Learn about PV batteries

With the economic life of solar power projects of 25 years, the question is what to do to handle a large number of solar cells after the life of the project ends? This article aims to provide information to readers to understand and view the SUN PIN when considering it as waste (due to expiration or failure). This article is not intended to provide a solution to handle expired solar panels.

Currently, renewable energy plays an important role in supplementing and responding to a significant portion of the increasing human energy needs. This is an abundant resource, available in nature and exists in many common forms. Solar energy, which is an almost limitless energy source that can be exploited in most parts of the world, is emerging as an ideal complementary alternative to other traditional energy sources.

Solar power technology is currently developing rapidly. By the end of 2017, the total installed solar photovoltaic (PV) capacity in the world reached 402GW; In particular, China, the US and Japan are among the world’s largest solar PV installations with an estimated capacity of 130.5GW, 51GW and 49 GW respectively.

According to the Institute of Energy – Ministry of Industry and Trade, the potential of solar electric technology in Vietnam is about 1,677.5GW. Under a highly developed economic scenario, a total of 385.8 GW of solar power will be required by 2030 to serve economic development. According to the World Bank, the potential of solar roof power in Ho Chi Minh City is 6.3GW, Da Nang is 1.1GW. With such great potential, a number of negative information and opinions that are not true in nature can hinder the development of solar power in Vietnam.

Many people said that expired solar batteries will become hazardous waste for the environment and need to be treated. So why is the expired solar battery considered hazardous waste?

With the economic life of solar power projects of 25 years, the question is what to do to handle a large number of solar cells after the life of the project ends?

This article aims to provide information to readers to understand and view the SUN PIN when considering it as waste (due to expiration or failure). This article is not intended to provide a solution to handle expired solar panels.
Why is expired solar battery a hazardous waste? Is it mistaken to say that expired solar batteries are hazardous waste?

In order to answer these questions, first of all, we need to consider the key ingredients that make up the solar panels. What are the solar cells?
Composition of solar panels

Solar batteries or solar cells or photovoltaic cells (Solar panel / module) including many solar cells – are semiconductors containing on the surface a large number of light sensors is photodiode, which converts light energy into electrical energy.

Photovoltaic cells (solar cell)

Today, the main materials for solar cell are crystalline silicon (single crystal, polycrystalline) or thin silicon membrane.

Solar battery (solar panel)​

Photovoltaic cells (solar cell) is assembled into blocks to become solar battery (solar panel). Usually 60 or 72 photovoltaic cells on a solar panel.

Solar battery construction

Frame: Frame is made of aluminum.

Glass: Tempered glass / safety.

Encapsulant: is a thin film layer that helps to firmly link between solar cells (solar cell) and toughened glass / polymer backsheet to protect against impact and improve the life of solar cells. EVA is a kind of polymer material (Ethylene Vinyl Acetate Copolymer) combining Ethylene and Acetate and is produced by polymerization under very high pressure, widely used in garment, footwear and auxiliary industries. ….

Solar cell: are crystalline silicon sheets (single crystal, polycrystalline) or thin silicon membranes that are the main element of solar cells.

Backsheet: is a layer of protection on the underside of solar cells (solar cell) to avoid abrasion due to the environment. Most solar cell manufacturers use PVF (Polyvinyl fluoride) to make Backsheet. PVF is a polymer material mainly used in aircraft interior, raincoat …. Some more advanced batteries use the “Backsheet” layer with a double glass tempered glass.

Junction box: The case is usually a heat-resistant, fire-resistant, weather-resistant, UV-resistant polymer …. The connectors in the box are usually made of brass, covered with silver or covered with tin.

Wiring: link between solar cell (solar cell) and connect to electrical junction box. These conductors are made of copper or silver.

In the above mentioned components, toughened glass panels and photovoltaic cells are produced from sand with the main component of Silicon Oxide (SiO2) which is the material to produce common items in daily life. like a bottle of food containers …

The main mass of solar panels is from heavy to light order (1) Tempered glass sheet: ~ 65%; (2) Frame: ~ 20%; (3) Solar cell: 6% -8%; (4) the remaining ingredients. A solar cell with 72 cells normally has a mass of about 22-27kg, of which (1) + (2) + (3) accounts for about 92-94% of the total solar panel.


b. Is it mistaken to say that expired solar batteries are hazardous waste?

It can be seen that the main constituents of solar cells do not contain hazardous substances. So why is there so much information saying that expired solar cells will become hazardous waste and need to be treated?

Perhaps this inaccurate judgment stems from the name of the solar power “PIN” in Vietnamese or its structure with the word “CELL” in English.

