On August 16, the "2024 TOPCon Solar Cell Technology Development Trend Seminar" was held in Shanghai. The conference was hosted by the China Photovoltaic Industry Association, and invited industry authorities, research institutions, photovoltaic power design institutes, and representatives of photovoltaic companies to deeply analyze the development trends and paths of TOPCon technology, and further promote the original innovation and application of battery technology. Dr. Ouyang Zi, Chief Technology Officer of JA Solar Technology, was invited to attend the meeting and held dialogues with several CTOs of TOPCon industrialization leading companies to jointly interpret the underlying advantages and future forms of TOPCon technology.

Ouyang Zi said that a third-party report showed that the overall TOPCon capacity, including the capacity under construction, is expected to approach 900GW, which is enough to meet most of the market demand in the next five years; at the same time, the report predicts that the market share of TOPCon technology based on the estimated shipment volume of TOPCon modules will remain at around 70%-80% in the next five years.

There are two underlying advantages that have made TOPCon technology the absolute mainstream of the photovoltaic panel industry. On the one hand, theoretically speaking, the key factors that need to be considered in battery design are the balance between light absorption, passivation, and multi-carrier transmission. As far as the currently known field is concerned, the system of contact passivation plus poly is the optimal mass production solution, and the TOPCon technology route itself is excellent enough.

On the other hand, the development of photovoltaic mass production technology is a combination of "process + equipment + material". From PERC to TOPCon, the overall change in manufacturing process and equipment does not exceed 30%, but it can greatly improve the conversion efficiency, and the cost performance is extremely high. After conquering key technologies such as boron diffusion and poly deposition, the rapid development of TOPCon became a matter of course, and it naturally became the first choice for leading companies.

At present, the industry should have a consensus on the mainstream status of TOPCon technology for about five years. TOPCon technology is not static. The introduction of new equipment and new materials, the optimization of battery structure and process can all enable the battery efficiency to be continuously improved. For example, metallization, as a key step from battery to component, is very important. As a high-temperature system, TOPCon has more metallization paths to choose from than heterojunction, and has greater potential for innovation and efficiency improvement.

Compared with BC, TOPCon is more suitable as the bottom cell of the stacked cell. In the more distant future, the "TOPCon+perovskite" stacked cell may lead the industry into the era of mass production of "30%+efficiency", and its vitality may far exceed five years.

For example, in July this year, in the "Solar Cell Efficiency Record Table" led by Professor Martin Green of the University of New South Wales, Australia, JA Solar Technology topped the "Mass Production Size TOPCon Cell Efficiency Category" with its mass production cell size, breaking the world record. This record was included in the certification results of the Hamelin Institute for Solar Energy Research (ISFH) in Germany.

Today, ISFH has given the latest efficiency certification results for JA Solar Technology's mass production size cells. This result is further improved compared to the previous certification efficiency. It has been included in the "2024 Solar Cell China Highest Efficiency" record by the Photovoltaic Committee of the China Renewable Energy Society. The efficiency breakthrough of mass production size cells is the most difficult. JA Solar Technology continues to create new records in mass production size cells, which is not only a reflection of its own R&D strength, but also proves the growth potential of TOPCon technology.

In addition, TOPCon technology is still a more suitable technical route for full-scene applications. At present, the global annual installed capacity of photovoltaic power generation has reached hundreds of gigawatts, and the market is increasingly focusing on diverse solutions for different scenarios. It is no longer possible to "cure all diseases with one good prescription". Based on the high efficiency and low cost brought by the scale effect of the TOPCon technology industry, products can achieve rapid response and iteration for different application scenarios. For example, JA Solar Technology has launched corresponding component solutions based on TOPCon technology products for different climate conditions such as deserts, hot and humid weather, plateaus and extreme cold. On the other hand, JA Solar also provides customized products based on TOPCon technology for different regions and scenarios, such as pile-based and floating offshore photovoltaic solutions, single-glass and anti-dust roof photovoltaic solutions, and anti-glare solutions, etc., to meet different market needs.

How to choose a solar power generation system that suits you

 

First, you need to understand your energy needs.

A solar power generation system should be able to meet the electricity needs of your home or business.

Therefore, before choosing a solar power generation system, customers need to clarify their electricity consumption and electricity consumption time. You can get this information by checking your electricity bill or using electricity monitoring equipment. In addition, you need to consider the future growth trend of electricity consumption to ensure that the selected solar power generation system can meet your needs in the long run.

 

Second, you need to understand the roof installation conditions or ground installation conditions.

Solar power generation systems usually need to be installed on the roof (or open ground).

Therefore, roof conditions are one of the important factors in choosing a solar power generation system.

1. You need to determine the area and orientation of the roof. Generally speaking, a south-facing roof is the most ideal choice because it can receive the most sunlight.

2. You need to consider the load-bearing capacity of the roof to ensure that the installation of the solar power generation system will not cause damage to the roof structure.

3. You need to consider whether there are trees or buildings on the roof to ensure that the solar panels can fully receive sunlight.

 

Third, you need to consider the budget and return.

The installation and maintenance costs of the solar power generation system are one of the important considerations for selection.

1. You need to consider the initial investment of installing a solar power generation system, which includes the price of solar panels, inverters, batteries and other equipment as well as the installation costs.

2. You need to consider the operation and maintenance costs of the solar power generation system, such as replacing batteries, equipment maintenance, and cleaning of solar panels.

3. You need to calculate the payback period of the solar power generation system. Given that the price of solar power systems is relatively low now, the investment payback period has been greatly reduced.

