Solar photovoltaic knowledge

1. What is photovoltaic?

In 1839, Becquerel in France discovered for the first time that under light conditions, there are voltages at both ends of some solid systems, and the two ends are connected by wires, and there will be current output. This is the photovoltaic effect (PV).

In 1954, Bell Lab Chapin et al. Developed a single-product silicon solar ground with an efficiency of 6%, and modern silicon solar power time began.

The realization of solar photovoltaic is to use solar panels made of silicon and other semiconductors to generate direct current using light. Since 1958, the solar photovoltaic effect was first applied in the field of space satellite power supply in the form of solar power. Today, it ranges from the power supply of automatic parking meters and rooftop solar panels to large-scale solar power centers , Its application in power generation has spread all over the world.

Photovoltaic technology has many advantages:

1. There are no mechanical moving parts;

2. Except for sunshine, no other fuel is required;

3. Can work in direct sunlight and under brother

4. At the same time, solar modules do not require maintenance, and operating costs are minimized;

5. The location is convenient and flexible, and roofs and open spaces in the city can be used.

Second, the type of photovoltaic

1. Monocrystalline photovoltaic products

◆ The main methods of silicon single crystal growth are czmethod and fzmethod. Single crystal products are widely used in our lives:

1. Semiconductor devices-from our computers and mobile phones to our electric toys, the core control parts are chips made of monocrystalline silicon products;

2. Photovoltaics-The initially developed photovoltaic products were mainly monocrystalline photovoltaics, which had good stability and power generation efficiency

◆ Single crystal photovoltaic products-single crystal rods are drawn by the Czochralski method or zone melting method (currently the Czochralski single crystal is mainly used for photovoltaics), and then sliced into silicon wafers (Jinke Energy, a leading photovoltaic manufacturing company in our city The crystal growth and slicing industry ranks first in the world) Then the battery is made by the battery process, and then packaged into the final component

◆ Advantages—good stability and high power generation;

◆ Disadvantages-the scale effect is relatively weak, the cost is relatively high

2. Polycrystalline photovoltaic products

◆ Polycrystalline photovoltaic products-polycrystalline silicon ingots are made by directional solidification method (dssmethod), then sliced into silicon wafers, and then made into batteries by battery technology, and then encapsulated into final components.

◆ At present, the amount of polysilicon ingots produced in the industry reaches 600KG, 800KG and 1200KG respectively

◆ Advantages: Large output and low cost.

◆ Disadvantages: The conversion efficiency is slightly lower than that of monocrystalline silicon photovoltaic products

3. Thin-film solar products

◆ Thin-film solar photovoltaic products——Thin-film solar cells are divided into hard and flexible substrates according to the substrate. By making a very thin (um order) thin film on the substrate, the thin film layer is used to generate electricity product.

Compared with single polycrystalline photovoltaic products:

◆ Advantages——Light weight, foldable and not easy to break.

◆ Disadvantages-First, the conversion efficiency is low.

Third, the photovoltaic product manufacturing process

1. Monocrystalline photovoltaic solar modules

2. Polycrystalline photovoltaic solar modules

4. Application of photovoltaic power generation

1. Military

The military application leader, except for the well-known spaceships and satellites. It is also well used in field operations, because solar power has the advantages of relatively light weight, no need for special operation when using it, and inexhaustible advantages. The use of flexible solar cells can first ensure individual soldiers With better concealment of equipment, because the diesel generator now used is easy to emit infrared rays and noise. As a kind of energy source supplement, photovoltaic products greatly enhance the emergency communication and survivability of individual soldier communication equipment, as well as the mobility and concealment of individual soldiers.

2. Civil

Photovoltaic power generation products are mainly used in three areas: one is to provide power for non-electricity occasions; the second is solar daily electronic products, such as various types of solar chargers, solar street lights and various solar lawn lamps; the third is grid-connected power generation, By 2009, China's grid-connected power generation has not yet begun to be fully promoted. However, part of the electricity used by the Beijing Games in 2008 was provided by solar power and district power generation. Since 2013, China's photovoltaic power generation has added new installed capacity for three consecutive years More than 10 million kilowatts; as of the end of 2015, the cumulative installed capacity of photovoltaic power generation reached about 43 million kilowatts, surpassing Germany and becoming the world's first. As of the end of 2016, the newly installed capacity of photovoltaic power generation in China was 34.54 million kilowatts, and the cumulative installed capacity was 77.42 million kilowatts. Both the new and cumulative installed capacity were the first in the world.

Advantages of photovoltaic solar power plants:

1. No danger of exhaustion;

2. Safe and reliable, no noise, no pollution, absolutely clean (no pollution);

3. Not limited by resource distribution area, can take advantage of building roof

4. No need to consume materials and set up transmission lines to generate electricity on the spot

5. High energy quality;

6. Users are easily accepted emotionally;

7. The construction period is short and the time it takes to obtain energy is short.