company news

The research on solar thermal energy utilization technology has been paid attention to since the 1970s, especially in the United States, Japan, and Australia. There have been quite mature research and development results in many application fields. Even so, there are still some issues to be solved. Since the 1990s, European countries have begun to devote themselves to the research and development and promotion of solar thermal energy and other renewable energy sources. According to the report of ESTIF (European Solar Thermal Industry Federation) (ESTIF, 2003), after more than 30 years of development, various Different types of collectors, domestic solar water heating systems suitable for various climate types and conditions of use have been developed quite well, but in some fields, such as solar heating, solar cooling and industrial process heat utilization, etc., are still not powerful enough of commercial products. The resistance encountered in research and development in the field of solar energy mainly lies in:

• Most of the solar energy companies are small and medium enterprises, which cannot have sufficient financial resources to support medium and long-term R&D activities.
• National funding for R&D is often low, and in some countries even non-existent.
• National R&D programs in energy efficiency and renewable energy are often not well received by SMEs.

Some of the main research and development topics currently in Europe are as follows:
1. Medium and long-term heat storage technology
In summer, when solar energy is at its maximum, hot water demand is usually low, and affordable hot water storage tanks can collect heat from periods of strong solar radiation (sunny or summer) and store it in periods of weak solar radiation (cloudy or winter) to use. Typically a building receives 10 times more solar energy than its thermal needs throughout the year, and a well-designed seasonal thermal storage tank can even completely replace the use of traditional fossil fuels. There are already some experimental seasonal thermal storage tanks in Europe with good initial results, but there are still many improvements to be made before becoming an affordable commercial product. The main research and development directions are:

• Intensive heat storage system
• thermal storage
• chemical formula storage

2. Solar cooling
In the near future, the development of solar-assisted cooling systems is very worth looking forward to. Usually, when the solar radiation is the strongest, people have the greatest demand for air-conditioning. Although solar-assisted cooling systems have appeared on the market, there are still many technical difficulties to be overcome in order to expand its application market. The main research and development directions are:

• Low temperature (50~80 ℃) solar thermal cooling system
• Small ( 3~10kW ) thermal energy refrigeration system
• Solar cooling system integrated with domestic hot water and heating

system integration
Solar water heating systems must be integrated with existing heating systems or building structures. In order to further develop the market, the solar water heating system must be applicable to various conditions and possible application methods. The main research and development directions are:

• Solar heating and combined solar heating/hot water systems (system development and simplification, control logic, standardization)
• Combined use with other renewable energy sources (biomass energy, heat pumps)
• Integration with district heating systems
• Inexpensive industrial process heat utilization
• Small thermal storage tanks (thermal stratification, normalization)
• Integrated collectors integrated into the roof
• Façade wall building material heat collector

system monitoring
In order to allow users and potential investors to have an evaluation basis for the actual energy and cost savings of the solar water heating system, it is necessary to measure the actual solar energy gain for the installed system. Therefore, more Reliable and less expensive measuring equipment is a development focus.
desalination
Solar collectors can be effectively used in desalination of sea water and disinfection of drinking water. The market potential in this aspect is quite large, because many areas lacking drinking water have high solar energy, and these areas are usually in the traditional Obtaining energy is also not easy. Although there are examples of applications, further research and development is still needed to reduce costs and expand the market.