What’s the Construction of a Small Custom Solar Panel?

A solar panel is a device that converts solar energy into electrical energy. Since solar panels can be customized flexibly, small custom solar panels have been applied to many off-grid solar applications, such as solar chargers, solar attic fans, and solar LED lights etc.

Usually the solar panels we see are a complete piece of panel, but do you know what the internal structure of the solar panels is?

Small Custom Solar Panel

Here, we mainly introduce the crystal silicon solar panels that are more common on the market as an example.

The structure of crystalline silicon solar panels is usually: tempered glass / EVA / solar cell / EVA / backsheet.

Solar Panel Construction

(1) Tempered glass: Its function is to protect the main body of power generation (such as solar cells). The choice of light transmission is required:

1. The light transmittance must be high (generally 91% or more); 2. Ultra-white tempering treatment.

(2) EVA: Used to bond fixed tempered glass and solar cell. The quality of transparent EVA material directly affects the life of solar panels. EVA exposed to air is prone to aging and yellowing, thus affecting the light transmission of solar panels, so then, affecting the power generation quality of the solar panels. In addition to the quality of the EVA itself, the influence of the lamination process of the custom solar panel manufacturers is also very large. For example, if the EVA adhesiveness is not up to standard, the bonding strength of EVA and tempered glass and backing plate is insufficient, which will cause EVA early aging, thus affects solar panel’s life.

(3) Solar Cell: Solar cells are the core components of solar panels. The main function of solar cell is power generation. 

(4) Back sheet: Its function is sealed, insulated and waterproof. Generally, materials such as TPT and TPE must be resistant to aging. Most solar panel manufacturers are guaranteed for 25 years. Tempered glass and aluminum alloys are generally no problem. The key is whether the back sheet and silica gel can meet the requirements.

 When the solar cell is soldered, the next step is to laminate, according to the following sequence, tempered glass / EVA / solar cell / EVA / back plate, stacked, and then sent to the laminator for vacuuming, and high temperature lamination. EVA is solid at room temperature, but when EVA is exposed to high temperatures, it becomes liquid. Therefore, in the laminator, after the EVA is melted into a liquid state, the solar cell sheet and the tempered glass and the back sheet are glued together.

Just after laminating from the laminator, usually on the four sides of the solar panel, there is some excess EVA overflow, which requires a knife to cut and burr. After processing, a complete solar panel is produced.

Editor: Carrie Wong / WSL Solar

Furniture Giant IKEA Will Directly Retail Solar Panels

Recently, Swedish multinational home furnish IKEA was interviewed by interviewers about the PV business model of flat furniture retailers, and said that it will be the first trial operation of “Solstrale” Solar panels in the Swedish market this summer, by 2025. Plans to provide solar panels in his worldwide stores.

According to IKEA, this idea is borrowed from the experience of selling solar panels in Germany. “With the rapid development of the solar industry in recent years, especially the more simplified regulations and better returns, it is a very good choice to invest in solar panels in Sweden today.” Jonas Carlehed, Swedish Sustainable Development Manager, IKEA Group Say.

In the past two years, the Swedish government has also made many efforts in the solar industry, such as improving the regulation of solar energy and increasing the budget for rooftop PV.

IKEA said the company is negotiating with potential suppliers and partners on the quotation and sales suppliers of Swedish Solstrale photovoltaic panels. The right partners will help IKEA avoid problems similar to those encountered in Germany.

According to IKEA, the company plans to expand Solstrale’s sales to all markets worldwide by 2025. “We want to help our customers produce their own renewable energy at home, which is good for the climate, the environment, and the wallet.”

In fact, IKEA furniture’s innovative move in the field of solar energy has led the wave of rooftop PV retail. As early as the first two years, IKEA has proposed a plan to sell solar roof systems in its official website and physical stores, and to land in several countries such as Europe. At present, due to certain factors such as ideological concepts and living environment, this practice has not yet been carried out in other countries outside Europe.

This time, IKEA will split the solar panels in the rooftop photovoltaic system, which will attract more customers to turn their attention to solar furniture. On the other hand, it will leave customers with more DIY space on their roof. But selling only the battery board also means that the electrical requirements of the customer are more demanding, assembly and installation is a problem, and testing and maintenance will become another big problem in the later period. Has IKEA conducted market research before this? How is the customer’s acceptance? Do not ask whether it is profitable (a company with a strong sense of clean energy, often very capricious), can this model work normally?

