Comprehensive introduction and overview of solar cells

I. Comprehensive analysis of solar cells
Solar cells, as a device that converts solar energy into electrical energy, have attracted much attention in recent years. Its working principle is based on the photoelectric effect. By absorbing photons in sunlight, electrons and holes are stimulated, and then current is generated. Solar cells have the advantages of being environmentally friendly, renewable, and pollution-free, and are widely used in many fields such as homes, industries, and transportation. Next, we will give a comprehensive introduction and overview of solar cells.

 

II. 1. Overview of solar cells
Solar energy, which occupies a core position in renewable energy, derives its energy from the sunlight we are familiar with. Biomass energy, wind energy, ocean energy, and hydropower, these seemingly diverse energy forms, in fact, all trace back to the source of solar energy. Broadly speaking, solar energy covers all the renewable energy mentioned above. When we specifically refer to solar energy as a renewable energy source, we usually refer to the direct conversion and utilization of solar energy.

Solar thermal utilization technology, that is, the efficient conversion of solar radiation energy into thermal energy through a conversion device, and then the use of this thermal energy to generate electricity. Similarly, solar photovoltaic power generation technology, that is, the process of converting solar radiation energy into electrical energy, is also an important technology. In this field, photoelectric conversion devices, such as the photovoltaic effect principle of semiconductor devices, play a core role.

In the 1950s, the field of solar energy utilization ushered in an important technological leap. In 1954, Bell Laboratories in the United States successfully developed a 6% practical single-crystal silicon cell, laying the foundation for the practical application of solar cells. In 1955, Tabor of Israel proposed an important theory of selective absorption surface, and based on this theory, developed an efficient selective solar absorption coating, which further promoted the development of solar energy utilization technology.

In addition, solar cells also show their unique characteristics. It is similar to a huge PN junction, which can efficiently convert solar energy into electrical energy. Under standard lighting conditions, solar cells can generate a rated output voltage of 0.48V. At the same time, it also has all the characteristics of the PN junction, which enables it to continuously generate electricity under sunlight.

In practical applications, solar cell modules are usually connected by multiple solar cells and used in solar lighting fixtures and other equipment. These components have a negative temperature coefficient, that is, the voltage will drop by 2mV for every degree increase in temperature. At the same time, they also have key parameters such as Isc (short circuit current), Im (peak current), Voc (open circuit voltage), Vm (peak voltage) and Pm (peak power), which are essential for the normal operation and optimization of the system.

It is worth mentioning that the open circuit or short circuit state of the solar cell will not damage it. In fact, we use this feature to control the charging and discharging of the system battery. This intelligent control method further ensures the stability and durability of the solar cell.
The output power Wp of the solar cell is measured under standard sunlight conditions. This condition follows the European Commission's 101 standard, including a radiation intensity of 1000W/m2, an air mass of AM1.5 and a battery temperature of 25℃. In practical applications, such conditions are approximately equivalent to the sunlight around noon on a sunny day. However, many people mistakenly believe that as long as there is sunlight, the solar cell can generate the rated output power, and even think that it can be used normally under fluorescent lights at night. In fact, the output power of the solar cell changes dynamically and is affected by many factors such as time and place. Therefore, the output power of the same solar cell will be different at different times and places.

 

III. 2. Photovoltaic effect
The photovoltaic effect, or photovoltaic effect for short, refers to the phenomenon of potential difference between different parts of an inhomogeneous semiconductor or a combination of a semiconductor and a metal under illumination. Solar cells use this effect to convert solar radiation into electrical energy through the principle of photoelectric conversion. This photoelectric conversion process is called the "photovoltaic effect", so solar cells are also called "photovoltaic cells".

The semiconductor material used for solar cells is a special substance whose properties are between conductors and insulators. Similar to the atoms of ordinary substances, the atoms of semiconductors are composed of positively charged nuclei and negatively charged electrons. Taking semiconductor silicon as an example, its outer layer of atoms has 4 electrons, which move around the nucleus in fixed orbits. When excited by external energy, these electrons will break away from the orbit and become free electrons, leaving a "hole" in the original position.

In pure silicon crystals, the number of free electrons and holes is equal. However, by doping with specific elements, such as boron and gallium, the conductive properties of silicon can be changed. These elements can capture electrons, turning silicon into a hole-type semiconductor, represented by the symbol P; while the addition of elements such as phosphorus and arsenic will turn silicon into an electron-type semiconductor, represented by the symbol N. When these two semiconductors combine, their interface will form a P-N junction. It is this P-N junction that constitutes the core of the solar cell. It is like a barrier that hinders the free movement of electrons and holes.

