Solar panels
Solar panels are an essential component of a solar power system. They are made up of photovoltaic (PV) modules consisting of interconnected solar cells. Solar panels play the role of collecting energy from sunlight and converting it into electricity.
Solar cells are special devices with the ability to directly convert sunlight into electricity through the photovoltaic effect. These cells are often made of semiconductor materials like silicon and can generate direct current (DC) when exposed to light. When combined together in PV modules, they form solar panels, enhancing the efficiency of converting solar energy into electricity.
Solar panels have various applications, from commercial use such as providing electricity for buildings, commercial establishments, and warehouses, to residential use like supplying power to homes and household appliances. They are a renewable and environmentally-friendly energy source, helping reduce dependence on fossil fuels and mitigating environmental pollution caused by emissions.
Together with other components like inverters and storage batteries, solar panels form a complete solar power system, enabling us to efficiently harness solar energy to meet society’s electricity needs.
Structure and Operating Principle: Solar panels
Solar panels rely on the photovoltaic effect to convert solar energy into electrical energy. The main components include:
- Front Glass Layer: This is the heaviest component of the solar panel, with a thickness of 2-4mm, and serves as a tempered glass to ensure durability and protection for the entire panel, especially the solar cells inside. The glass layer must be transparent to transmit the full spectrum of light.
- Photovoltaic Cells: This is the core component of the panel responsible for absorbing sunlight and generating electrical energy.
There are several common types of solar panels used in the current market in our country: Polycrystalline and Monocrystalline solar cells. Additionally, there is the latest type known as Thin-Film Solar Cells, which are also applied in some electrical and electronic devices.
- Backsheet: Placed at the back, it is typically a white layer made of plastic that acts as an electrical insulator and protects the PV cells from moisture and weather conditions, thus enhancing the panel’s durability and performance.
- Junction Box: Located at the rear of the solar panel, it acts as the output interface. External connections for most photovoltaic modules use MC4 connectors to easily connect with the rest of the system.
- Frame: The frame is made of metal, usually aluminum, to ensure lightweight and durability. It provides structural support and protection for the entire solar panel assembly.
The combination of these components allows solar panels to harness sunlight and convert it into usable electrical energy, contributing to clean and sustainable energy production.
Characteristics of Solar Panels:
- Solar panels are designed to be compact and thin, typically in square or upright rectangular shapes. They come in black color (often Mono panels) or blue color (usually Poly panels), which adds to their aesthetic appeal, with white gaps between the solar cells.
- In terms of efficiency, Mono panels tend to have higher quality and conversion rates but come with a higher cost compared to Poly panels.
- They operate continuously and maintain high efficiency even under low light conditions.
- Solar panels are high-quality products capable of self-cleaning and adapt well to all weather conditions without compromising their power output.
- Designed with high waterproof and dustproof capabilities, they are suitable for long-term use, lasting for several decades.
Solar panels maximize the absorption of sunlight to serve various purposes, from household to industrial applications.
Where to Buy High-Quality and Affordable Solar Panels?
If you are looking for a reliable and reputable place to purchase solar panels with high quality and competitive prices, look no further than BINHANSHOP. We ensure to provide everything you desire:
- We offer wholesale and retail options for large quantities at competitive prices for customers involved in installations, dealers, distributors nationwide.
- We supply solar panels from top leading brands like Longi, Canadian, AE Solar, Jinko Solar, and more.
- Our range includes various power levels and sizes, from small mini panels like 40W, 50W, 60W, 100W, 150W to larger ones with capacities of 400W, 435W, 445W, 450W, 455W, 530W, 535Wp, 565Wp, 570Wp, and beyond.
- Our team of knowledgeable and enthusiastic staff provides the best services and assistance, catering to each customer’s specific needs and requirements.
- We offer product warranties of up to 12 years, with performance warranties lasting up to 25 years.
- Our services extend to solar installations for projects of all sizes, catering to households, businesses, and enterprises.
At BINHANSHOP, you can trust us to deliver quality products and services, making your solar energy journey a seamless and satisfying experience.
The Most Important Criteria for Choosing the Right Solar Panel:
Given that solar panels can reliably produce electricity for up to 25 years, it is crucial to carefully consider high-quality and efficient options when making a purchase.
To objectively select suitable types of solar panels, relying solely on a datasheet may not always be sufficient, as they contain different information depending on the manufacturer.
The most critical quality criteria for choosing the right solar panel are as follows:
- Quality: Ensure there are no uneven or film residues on the solar cells, and they are correctly positioned. These imperfections should not occur during the manufacturing process. When making a purchase, it’s essential to inspect the surface of the solar panels to ensure proper handling.
- Warranty: There are two types of warranties for photovoltaic panels:a. Performance Warranty: This warranty covers the degradation of the solar module’s performance over time due to aging. The degree of performance degradation varies depending on the type of solar cell.Manufacturers offer warranties that guarantee their solar panels will achieve a certain percentage of the rated power after 20 or 25 years. For example, 90% within the first decade and 80% within 25 years.
b. Product Warranty: This warranty covers potential module defects and is typically provided for 10 to 12 years.
- Certifications: Solar panel manufacturers should have the following certifications:a. IEC61215 Testing Certificate for crystalline modules: IEC61215 covers the parameters related to the aging of solar panels, including:
- Solar irradiance, including UV rays.
- Climate variations (cold, warm, humid).
- Mechanical loads (hail, wind suction, wind pressure, snow).