Building a platform for retail components is not a pioneering move in China. In 2017, Yingli opened the first “photovoltaic supermarket”, specializing in the necessary components of photovoltaic modules, inverters, brackets and other photovoltaic systems, and the four areas of knowledge, product display, business negotiation and customer experience in the supermarket. Also made a preliminary preparation for retail. However, most of the supermarket’s customers are local dealers. They often intuitively feel the difference between the components and carry out the “shopping around” and choose the preferred purchase. Yingli “photovoltaic supermarket” industry has heard about it, but it is basically insulated from the outside world. Compared with the platform for the public, it is relatively occluded.

IKEA is different. It is an internationally renowned Fortune 500 company, referring to an industry giant that modern comfort furniture can’t get around. In any case, IKEA does photovoltaic, which is not only the trend of future development, but also the leader of the new home era. IKEA has set up a template for home decoration around the world. After three or five years of market education, people will install photovoltaic panels on the roof. Not only is it no longer strange, but it will also set off a wave of competing installation.

Statistics on the import & export of photovoltaic wafers, solar cells & solar panels in China in the first quarter of 2019

In the first quarter of 2019, solar cells, solar panels, and photovoltaic wafer export data were released. What is the export market like? Let’s take a look!

Solar cell

In the first quarter of 2019, China’s solar cell exports totaled US$400 million, an increase of 35.71% year-on-year; installed capacity was 2,777 MW, a year-on-year increase of 100.5%. Mainly exported to South Korea, India, Vietnam, Turkey and Germany. Among them, Aixu, Jingao, Tongwei, Suntech, Tianhe, and Shunfeng Optoelectronics have accounted for about 50% of the global market.

Solar panels

In the first quarter of 2019, China’s solar panel exports totaled US$4.39 billion, up 31.89% year-on-year; installed capacity was 16.78GWMW, up 77.63% year-on-year. Mainly in Vietnam, the Netherlands, India, Japan, Australia as the main market.

Photovoltaic silicon wafer

In the first quarter of 2019, the export value of photovoltaic wafers in China decreased significantly. The total export value of the world was 582 million US dollars, down 37.06% year-on-year; the installed capacity was 1.346 billion pieces, down 11.19% year-on-year. Most are sold to Korea, Malaysia, Taiwan, Vietnam, Thailand and India.

What is the test method for solar panels

Solar Panel Test

AM1.5 refers to the spectrum. Since solar panels are generally different in efficiency under different light intensity or spectral conditions, AM0 spectrum (1.367 KW/m2) is generally used for space solar panels, and AM1.5 spectrum is generally used for ground applications.
(ie, the ground at noon, clear sunlight, 1.000 KW/m2) as a standard source for testing the efficiency of solar panels. The solar panel’s spectral efficiency in AM0 is generally 2 to 4 percentage points lower than the AM1.5 spectral efficiency. For example, a Si solar cell with an AMO efficiency of 16% has an AM1.5 efficiency of about 19%.

Solar Panel Power Test
Test conditions: AM1.5, 1000W/m2, 25°C Output power Tolerance: ±5%
Standard test conditions: AM1.5, 1000W/m2, 25°C interpretation

AM1.5, 1000W/m2, 25°C is the test standard for IEC61646–Design and finalization of thin film photovoltaic modules for the ground (GB/T18911-2002). It is also the general test standard for GB/T11011-1989–Amorphous silicon solar cell electrical performance test.

AM means air-mass, defined as: path-length through the atmosphere relative to vertical thickness of the atmosphere, which is the vertical distance of the actual distance of light passing through the atmosphere from the upper atmosphere. AM1.5 is the actual distance of light passing through the atmosphere to 1.5 times the vertical thickness of the atmosphere.

1000W/m2 is the irradiance of the light of the standard test solar cell.

25 ° C is working at a temperature of 25 ° C. The efficiency of the solar cell will decrease with the increase of temperature. When it is used, the temperature will rise, and then the temperature coefficient will give the voltage and current and output power of his work.

Test Methods
If you don’t have a special instrument, you can buy one or several 500W metal halide lamps. Other heat sources are also available. When the area of ​​the solar panel is large, it can be arranged according to the illumination range of the lamp, and then equipped with a voltage regulator, the distance is about 15-20CM, and the data is measured by the light meter: 40,000 LUX, which is the currently recognized international standard test methods. Then put the solar panels to test.