When the solar cell is exposed to sunlight, electrons absorb light energy and move to the N-type region, causing the N-type region to be negatively charged; at the same time, holes move to the P-type region, making the P-type region positively charged. In this way, an electromotive force, commonly known as voltage, is generated at both ends of the P-N junction. If metal wires are welded to the P-type layer and the N-type layer respectively and the load is connected, current will flow in the external circuit. By connecting multiple such battery elements in series and in parallel, the required voltage and current output can be generated.

At present, the most mature and commercially valuable solar cell is the silicon solar cell.
Solar cells, a device that efficiently converts solar energy into electrical energy through the photovoltaic effect, have a basic structure as shown in the figure above. When two different types of semiconductor materials, N-type and P-type, come into contact with each other, a built-in electric field pointing from P-type to N-type is formed at their interface due to diffusion and drift effects. When sunlight shines on the surface of the solar cell, photons with energy exceeding the bandgap will excite electron and hole pairs. These unbalanced minority carriers are effectively separated under the action of the internal electric field and accumulated at the positive and negative electrodes of the battery, thereby providing a stable current output for the external load.

 

IV. 3. Development trend of crystalline silicon solar cells
Crystalline silicon solar cells are developing in the direction of high efficiency and thin film. In terms of high-efficiency monocrystalline silicon cells, the back point contact cell (PCC) of Stanford University, the passivated emitter region cell (PESC, PERC, PERL) of the University of New South Wales (UNSW), and the localized back surface field (LBSF) cell of the Fraumhofer Institute for Solar Energy in Germany are all outstanding. At the same time, polycrystalline silicon high-efficiency cells have also attracted much attention. Their advantage is that they can directly prepare large-size square silicon ingots suitable for large-scale production, with simple equipment and energy-saving manufacturing process. Although the efficiency of polycrystalline silicon cells is affected by the material and grain boundaries, its performance has been significantly improved by adopting technologies such as gettering, passivation, and back field. Among them, the conventional aluminum gettering process is formed by sintering after evaporating an aluminum film on the back of the cell, which not only simplifies the manufacturing process but also helps to improve the efficiency of the cell. In addition, hydrogen passivation, as an effective method to improve the quality of polycrystalline silicon, can significantly reduce defects such as dangling bonds in the silicon body through ion implantation or plasma treatment. At the same time, a layer of silicon nitride anti-reflection film is coated on the surface of polycrystalline silicon solar cells by PECVD, which can also achieve hydrogen passivation of polycrystalline silicon. In addition, surface oxygen passivation technology has also been widely used in high-efficiency solar cells, especially in photovoltaic-grade crystalline silicon materials, where the effect is more obvious. Thermal oxidation is one of the commonly used technical means, and PECVD surface oxidation at a lower temperature also shows certain potential.
Surface treatment of polycrystalline silicon solar cells

Due to the presence of multiple crystal orientations on the surface of polycrystalline silicon solar cells, it is difficult to obtain an ideal velvet structure by etching like single-crystal silicon with (100) crystal orientation. Therefore, researchers are committed to exploring various surface treatment methods to achieve the purpose of anti-reflection. Among them, the use of multi-blade grinding wheels to groove the surface of silicon wafers can shorten the process time of 10cm×10cm silicon wafers to 30 seconds, showing certain practical potential.

In addition, porous silicon is also regarded as a practical option for anti-reflection films for polycrystalline silicon solar cells. Its anti-reflection effect is comparable to that of double anti-reflection films, thereby increasing the efficiency of polycrystalline silicon cells to 13.4%.

Research and development of thin-film batteries

In order to further reduce the cost of solar cells, the photovoltaic field continues to explore the research and development of thin-film batteries. At present, amorphous silicon thin-film batteries, gallium sulfide (CdTe) batteries, and copper indium selenide (CIS) batteries have been successfully developed. In particular, amorphous silicon batteries have a relatively simple preparation process and low cost, and have received widespread attention.