The standard load capacity is 2400 Pa, but if installed in areas with heavy snowfall, it should be 5400 Pa.
b. IEC 61646 Testing Certificate for thin-film PV modules: This is similar to IEC 61215 testing, but it includes additional tests related to the behavior of amorphous silicon concerning temperature and radiation.
c. IEC61730 / EN61730 Safety Certifications: This certification has two parts:
- The first part specifies all construction requirements and mandatory design characteristics of the solar panels.
- The second part includes requirements for testing and classifying three different application classes for solarpanel designs, indicating their intended use, relevant quality tests, and safety class modifications.
- Efficiency: Efficiency represents the percentage of solar radiation that the photovoltaic cells can convert into electrical energy.
The spacing between photovoltaic cells in solar panels makes the efficiency of individual cells higher than that of the entire panel.
Generally, crystalline modules have an efficiency range of 15% to 19%, but some reputable brands like Jinko, Longi, Canadian have achieved efficiencies above 20%. The efficiency of solarpanels is continuously improving as a competitive factor among manufacturers.
Based on the current market efficiency (subject to change), the following four classification ranges can be used to assess solar panel efficiency:
a. Economic Efficiency Range: Efficiency below 15% (Polycrystalline panels, thin-film panels). b. Standard Efficiency Range: Efficiency from 15% to 17% (Average polycrystalline, thin-film panels). c. Good Efficiency Range: Efficiency from 17% to 20% (Good polycrystalline, average monocrystalline panels). d. Excellent Efficiency Range: Efficiency above 20% (Excellent monocrystalline panels).
- Rated Power / Power Tolerance: The rated power of a solarpanel represents its maximum output and is measured in watts peak (Wp). The rated power is specified by the manufacturer.
Due to the uniqueness of each PV module resulting from the production process, there is a certain power tolerance called the power tolerance range. Typically, this range is from -5% to +5%.
Solar panels supply this rated power under Standard Test Conditions (STC), meaning direct sunlight perpendicular to the panel’s surface with an irradiance of 1000W/m², an air mass coefficient of 1.5, and a cell temperature of 25°C.
- Low Light and Temperature Behavior: In addition to the rated power, information about a panel’s performance under low light and high-temperature conditions is crucial.
Datasheets can provide insight into a panel’s behavior. The temperature coefficient indicates how the current and power increase by a percentage while the voltage decreases.
A lower temperature coefficient (around -0.4% to -0.5%) is better, and even lower for thin-film modules. A temperature coefficient (P MAX) close to 0 is desirable. All PV panels lose power as they heat up. The “Pmax temperature coefficient” tells us how much power is lost per °C that the solar panel is hotter than 25°C.
- Glass Thickness: The thickness of the glass contributes to the stability of the solarpanel. Panels with 4mm-thick glass are preferable to those with 3mm-thick glass.
Even the fixing of a panel inside the glass improves electricity yield when light is incident obliquely.
Tempered glass is more robust and safer than standard glass. If it breaks, it will shatter into thousands of small pieces without causing harm. Both strength and safety are essential for solar panels.
Most glass contains iron impurities in the form of iron salts in silicon oxide, which reduces light transmission through the material.
Compared to other transparent glass types, low-iron glass’s main advantage is that it contains reduced iron content, improving light transmission.
Applying an anti-reflective coating on the glass surface increases the effective utilization of solar radiation for electricity generation.
- Junction Box: When the junction box of a solarpanel is located at the rear, the adhesion area should be small. Otherwise, heat can accumulate, leading to a decrease in photovoltaic cell efficiency.
- Frame: Solar panels come with a frame on each side. Care should be taken to avoid any dirt accumulation. Frameless panels do not encounter this issue and often have better cooling.
The frame should be made of anodized aluminum to enhance corrosion resistance and assembly stability.
- Manufacturer’s Origin: Manufacturers from Germany, Japan, and the USA are reputable and can be included in the list of choices.
There are many well-established manufacturers offering high-quality solar panels. However, many new companies are emerging in the market.
You can choose from other well-known manufacturers in the Vietnamese market.
Types of Solar Panels:
Different types of solar panels have distinct advantages depending on the photovoltaic cells used.
- Monocrystalline: Monocrystalline panels have the highest efficiency. Compared to monocrystalline, polycrystalline solar panels have a shorter lifespan and are cheaper.
- Polycrystalline: Polycrystalline solarpanels are less expensive and have a shorter payback period compared to monocrystalline panels.
- Thin-Film: Thin-film solar panels are lightweight and suitable for installation on flat roofs. They also perform better under low-light conditions compared to crystalline panels. (However, this type is not widely used in our country.)
Manufacturer’s Experience:
Consider the following when choosing a solar panel manufacturer:
- How long has the manufacturer been in the industry?
- Is the product a new one, yet to be tested?
- Are there any particularly positive or negative reviews about the manufacturer of the solarpanels, such as feedback on warranty claims and handling?
Solar Panel Size:
When selecting solarpanels, the dimensions (length x width) play a crucial role. They should be chosen to optimize the available roof area.
Weight:
For the static load on the roof, the weight of the solar panels is the most critical factor.
For roofs with low load reserves, lightweight panels such as thin-film panels should be used.
Price-to-Performance Ratio:
Some high-performance solar panels generate better yields compared to standard panels. Manufacturers of these modules tend to have higher prices.
The cost of solarpanels should not be the sole criterion when making a decision; calculations and comparisons should be made with the rates of other types of modules to determine whether it is reasonable to pay the additional cost over a certain period of use in a specific solar power system.
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