 

Fourth, you need to consider the reliability and quality of the solar power generation system.

Choosing a reliable solar power generation system can ensure its long-term stable operation and reduce the cost of maintenance and replacement.

 

In short, choosing hopelightsolar solar power generation system that suits you needs to consider many aspects, including energy needs, roof conditions, budget and payback, and the design reliability and quality of the system.

Taking these into consideration, you can choose the photovoltaic system that best suits you and reduce your energy costs.

There are many factors that affect the power generation and efficiency of a solar station with the same capacity. Today SAIL SOLAR will lead you to have a studying.

 

1. Solar Radiation

When the conversion efficiency of solar panel is constant, the power generation of the solar system is determined by the intensity of solar radiation. Normally, the utilization efficiency of solar radiation by solar systems is only about 10%. Therefore, solar radiation intensity, spectral characteristics, and climate conditions must be taken into consideration. If the current year's power generation exceeds or falls short of the standard, it is likely that the overall solar radiation for that year deviates from the average.

 

 2. Tilt angle of solar panel

The azimuth angle of solar panel is generally selected in the south direction to maximize the power generation per unit capacity of solar station.

As long as it is within ±20° of due south, it will not have much impact on the power generation. If conditions permit, it should be as far as 20° to the southwest.

The above angle recommendations are based on installation in the Northern Hemisphere, and vice versa for the Southern Hemisphere.

Tilt angles vary from place to place, and local installers are more familiar with the optimal tilt angle for components. If it is a pitched roof, in order to save brackets, many of them will be laid flat on the roof, regardless of the tilt angle, for the sake of beauty.

 

3. Solar panel efficiency and quality

There are many solar panel types to choose from on the market, such as polycrystalline silicon, monocrystalline silicon solar panel, etc. Different solar panels have different power generation efficiency, attenuation and quality.

 

The most important thing is must purchase them from regular channels at a reasonable market price. Only in this way can you ensure stable and reliable power generation for 25 years.

 

4. Solar panel matching loss

Any series connection will cause current loss due to the current difference of solar panels, and any parallel connection will cause voltage loss due to the voltage difference of solar panels. Losses may reach more than 8%.

 

In order to reduce the matching loss and increase the power generation capacity of the solar  station, we should pay attention to the following aspects:

1)To reduce matching losses, try to use solar panels with consistent current in series;

2)The attenuation of solar panels should be kept as consistent as possible;

3)Isolation diode.

 

5. Temperature (ventilation)

Data shows that when the temperature rises by 1°C, the output power of crystalline silicon solar panel decreases by 0.04%. Therefore, it is necessary to avoid the impact of temperature on power generation and maintain good ventilation conditions for the solar panels. 

 

6. Effect of dust

The crystalline silicon solar panel is made of tempered glass. If it is exposed to the air for a long time, organic matter and a large amount of dust will naturally accumulate. Dust falling on the surface blocks the light, which will reduce the output efficiency of the solar panels and directly affect the power generation. At the same time, it may also cause a "hot spot" effect on the solar panels, causing damage to the components. solar panel station must be cleaned in time.

 

7.Shadows, snow cover

During the site selection process of the solar solution, attention must be paid to the light shielding. Avoid areas where light may be blocked. According to the circuit principle, when solar panels are connected in series, the current is determined by the smallest solar panels Therefore, if there is a shadow on one solar panels, it will affect the power generation of this solar panels. Therefore, when installing a solar power station, you must not be greedy for large capacity. You must consider the area of the roof and whether there is any obstruction around the roof.

 

8. Maximum output power tracking (MPPT)

MPPT efficiency is a key factor in determining the power generation of solar inverters, and its importance far exceeds the efficiency of the solar inverter itself. MPPT efficiency is equal to hardware efficiency times software efficiency. Hardware efficiency is mainly determined by the accuracy of the current sensor and the accuracy of the sampling circuit; software efficiency is determined by the sampling frequency.

 

There are many ways to implement MPPT, but no matter which method is used, the solar panel power changes must first be measured and then react to the changes. The key component here is the current sensor. Its accuracy and linear error will directly determine the hard efficiency, and the sampling frequency of the software is also determined by the accuracy of the hardware.

 

9. Reduce line losses

In solar systems, cables account for a small part, but the impact of cables on power generation cannot be ignored. It is recommended that the line loss of the system's DC and AC loops be controlled within 5%. The cables in the system must be well prepared, including the insulation performance of the cable, the heat-resistant and flame-retardant performance of the cable, the moisture-proof and light-proof performance of the cable, the type of cable core, and the size and specification of the cable.

 

Therefore, in daily operation and maintenance, we need to check whether the lines are damaged and whether there is leakage or other conditions. Especially after every typhoon or hailstorm, it is essential to check whether the lines and connectors are loose.

 

10. Inverter efficiency

The solar inverter is the main component and important component of the solar system. In order to ensure the normal operation of the power station, the correct configuration and selection of the inverter is particularly important.

 

In addition to the various technical indicators of the entire solar power generation system and the product sample manual provided by the manufacturer, the configuration of the inverter generally needs to consider the following technical indicators: 1. Rated output power 2. Output voltage adjustment performance 3,Overall machine efficiency 4.Start-up performance.

 

There are not many daily environments that affect the efficiency of the inverter. Pay attention to installing the inverter in a cool place and keep the surroundings ventilated to facilitate the heat dissipation of the inverter. Especially in summer and autumn, normal heat dissipation can maintain the power generation efficiency of the inverter.