 

Packaging of solar cells

The packaging form of solar cells is crucial to the working life of the battery. At present, the lamination process has become the mainstream, which can ensure the working life of solar cells for more than 25 years. In contrast, although the initial appearance of the drip encapsulation is beautiful, the working life of the solar cell is limited to 1~2 years. Therefore, for applications such as low-power solar lawn lights that do not require a high life span, the drip encapsulation form can be used; while for solar lights with a clear service life, it is recommended to choose the laminated encapsulation form. In addition, a new type of silicone gel material is also used for drip encapsulation of solar cells, and its working life is said to be up to 10 years.

 

Classification of photovoltaic power generation systems

Photovoltaic power generation systems can be divided into two types: independent and grid-connected. Independent photovoltaic power generation systems are mainly used in remote areas or areas without grid coverage; while grid-connected photovoltaic power generation systems are connected to the grid, and the generated electricity can be directly input into the grid.

1. Independent solar AC power generation systems usually include the following core components:

Solar cell array: It consists of solar cell modules arranged and connected in a specific way, which are supported by brackets and foundations.

Energy storage battery: It can be selected according to actual needs and may be different types of rechargeable batteries.

Controller: It is specifically responsible for controlling the charging process of the solar cell array to the energy storage battery. It has multiple protection functions to ensure the safe and stable operation of the system.
Inverter: A device that converts the DC power provided by the energy storage battery into the required AC power. For example, in China, the output voltage is 220V and the frequency is 50Hz.
Distribution box and connecting wires: Responsible for connecting the various components of the system and managing the output power.

 

2. Independent solar DC power generation system
Usually includes the following core components:

Solar cell array: It is composed of solar cell modules arranged and connected in a specific way, which are firmly supported by brackets and foundations.

Energy storage battery: It is selected according to actual use needs and may include different types of rechargeable batteries.

Controller: It is specifically responsible for monitoring and controlling the charging process of the solar cell array to the energy storage battery. Its built-in multiple protection functions are designed to ensure the continuous safe and stable operation of the system.

Distribution box and connecting wires: Responsible for connecting the various components in the system to each other and effectively managing the output power.

 

3. Grid-connected solar AC power generation system
Grid-connected solar AC power generation system usually includes the following components:

Solar cell array: It is composed of solar cell modules arranged and connected in a specific way, which are firmly supported by brackets and foundations.

Energy storage battery: Select according to actual use needs, which may include different types of rechargeable batteries.

Controller: Responsible for monitoring and controlling the charging process of the solar array to the energy storage battery. Its built-in multiple protection functions ensure the continuous safe and stable operation of the system.

Grid-connected inverter: Converts the DC power of the energy storage battery into the required AC power, such as the 220V50Hz commonly used in China.

Distribution box and connecting wires: Responsible for connecting and managing the output power of various components in the system.

In addition, solar lighting systems are also an important application area. The design of solar lamps needs to consider the specific conditions of the use area. In East China, the appropriate ratio between the rated output power of solar cell modules and the input power of lamps is about 2~4:1, and the specific ratio depends on the working time of the lamps and the lighting needs of continuous rainy days. The installation of solar cells is also a key link. Its tilt angle and direction will affect the output power and service life. In the lower reaches of the Yangtze River, the ideal tilt angle of solar cells is about 40 degrees, facing due south. At the same time, in order to prevent the so-called "heat island effect", that is, a single solar cell may be damaged by heat after being blocked, a solar cell module composed of multiple solar cells is actually used, and measures such as tilting and installing bird-proof pins are taken.

Regardless of the style and power of solar lamps, the charge and discharge control circuit, one of its core components, is crucial. In order to ensure the durability of the battery, its charge and discharge conditions must be strictly controlled to prevent overcharging and deep discharge. In addition, due to the large fluctuation of the input energy of the solar photovoltaic power generation system, the charging control of the battery in the photovoltaic power generation system is more complicated than that of ordinary batteries. The performance of solar lamps often depends on the design and implementation of the charge and discharge control circuit. If there is a lack of high-performance charge and discharge control circuit, the performance of solar lamps will be difficult to guarantee.

