What are photovoltaic modules and how they work in photovoltaic battery
- Types of photovoltaic modules
- Photovoltaic modules are the middle of the industry chain
- Market scale of photovoltaic module industry
- Photovoltaic cells are mainly crystalline silicon cells
- Photovoltaic cells is the key to photoelectric conversion
Photovoltaic modules are based on battery integration with packaging and internal connection, which can provide DC output alone, the smallest indivisible photovoltaic cell combination device.
As the smallest effective power generation unit, photovoltaic modules undertake the function of photoelectric conversion in photovoltaic power station, and are the core part of photovoltaic power generation systems.
The core component of photovoltaic modules, photovoltaic cells, have a limited amount of power generated by a single piece, and can only be used as a power source after being connected in series and encapsulated into components.
Photovoltaic modules are composed of a certain number of photovoltaic cells connected in series and parallel by wires and packaged, mainly including cells (usually 60 or 72), interconnecting bars, bus bars, photovoltaic glass, film, backplane, aluminum frame, junction box and other core components.
Types of photovoltaic modules
Crystalline silicon modules and thin film modules
Photovoltaic modules are divided into crystalline silicon modules and thin-film modules, among which crystalline silicon modules account for 90%-95% of the total photovoltaic modules due to the high power generation of a single module, and thin-film modules only account for about 5%-10%.
Double-glass modules and single-glass modules
Crystalline silicon photovoltaic modules can be divided into double-glass modules and single-glass modules according to the back material. Most of the back-sheet materials of single-glass modules are opaque composite materials (TPT, TPE, etc.).
Currently, single-glass photovoltaic modules are still the mainstream. The annual market share of single-glass photovoltaic modules is about 70%-75%, and the double-glass modules account for about 25%-30%. Double-glass modules use glass to replace the composite backplane of single-glass photovoltaic modules, and both sides are encapsulated by glass.
Compared with single-glass photovoltaic modules, double-glass photovoltaic modules have a longer life cycle, stronger weather resistance and corrosion resistance, and lower attenuation than ordinary modules, higher power generation efficiency, both front and back power generation capabilities, and the back side can accept reflected light from the surrounding environment.
The scattered light is converted into electrical energy, and the double-sided module can increase the power generation by 10%-30% according to different ground environments.
The specific process flow of photovoltaic modules preparation can be divided into: welding, lamination, lamination, EL testing, framing, junction box assembling, clarity, IV testing, finished product inspection, packaging, etc. Among them, the links with the highest technology and value are welding and laminated. There is an article introducing welding technology in detail and you can click laser welding machine for lithium ion batteries for more understanding.
Photovoltaic modules are the middle of the industry chain
Driven by the support of industrial policies and the demand of the world market, China’s photovoltaic technology has continued to progress, and a complete industrial chain from silicon material to photovoltaic modules system construction and operation has been formed, and it has a high industrial scale advantage in the world.
The upstream of the photovoltaic industry includes smelting, ingot/pulling, and slicing of monocrystalline and polycrystalline silicon, the midstream includes photovoltaic cell production, photovoltaic power generation module packaging and other links, and the downstream includes the integration and operation of photovoltaic power station systems.
The photovoltaic industry has been in a state of rapid development in recent years, and at the same time, the manufacturing industry of photovoltaic equipment and components is also booming.
Market scale of photovoltaic module industry
At present, photovoltaic power generation has cost advantages compared with traditional fossil energy power generation.
With the advantages of cost and carbon emission reduction, photovoltaic power generation has become the main force of new power generation in the world. According to data, photovoltaic power generation ranks first in the newly installed power generation capacity in 2020, accounting for about 2020 with 39% of capacity.
In 2020, the newly installed capacity of the world photovoltaic market will be 130GW, and the total installed capacity of photovoltaic power generation will reach 756GW.
According to statistics, in 2021, China’s newly installed photovoltaic grid-connected capacity will be 53GW, a year-on-year increase of about 10%, ranking first in the world for nine consecutive years. The cumulative photovoltaic grid-connected installed capacity reached 306GW, breaking the 300GW mark, ranking first in the world for seven consecutive years.
In recent years, new technologies have continuously pushed up photoelectric conversion efficiency while reducing costs, supporting the continuous improvement of the market competitiveness of crystalline silicon cells. According to data, in terms of crystalline silicon cells, China’s cell production in 2020 will be about 135GW, a year-on-year increase of 22%.