When it comes to the word “PIN” (Vietnameseized from “PILE” in Vietnamese), people immediately think of common types of charged PIN. Since the French colonial period, flashlights, battery-operated radio (radio) are popular items of the French, wealthy aristocrats and landlords in Vietnam. Vietnamese people in the twentieth century were very familiar with the brand “Con O” and “Con Rabbit” batteries. Today many foreign battery firms penetrate and make up the majority of Vietnam’s battery market share.

Ancient flashlight and Pin Eagle

This “PIN” word in French is “PILE”, in English “BATTERY” or “ACCU” in French.

“BATTERY” or “ACCU” is a chemical storage device, when it is mentioned, people immediately think of “BATTERY” of lead acid.

All PINs for the purpose of using the same charge as a flashlight or battery when discharged are considered to be hazardous waste and therefore need to be recovered for disposal.

Therefore, when it comes to PINs, people think of hazardous waste immediately, so the solar PIN becomes the victim of this naming (“SUN BATTERY”).

So why is it called “SUN PIN” without using another name without the word “PIN”? Where does the name “SUN PIN” come from?

This question is really difficult to answer, but in the author’s opinion, it probably comes from the word “CELL”.

In everyday life today, when we buy / replace batteries for laptops, for some mobile phones … we often ask, “How many cells does this battery have?”, “4 cell 6 cell? ”…. This is a professional term to say the battery’s capacity in a simple way.




One type of laptop battery has 6 Cells.

The similarity of “PIN SUN” and “ELECTRIC VOLUME BATTERY” systems are as follows:


Constitutes a charged battery system

The structure of the battery sets also comes from the CELL with several volt voltages >> the CELL is put together into MODULE >> the MODULE is linked together into RACK >> and eventually becomes the SYSTEM (SYSTEM ) charged.

Components of PV solar battery system

For "PIN SUN" is similar: from the cell phone is CELL >> interconnected into MODULE / PANEL >> the MODULE is connected together into ARRAY / TABLE >> and finally becomes the SYSTEM SYSTEM (SYSTEM) solar energy.

Therefore, perhaps the naming of the word “PIN” for the solar power system comes from this similarity.

Research and assessments of countries around the world and solutions to deal with expired solar cell waste.

Therefore, in the opinion of the author of this article, “BATTERY” is not hazardous waste and is mistaken for naming. So the question is how do countries around the world look at this?

Regarding PV solar cell processing, please refer to the articles and some evaluation information:

+ According to SolarTech (USA):

The PV panel life span of 20-30 years, with solar panels from the 1970s and 1980s is still in use.

Many state and federal control agencies have conducted experiments to check their environmental hazards, but most products pass these tests and these agencies do not give PV solar cells. to control hazardous waste.

Measures for the expired panel: there are many different measures, but together it separates the components of the material that make up the panel (glass, cell, metal, plastic / polymer) for reuse, like aqua panels. When making bottles, cells are chemically treated so that reusable factories produce new cell panels for higher efficiency / efficiency …

Summary: According to SolarTech, in the US, for solar panels that are no longer used (due to expiration, failure …) are not considered hazardous waste but are resources to produce inputs for production. Export new solar batteries or for other purposes.

+ According to IEA Photovoltaic Power Systems Program – IEA PVPS (Switzerland): This organization has surveyed and researched the treatment of expired solar cells for a long time and in many countries. According to the publication of this organization:

Reaction and evaluation in the following countries:

– EU: there is a regulation on recycling / reuse of solar cells in the EU of 85% / 80%.

USA: There are currently no laws regulating panel PV management expired (No federal regulations currently exist in the United States regarding collection and recycling of end-life PV modules; therefore, the general country regulations regulations apply. ).

– Japan: There are no specific regulations on the treatment of expired solar cells, panels that must be disposed of (if no longer used) are treated like ordinary solid waste (not dengoures). In Japan these panels are also recycled for use.

– China and South Korea: there are similar assessments as above.

PV panel life lasts up to 30 years and most still continue to operate.

All materials that make up the solar panel are recovered and reused. The materials are considered to be resources, not hazardous waste.

The IEA PVPS document also provides information on processing technologies for recycling / reusing in different countries for different types of PVs. Countries have also been studying technologies for effective recycling, low cost, shorten recycling time …

From the above analysis and inquiry, we can identify and propose as follows:

+ There is confusion because naming solar power is “PIN”, leading to conflicting information that “SUN BATTERY” is hazardous waste.

+ The expired solar cell will not be a hazardous waste but a resource for re-use for the purpose of producing new solar cells with higher quality and cheaper price, in addition to used for other purposes.

+ Vietnam is considered a place with great potential for solar power development. Therefore, strong propaganda information is needed for people to properly understand the nature of solar cells and support the development of solar power in Vietnam.