Flat panel solar water heaters are the earliest solar thermal utilization products to enter Chinese households. Due to cost and effectiveness constraints, flat solar water heaters are gradually being replaced by vacuum tube solar water heaters and have become marginal products in the Chinese market. In recent years, with the changing market demand and the trend towards building integration, the advantages of flat plate collectors such as pressure bearing operation and ease of integration have been fully utilized. Under the background of policy guidance and technological progress, flat panel solar water heaters may usher in new development opportunities. 
New opportunities for solar water heaters 
Promoting the construction of ecological civilization is one of the basic goals of China's economic and social development in the coming years. The utilization of renewable energy, as an important measure of ecological civilization construction, has been actively promoted by government departments at all levels. Solar thermal utilization technology is currently the most widely used and economically competitive renewable energy utilization technology compared to conventional energy sources. On May 10, 2013, the Ministry of Industry and Information Technology issued the "Guiding Opinions on Promoting the Healthy Development of the Solar Water Heater Industry", proposing to strengthen the promotion and application of solar water heaters in urban markets and prioritize the promotion of high-efficiency solar water heaters; By 2015, the proportion of solar water heaters in the entire water heater industry (including electric water heaters, gas water heaters, and solar water heaters) exceeded 40%, and the market share of products with energy efficiency level 2 or above reached 50%. 
Solar thermal utilization is an important field of renewable energy utilization, and the most mature product of solar thermal utilization in China is solar water heaters. In recent years, the solar water heater industry has grown rapidly. According to statistics, in 2012, the production of solar water heaters was approximately 49.68 million square meters (about 24.84 million units), achieving sales revenue of over 40 billion yuan and providing more than 300000 job opportunities. Based on the national solar water heater inventory of 200 million square meters in 2012, it can save 30 million tons of standard coal and reduce carbon dioxide emissions by 74.7 million tons annually, with good economic, social, and environmental benefits. 
The solar water heater industry in China has formed an industrial chain that includes mechanical equipment, raw material processing, core components such as solar collector tubes and collectors, as well as the assembly, production, marketing, and installation services of complete water heaters. It has also formed a solar water heater industry cluster centered on key areas, with multiple brand enterprises emerging. By 2015, the industry will cultivate three leading enterprises with an annual production and sales volume exceeding 5 million square meters (2.5 million units), and cultivate five or more enterprises with an annual production and sales volume exceeding 2 million square meters (1 million units).