 

In the context of the widespread application of solar photovoltaic power generation, the selection of lead-acid batteries for energy storage is particularly important. From large-scale solar photovoltaic projects in Europe and the United States to my country's Guangming Project, solar photovoltaic power generation has shown a strong development momentum. With the advancement of photovoltaic technology and the popularization of low-cost photovoltaic modules, application scenarios such as solar lamps, photovoltaic power stations, and household photovoltaic power sources have put forward higher requirements for batteries. At present, valve-regulated sealed lead-acid batteries, colloidal lead-acid batteries and maintenance-free lead-acid batteries have become the mainstream energy storage power sources in photovoltaic systems. The weather resistance of these batteries is crucial to ensure the stable operation of the system. This article will focus on the impact of temperature on battery life and capacity in natural environments and the corresponding solutions, and at the same time deeply analyze the key points of selecting energy storage lead-acid batteries.

 

5. The impact of temperature on the life of lead-acid batteries
VRLA lead-acid batteries are very sensitive to temperature changes. According to the Arinius principle, when the temperature exceeds 40°C, its life will be halved for every 10°C increase. The main reasons for the end of battery life include drying up of sulfuric acid electrolyte, thermal runaway and internal short circuit.

Drying up of sulfuric acid electrolyte is one of the key factors affecting the life of lead-acid batteries. Drying up of acid will cause the battery capacity to decrease or even fail completely, which is a problem unique to lead-acid batteries. Possible reasons include low gas recombination efficiency, hydrogen and oxygen evolution and water evaporation, water seepage inside the battery shell, improper control valve design, and mismatch between charging equipment and battery voltage. It is worth noting that as the ambient temperature rises, the water loss rate caused by the three factors (2), (3) and (4) will accelerate, thereby accelerating the dry-out failure of the lead-acid battery.

In addition, thermal runaway is also a major challenge faced by lead-acid batteries. During the charging and discharging process, the battery generates heat. If it is not discharged in time, the battery temperature will continue to rise. Especially when working in a high temperature environment, the heat accumulated inside the battery is more difficult to dissipate, which may lead to overheating, increased water loss, increased internal resistance and a vicious cycle, gradually developing into thermal runaway and ultimately causing battery failure.

 

VRLA lead-acid batteries have extremely poor thermal conductivity and extremely small heat capacity due to their unique lean liquid tight assembly design and 10% pores in the separator. This makes VRLA lead-acid batteries more prone to thermal runaway in high temperature environments. Since the amount of gas discharged by the safety valve is limited, it is difficult to take away the heat inside the battery. Once thermal runaway occurs, the battery will be severely deformed, ruptured and completely fail.

On the other hand, internal short circuit is also a cause of lead-acid battery failure. This is mainly caused by the degradation and aging of the diaphragm material, the shedding and expansion of the active material, or the penetration of the diaphragm by the dendrites generated during the charging process. After deep discharge, the adsorption separator of the battery is prone to lead velvet or dispersed precipitation, or the formation of dendrites, resulting in micro-short circuits of the positive and negative plates.
Due to the negative electrode redundant design of VRLA lead-acid batteries, the charging efficiency of the negative electrode is higher than that of the positive plate in the early and middle stages of charging, so the negative electrode will first generate enough velvet lead, which is conducive to the recombination reaction of oxygen. In the production process of batteries, the degradation of battery performance can be slowed down by controlling the amount of negative electrode active material.
In addition, additives such as metal salts or oxides such as zinc, cadmium, lithium, cobalt, copper, and magnesium are commonly used in lead-acid batteries to improve battery performance. These additives act as strong electrolytes, and their ions migrate to the negative electrode during discharge. These metal ions have a chemical coordination effect, which can reduce the probability of lead sulfate formation. Even if lead sulfate is formed, its structure is relatively soft and easier to soften or reduce.

When using the battery, try to maintain a stable temperature and avoid drastic temperature changes to reduce the possibility of dendrite precipitation. In summary, high temperature will accelerate the battery's water loss and drying, thermal runaway, positive grid corrosion and deformation, while low temperature may cause negative electrode passivation failure. Temperature fluctuations will accelerate the internal short circuit of lead-acid batteries, and these factors will have an adverse effect on battery life.

 

VI. Effect of temperature on lead-acid battery capacity

(I) The first type of early capacity loss, referred to as PCL-Ⅰ

The main culprit for the sudden drop in lead-acid battery capacity is the barrier layer. This barrier is derived from the regeneration defects and semiconductor effect of the Pb-Ca-Sn-Al alloy. It builds a unidirectional conductive barrier between the positive electrode active material and the grid. This barrier layer is composed of complex crystals with semiconductor properties and is sensitive to temperature. By improving the semiconductor doping process such as battery alloys and lead paste additives, we have successfully improved the conductivity by taking advantage of the sensitivity of semiconductor crystals to purity, thereby effectively alleviating this failure mode.

