New Breakthrough in Solar Energy Utilization in Yunnan

The power consumption of household appliances in ordinary households is around 2000 watts. If you install “nearly 20 square meters of glass that will generate electricity” on several windows, then these household appliances can “eat on the sky”. Sunlight that shoots into the windows “turns on” televisions, refrigerators, and computers. Yunnan, which started earlier as a solar energy utilization technology, has the potential to realize the “modern energy-saving life” mentioned above.

Yunnan has also made new breakthroughs in solar energy utilization technology. Recently, the "liquid adhesive transparent photovoltaic modules" supported and developed by the Ministry of Science and Technology, the Yunnan Science and Technology Department and the Kunming Productivity Promotion Center have passed important weatherability tests, and many indicators have reached or even surpassed the international level. After passing domestic and international certification, it is expected to achieve mass production.

Start: R&D keeps pace with the world

In the fifth floor of No. 1 standard factory building in Kunming Export Processing Zone, a clean production workshop for solar cells and their components is under preparation. This is a new factory building after Kunming Science and Technology Innovation Park graduated from the technology-based SME Yunnan Zhuoye Energy Co., Ltd., which has been incubating for 5 years.

In the conference room next to the workshop, two pieces of glass embedded with black squares lean against the wall. Because of the unique appearance on the "outside appearance" of a row of pure black solar panels next to them, these two modern "glasses" are particularly prominent. In fact, they are the "new generation" of this solar panel family, and there is a scientific name liquid glue transparent photovoltaic module around.

In 2004, when the solar PV industry in Yunnan began to decline, technology research and development in this area did not slow down. In that year, the Solar Energy Research Institute of Yunnan Normal University, Yunnan Zhuoye Energy Co., Ltd., and Kunming Photovoltaic Technology Co., Ltd. gathered a group of experts in solar energy technology research, followed the pace of the world and began research on transparent photovoltaic modules. "On the technical level, we have not started later than the European photovoltaic powerhouse." said Liu Zuming, a professor at Yunnan Normal University and deputy director of the National Solar Photovoltaic Energy System Standardization Committee, executive director of the China Renewable Energy Society and Zhuoye Energy Manager.

Achievements: New Types of Building Materials for "Sucking" Photovoltaic Power Generation

In the five years of research and development, the biggest difficulty lies in how to fix the solar panels in the glass without reducing the transmittance and not easily falling off. "We tried to use a conventional film package, but the effect is not good." Liu Zuming said. As a result, this team of experts began to try to develop a new "adhesive" liquid sealant.

After hundreds of experiments and technical improvements of three generations of products, many properties of liquid packaging adhesives have been continuously improved. For example, early gels experienced severe yellowing in high-temperature tests (which would affect the light transmission effect). After many improvements, the adhesives did not have appreciable yellowing at 85°C and -40°C. The early adhesives had poor water resistance, and the improved adhesives will not fall off even after 3 months of continuous immersion, which meets the requirements of international PV module standards.

It is worth mentioning that the liquid encapsulating glue has a higher transmittance in the short wavelength range than the imported glue. Experts encapsulate monocrystalline silicon solar cells on glass using UV radiation curing technology. The crystalline silicon transparent building PV modules manufactured are all higher than national standards in terms of pressure resistance and insulation, and can be used as conventional roofs or Use for curtain wall glass. "In this way, liquid plastic transparent photovoltaic modules can be used as a new type of building material, which is widely used in construction." Liu Zuming said.

Application: Expected to achieve mass production

According to Liu Zuming, solar energy, as a low-density energy source, requires a large installation area to generate electricity on a scale. Although there is no land restriction for the application in the desert, long-distance transmission of electricity not only brings higher costs, but also leads to greater line losses. The application closest to the user is photovoltaic building materials combined with architecture. This year, transparent photovoltaic modules have been applied to high-rise buildings in China, indicating that this form of solar energy utilization has begun to be accepted domestically. From a technical perspective, the use of liquid crystal encapsulated transparent photovoltaic modules as a key research project of the Ministry of Science and Technology has filled China's gap in this field.

Thanks to technological superiority, the cost of liquid adhesive transparent PV modules is lower than that of European countries under the same performance. Therefore, this module is expected to achieve mass production after passing national and international certifications.

From the perspective of the external environment, this year, affected by the debt crisis, the major European markets reduced the subsidies for photovoltaic power generation, causing 90% of the market outside the Chinese PV industry to shrink in volume. It is reported that in the first three quarters of this year, China's 10 photovoltaic companies listed in the United States had 8 net profits and losses, and there were already about 50 PV companies in the country closed down. In this regard, Liu Zuming is not worried about the market for new products. He believes that, on the one hand, domestic photovoltaic products have grown too fast in the past few years. This shock is a major reshuffle for domestic photovoltaic companies, which helps product prices fall back to normal levels and further optimize the industrial structure. On the other hand, in the Economic Development Zone of Kunming, since the establishment of the National Innovation Base for Photo-electronic Materials and Products Science and Technology, the support for the optoelectronics industry has been continuously increased. With the increasingly perfect industrial support, the company will achieve rapid development. .