, Soletks Group has achieved a continuous compound growth rate of 88% in the past 10 years and an increase of 192 times. Soletks Group has established its own advantages in core technology research and development, brand, market, team, management, etc. It has sales and service channels covering the global market, and its products are exported to many countries and regions. The annual output of flat-panel solar collectors is 3GWt (600,000 square meters), ranking the third in the world for three consecutive years from 2017 to 2019, and the second in the world from 2020 to 2021.

BTE has always regarded technological innovation as the core competitiveness of the enterprise. It has 4 technical departments, 1 research institute, and 1 laboratory. The scientific research personnel account for 16%, of which 50% have been in the industry for more than 20 years. In conjunction with the Chinese Academy of Sciences, Tsinghua University, Beijing University of Technology, Shandong Jianzhu University and other research and development institutions, Soletks Group vigorously develop products that convert solar "hot water" to solar "thermal energy", and successfully develop urban heating collectors and distributed heating collectors, flat plate air collector, double tube air collector; Tobacco drying collectors, industrial heat collectors, and complete sets of equipment for distributed energy stations are being developed. Soletks Group develops system solutions in new applications of clean energy, explore high-quality market space, and gains market share in a huge market scale. Soletks Group has 29 world-leading patented technologies and industry solutions. With industry-leading technical reserves and R&D strength, advanced manufacturing capabilities of Industry 4.0, and a complete after-sales service system, it leads the industry to transform from solar "hot water" to "thermal energy", providing high-quality thermal energy, heating, cooling, heating and other clean energy comprehensive utilization services for civil buildings, military facilities, industry heating, planting, breeding, drying and other fields. The group has been approved as a national high-tech enterprise, the title of "Leader" of National Solar Thermal Utilization Products, a "Little Giant" of National Specialized and New Enterprise, "Specialized and New" Enterprise of Shandong Province, Shandong Enterprise Technology Center, Gazelle Enterprise of Shandong Province and other platforms and honors.  

BTE is an innovative organization with a technology research and development center, responsible for vacuum coating system design, film design, collector design, solar building integrated design and other research and development work. Master and flexibly use advanced innovative methods and skills, participate in international market innovation competition, and cultivate R&D teams. With the aid of the R&D resources of the Chinese Academy of Sciences, applied mathematics and physics knowledge for systematic development, developed a number of CAE (finite element) engineering examples, used CAE methods to solve technical problems in actual R&D work, and analyzed actual physics with mathematical methods problem. For example, using mechanical finite element analysis of mechanical structure, fluid finite element analysis of atmosphere distribution in vacuum sputtering system, magnetic field finite element analysis of target (sputter source/cathode) structure, optical finite element analysis of film structure, Heat transfer finite element analysis of the thermal efficiency of the collector. The research and development work has been disruptively innovative, the research and development cycle is shortened, and the research and development cost is reduced. In terms of process development, equipment development, and product development, the product design intent can be realized.

The company has the experience and ability to independently design, manufacture and integrate large-scale magnetron sputtering solar selective cermet coating production lines with the same technological level as developed countries in the world. It also has Know-How that designs and prepares composite coatings composed of materials of different thicknesses and different compositions in the nanometer scale to achieve selective absorption, transmission and reflection of various bands of spectrum.

The influence of the flow velocity of the working fluid in the collector flow channel on the flow

BTE practices the "craftsman spirit", strives for perfection, learns constantly, thinks and innovates. From the perspective of resource integration and sustainable economic development, it aims to build a global excellent clean energy intelligent manufacturing base. Through our products and services, we will contribute to the brighter sun, fresher air, and protect the lucid waters and lush mountains, and make contribution to the carbon peak in 2030 and carbon neutrality in 2060!