Among them, the output of the top five companies accounted for 53% of the total cell output. Benefiting from the growth of worldwide photovoltaic demand, Chinese enterprises have continued to increase investment and technological innovation in the module sector in recent years, and the production cost of photovoltaic modules has continued to decline.
China has become the world’s largest producer of photovoltaic modules, accounting for about 70% of the world’s photovoltaic modules production. In 2020, China’s PV module production reached 125GW, a year-on-year increase of 26%. Among them, the output of the top five companies accounted for 55% of the total output of photovoltaic modules, of which the output of the top three companies exceeded 10GW.
Driven by the vigorous development of the world photovoltaic market, China’s photovoltaic industry has continued to develop in a healthy way, and all links of the photovoltaic industry chain have continued to expand, and the scale has maintained a momentum of rapid growth.
According to data, China’s polysilicon production in 2020 is about 396,000 tons, a year-on-year increase of 15.8%; silicon wafer production is 161GW, a year-on-year increase of 19.7%. The cell output was 135GW, a year-on-year increase of 22.2%. Module output was 125GW, a year-on-year increase of 26.4%.
Photovoltaic cells are mainly crystalline silicon cells
Photovoltaic cells are the underlying core components of photovoltaic power generation systems. According to the difference in materials used, they are divided into two categories: crystalline silicon cells and thin film cells. The former occupies the main market share, and the latter benefits from the development of photovoltaic buildings. The penetration rate is expected to increase.
Crystalline silicon solar cells After decades of development, the technology system has become relatively mature, the photoelectric conversion efficiency has continued to improve, and the industrial scale has expanded rapidly, and the marginal manufacturing cost has been significantly reduced.
In the current photovoltaic industry, crystalline silicon cells occupy more than 95% of the photovoltaic cell market due to the economic cost advantage and high conversion efficiency brought by economies of scale. The single crystal field is divided into two technical routes: P-type and N-type.
- P-type battery
It is prepared by doping boron into pure silicon crystals. The holes are the majority carriers and the free electrons are the minority carriers. The current mainstream P-type single crystal cell technology is PERC cell technology, which has a simple manufacturing process and low cost.
- N-type battery
It is formed by doping phosphorus element in pure silicon crystal, free electrons are multi-carriers, and holes are minority carriers. As P-type cells gradually approach their conversion efficiency limit, N-type will be the direction of next-generation battery technology.
N-type cells have the advantages of high conversion efficiency, high bifacial ratio, low temperature coefficient, and longer carrier lifetime. The main preparation technologies include PERT, TOPCon, IBC, HJT, etc.
- Thin film battery
Thin-film cells are made of a thin film into a photovoltaic cell, which uses very little silicon, making it easier to reduce costs. At the same time, it is not only a high-efficiency energy product, but also a new type of building material, which is easier to perfectly combine with buildings.
In the context of the continuous shortage of silicon raw materials in the international market, thin-film solar cells have become a new trend and new hot spot in the development of the worldwide photovoltaic market.
Photovoltaic cells is the key to photoelectric conversion
Photovoltaic cells are the key components of photoelectric conversion in photovoltaic modules, which are used to directly convert the light energy of the sun into electrical energy. After being connected in series, they are packaged and protected to form solar cell modules, and then configured with components such as controllers and mounting system brackets to form photovoltaic power generation devices.
The production process of photovoltaic cells from silicon wafers to working cells mainly requires seven processes to complete the preparation: texturing and cleaning → diffusion junction → etching → secondary cleaning → preparation of anti-reflection film → printing electrodes → sintering. And there is an odm best lithium battery manufacturer who has experience in solar battery and provide professional solutions to users around the world. It is TYCORUN Energy.
Photovoltaic power generation is a technology that directly converts light energy into electrical energy by using the photovoltaic effect of the semiconductor interface.
When light strikes a photovoltaic cell and the light is absorbed at the interface layer, photons with sufficient energy can excite electrons from covalent bonds in both P-type and N-type silicon, resulting in electron-hole pairs.
Under the action of the built-in electric field of the P-N junction, holes flow from the N region to the P region, and electrons flow from the P region to the N region, and a current is formed after the circuit is turned on.