Development trend of photovoltaic technology

 

 

Energy structure transformation is key to achieving carbon neutrality. Photovoltaics are both sustainable and clean.

 

With the rapid growth of energy storage facilities, the instability brought by photovoltaic power generation connected to the power system has been suppressed, and the photovoltaic energy storage mode has developed rapidly.

1. The trend of energy structure transformation is clear

● Technical level

Competition among manufacturers intensifies. Benefiting from the support policies of previous years, photovoltaic demand is strong. Top 10 photovoltaic battery companies in the world continue to expand production capacity, and the scale effect is obvious.

At the same time, with the influx of new entrants, competition began to intensify. PV manufacturers must continue to research cost reduction and efficiency improvements to improve market competitiveness. The technical routes of the four major links of photovoltaic silicon materials, silicon wafers, cells and modules are all upgraded in the direction of high conversion efficiency and low cost.

● Price side

Technology-driven price reduction Looking back at the development history of China's photovoltaic industry, with the selection and upgrading of photovoltaic technology, the cost of all links of the industrial chain has decreased significantly, and China's photovoltaic industry has changed from policy-driven to economic-driven.

With the advancement of photovoltaic technology and the sharp decline in electricity costs, coupled with the demand for energy structure transformation, China is expected to add 113.7GW of photovoltaic installed capacity in 2023, an increase of 30.1% year-on-year.

Among them, 45.2GW of centralized photovoltaic installed capacity and 68.6GW of new distributed photovoltaic installed capacity were added. It is expected that 321.6GW of new PV capacity will be added globally in 2023, an increase of 20.0% year-on-year. Among them, 182.8GW of centralized photovoltaic installed capacity and 138.8G of distributed photovoltaic installed capacity were added.

The trend of energy structure transformation is clear

 

It is estimated that by 2025, China's cumulative photovoltaic capacity will be 848.1GW, and the global cumulative installed photovoltaic capacity will be 2528.6GW. Energy structure transformation is the key to achieving carbon neutrality.

In terms of emissions mix, switching power generation from fossil fuels to clean energy is the largest contributor to global emissions reductions, accounting for half of all emissions reductions from 2022 to 2050. This includes replacing undiminished fossil fuels with wind, solar, other renewables and nuclear.

Electrification of transport and industrial processes, buildings and heating was the next largest contributor, reducing total emissions by about a quarter during this period. Hydrogen is also a significant contributor, albeit to a much smaller extent, accounting for 6% of emissions reductions.

2. With the rapid development of energy storage mode

The solar photovoltaic is both sustainable and clean, and have higher development potential than other renewable energy sources. Among them, hydropower has high efficiency and low cost, but the construction of hydropower stations has great damage to the ecological environment, and the destruction of land and vegetation will also cause high carbon emissions.

The advantage of nuclear power plants is that they can generate stable power all year round and night, but nuclear power plants have potential safety hazards and nuclear waste disposal is also troublesome. Thermal power generation is highly resource dependent and has carbon emissions.

Wind and solar are two of the fastest declining and most widely used renewable energy sources. The disadvantages of wind energy over solar energy are mainly due to the requirements of geographical location, and wind power generation is required to be in places with abundant wind resources. The geographical scope of solar power generation is much larger, whether it is between urban buildings or in the vast desert.

With the rapid development of energy storage mode

 

The rapid growth of energy storage facilities has eased the instability caused by photovoltaic power generation connected to the power system. Solar power generation is greatly affected by the natural environment, intraday output fluctuates greatly, and because weather is difficult to predict, photovoltaic output is even more difficult to predict.

At present, the existing power systems are designed for thermal power-based power systems, and the large-scale integration of photovoltaic with large output fluctuations will affect the reliability of the power system. Original flexible resources such as backup power systems for thermal power will not be able to cope with the complex situation in the future, and the difficulty of regulating the power system will increase significantly.

Energy storage can effectively improve ability of the power grid to accept clean energy and solve the problem of grid security and stability caused by large-scale clean energy access. With the increase of energy storage facilities, this problem of photovoltaic power generation can be gradually improved.

The integration of photo storage can realize 24-hour power generation in photovoltaic power plants, and the mode develops rapidly. Photovoltaic power generation is subject to sunlight, and the power station is connected to the energy storage systems to store excess electricity during the day for night use, which can produce 24-hour power generation of photovoltaic power plants.

3. Technical route is gradually becoming clear

● Industrial development revolves around four main links

The photovoltaic industry chain includes three parts: main links, auxiliary materials and equipment, and the development and changes of the industrial chain mainly revolve around four major links: silicon materials, silicon wafers, cells and modules.

China's technical route is gradually becoming clear

  • Polysilicon

It is a non-metallic material purified by a series of physical and chemical reactions with industrial silicon as raw material, and belongs to the basic material of photovoltaic products.

  • Silicon chip

It is a prismatic sheet formed by cutting single crystal silicon rods or polycrystalline silicon, and is currently dominated by single crystal silicon wafers.

  • Cells

It is a semiconductor sheet that uses the photovoltaic effect to form a PN junction by diffusion of semiconductor materials such as silicon wafers as a substrate, thereby using the photovoltaic effect to convert photoelectricity.

  • Subassembly

It is a terminal product that is connected and packaged in series and parallel by a certain number of battery cells through wires, and can output direct current separately.

Since 2011, Chinese companies have developed rapidly, and the four major links have occupied a leading position in the world. Benefiting from the support policies of previous years, photovoltaic demand is strong. According to statistics, in 2022, Chinese companies occupy a leading position in the global shipments of polysilicon, silicon wafers, cells and modules.

4. Industry technology is constantly escalating

Multi-dimensional monocrystals have advantages to help monocrystals occupy the market. At present, the photovoltaic industry is mainly divided into two crystalline silicon technology routes: monocrystalline and polycrystalline.

● From the view of material properties

The cell conversion efficiency of monocrystalline is higher than that of polycrystalline, and the mass production conversion efficiency of polycrystalline is generally 18%-20%, while the mass production conversion efficiency of monocrystalline is generally not less than 20%.

Industry technology is constantly escalating

 

● Cost perspective

The cutting cost and battery cost of monocrystals are lower than that of multi-products, and the overall cost of single products performs better, so the current market is dominated by monocrystals. Large silicon wafers can effectively reduce the cost of non-silicon per watt, and large silicon wafers are irreversible.

Cell technology is flourishing and upgrading towards high conversion efficiency and low cost. The existing cell technologies mainly include P-Perc, N-Topcon, HJT, IBC and perovskite, etc., and the technology upgrade direction is mainly towards high conversion efficiency and low cost.

Component packaging technology has changed from full chip to half chip. Thinning technology reduces internal circuitry and friction, and improves package efficiency. In addition, the operating temperature of the component is reduced, which reduces the chance of hot spots, and improves the reliability and safety of the components.

5. Conclusion

This matching mode can greatly reduce the cost of electricity, driving the rapid rise in photovoltaic installed demand. In the era of parity, the installed capacity of various countries has entered a period of rapid growth. With the advancement of photovoltaic technology and the significant reduction in the cost of electricity, the need for energy structure transformation is superimposed.

 

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