 

(II) The second type of early capacity loss, referred to as PCL-Ⅱ

The real culprit for the slow drop in lead-acid battery capacity is not the common grid corrosion, sulfation or active material shedding, but the expansion of porous active materials. This expansion is particularly evident in the softening process of PbO2→PbSO4, which not only causes the positive active material to become soft and the complex structure to be damaged, but also gradually causes the active material to soften and fall off, which in turn causes the positive plate to lose capacity at a slower rate.

 

(III) The third type of early capacity loss, referred to as PCL-Ⅲ

The problem of lead-acid batteries being unable to charge often stems from the reduction or loss of the activity of the negative electrode additives. This can lead to difficulty in charging, poor acceptance and insufficient recharging, and ultimately lead to sulfation of the bottom 1/3 of the negative plate.

Under high temperature conditions, the negative electrode additives will decompose or dissolve in the electrolyte, leading to early losses and then passivation of the negative electrode velvet lead. On the contrary, under low temperature conditions, due to the reduced solubility, even if the discharge current is the same as the concentration at low temperature and the discharge rate remains unchanged, the saturation will increase relative to the low equilibrium solubility. In addition, low temperature will increase the viscosity of the acid solution and reduce the acid diffusion rate, thereby increasing the internal resistance of the battery and affecting its high-speed mass transfer performance.

 

The thickness of the passivation layer is closely related to the crystal size, porosity and pore structure of lead sulfate, which are closely related to the solubility of lead sulfate and the saturation of the solution on the surface of the lead electrode. Under low temperature, high current density and sulfuric acid concentration, the saturation of the solution on the surface of the negative electrode will be too high, resulting in the thickening of the passivation layer, which can easily cause the battery to fail due to discharge difficulties. At this time, the negative plate can neither be charged nor discharged.

The mechanism and degree of the influence of temperature on the above factors involve theories from multiple disciplines, including electrochemical thermodynamics, electrochemical kinetics, etc. It is worth noting that high temperature does cause the oxidation failure of additives in the battery, which in turn causes the active material to fall off and accelerates the early capacity decay of the battery. This decay will eventually shorten the life of the lead-acid battery and reduce its reliability.

 

In addition, the corrosion of the positive plate is also a problem that cannot be ignored. According to the principle of chemical thermodynamics, the higher the ambient temperature, the greater the discharge depth of the lead-acid battery, and the higher the electrolyte density, which in turn aggravates the corrosion of the grid. Long-term storage will thicken the corrosion layer, accompanied by deformation and stretching of the grid, resulting in a decrease in the tensile strength of the grid. When the active material falls off or the corrosion product is too thick, the grid resistance will increase, thus affecting the battery capacity. Once the battery capacity drops by 20%, it can be judged as failed.

In summary, as an electrochemical container, the battery is very sensitive to changes in ambient temperature. The ambient temperature not only affects the life of the battery, but also has a direct impact on its capacity. The two are interrelated and inseparable.

Development of colloidal lead-acid batteries (valve-regulated lead-acid batteries)
In recent years, lead-acid batteries have been widely used in the field of solar lamps. However, when VRLA lead-acid batteries work around the clock in natural environments, their weather resistance faces challenges, especially in the temperature range of -20℃~40℃. In order to solve this problem, we have successfully developed a colloidal battery with better weather resistance, whose operating temperature range can reach -40℃~60℃, further expanding the application range of lead-acid batteries.

 

The colloidal lead-acid battery adopts a unique rich liquid design scheme, and its acid liquid is increased by 20% compared with the VRLA lead-acid battery. The battery is filled with gel electrolyte around the pole group and between the tanks, which makes it have a large heat capacity and excellent heat dissipation. In addition, the colloidal battery also overcomes the above three problems of early capacity loss and has the following significant advantages:

 

First, it uses a special non-liquid non-gel electrolyte to inhibit the softening and shedding of the active material of the positive plate by increasing the assembly pressure (especially the pressure on the surface of the positive plate). At the same time, the well-designed control valve increases oxygen recombination and reduces water loss, thereby extending the battery life.

Second, the grid structure of the colloidal battery is carefully designed, using special process means and material formulations. This structure forms micropores, increases the reaction interface between the electrode and the electrolyte, reduces the contact resistance, and reduces the polarization of the electrode. This greatly improves the utilization rate of the active material of the electrode, the charging efficiency, and the discharge and output power of the battery.

 

Furthermore, the positive grid uses a combination of multiple alloys of multiple elements such as Pb-Ca-Sn-Al-Sb-Zn-Cd, while the negative grid uses lead-calcium-tin-aluminum high hydrogen overpotential materials. Such a design not only improves the capacity and life of the battery, but also ensures that the lead-tin multi-element alloy collector has the characteristics of small internal resistance and corrosion resistance, and can withstand long-term floating charge use.

 

In addition, by adopting new technologies and improving the grid material formula, the creep resistance and corrosion resistance of the colloidal lead-acid battery have been significantly improved. At the same time, the use of low-resistance porous PE separators and the rich liquid space designed in the plate ensure that the acid does not overflow, pollute the environment, or corrode equipment parts during the operation of the battery, and can smoothly absorb the gas cathode. These improvement measures further extend the life of the battery.

(VI) The battery shell cover adopts a labyrinth-type specially designed breathable valve, combined with special additives, which effectively reduces the loss of water.

(VII) By properly using additives, the normal charging state of the negative electrode can be maintained, the negative electrode sulfidation can be prevented, and the negative electrode self-discharge can be reduced. This not only ensures the stable charging of the negative electrode, but also reduces the polarization potential of the positive electrode, thereby slowing down the corrosion of the positive grid and further extending the service life of the battery.

 

Next, we will explore the development history and current status of photovoltaic power generation. Since the birth of the first practical photovoltaic cell in 1954, solar photovoltaic power generation has made significant progress. Although its development speed is slightly slower than that of computers and fiber-optic communications, the growing demand for energy and the limitations of conventional energy have gradually attracted attention to photovoltaic power generation. In particular, the oil crisis in 1973 and the environmental pollution problems in the 1990s promoted the rapid development of photovoltaic power generation technology. Its development process can be summarized into the following stages:
In 1893, French scientist Becquerel discovered the "photovoltaic effect", laying the foundation for the development of photovoltaic technology. Subsequently, Adams and others discovered the solid-state photovoltaic effect on metals and selenium sheets in 1876, opening a new chapter in photovoltaic technology. In 1883, the first "selenium photocell" was made and used as a sensitive device in various fields.

 

Entering the 20th century, photovoltaic technology has made significant progress. In 1930, Schottky proposed the "photovoltaic effect" theory of Cu2O barrier, which provided important support for later research. In the same year, Langer first proposed to use the "photovoltaic effect" to manufacture "solar cells" to achieve the conversion of solar energy into electrical energy.

 

With the deepening of research, the efficiency of photovoltaic cells has been continuously improved. In 1954, Chabin and Pirson successfully made practical single-crystal solar cells at Bell Laboratories in the United States, with an efficiency of 6%, which marked that photovoltaic technology has entered a new stage of development. In the same year, Wecker discovered the photovoltaic effect of gallium arsenide and made thin-film solar cells, further promoting the development of technology.

 

Subsequently, countries have devoted themselves to the research and development of photovoltaic technology. In 1958, solar cells were used in space for the first time, equipped with the power supply of the American Pioneer 1 satellite, showing its broad application prospects. With the birth of polycrystalline silicon solar cells and the grid-connected operation of silicon solar cells, photovoltaic technology has gradually become a reliable energy solution.

 

After entering the 1990s, photovoltaic technology has made breakthrough progress. The photoelectric conversion efficiency of gallium arsenide solar cells has reached 13%, and the efficiency of thin-film cadmium sulfide solar cells has also reached 8%. In addition, the successful development of ultraviolet cells and back field cells has further improved the efficiency and application scope of photovoltaic cells.

 

As the world's pursuit of renewable energy becomes increasingly urgent, photovoltaic technology has become a hot topic of research. Countries have proposed photovoltaic roof plans and development goals to promote the widespread application of photovoltaic technology. After 1997, the United States, Japan, and the European Union have all proposed grand photovoltaic development plans, indicating that photovoltaic technology is about to usher in a new stage of development.

 

At present, the application of photovoltaic technology has become more and more extensive, not only playing an important role in the power field, but also providing clean and efficient energy solutions for transportation, construction and other fields. Looking to the future, photovoltaic technology is expected to occupy a more important position in the global energy field and make greater contributions to the sustainable development of mankind.