Types of PV Panels

Since its invention in the mid-20th century, the PV panel industry has been booming as people seek a more efficient and eco-friendly way of electricity generation. Some of the biggest companies in the market include Jinko Solar panels and LONGI solar panels.

WHAT ARE PV PANELS? WHY SHOULD WE CARE?

With increasing concerns regarding global warming and climate change, scientists are prompted to explore different forms of renewable energy technology, including solar energy. Photovoltaic (PV) panels, also known more commonly as solar panels, use the Sun’s energy and convert it into electricity, providing an eco-friendly form of electricity generation. Different types of PV panels and their efficiency will be discussed further on in this article. PV cells are made from semiconductors with silicon being the most common. Individual PV cells are usually very small but when combined to form solar panels, they can be very efficient. When the Sun shines over these panels, the heat from the sunlight is absorbed, creating an electrical field causing electricity to flow.

TYPES OF SOLAR PV SYSTEMS

Before discussing the types of PV solar panels, let us talk about the different types of solar PV systems.

The three types of solar PV systems are:

• Grid-Connected or Utility-Interactive Systems
• Off-Grid Systems
• Hybrid Systems

A grid-connected PV system is one where the photovoltaic panels are connected to the utility grid through a power inverter unit, allowing them to operate in parallel with the electric utility grid. This type of solar PV system can be used with or without batteries, unlike off-grid solar PV systems, which require batteries. The advantage of using batteries includes more independence in the household.

Advantages of using a grid-connected system include that not only is it cheaper than other types of solar PV systems but it also offers design flexibility as the system does not need to power all of the household’s loads. The main drawback of a utility-interactive system is that it does not provide any outage protection.

Stand-Alone systems are also known as off-grid solar PV systems. Off-grid systems are not connected to the electricity grid; therefore, they require battery storage. Off-grid systems are designed in such a way that they generate enough energy to meet the home’s requirements, even in winters when there is less sunlight.

The high cost of batteries and off-grid inverters means off-grid PV systems are much more expensive than on-grid systems and so are mostly used in remote areas that are far from the electricity grid.

A hybrid solar PV system operates by sending Sun’s energy to an inverter, which, in return, sends electricity to power the electrical appliances. The extra energy that is not in use is stored in the batteries. The energy stored in batteries is then used to power the electrical when the solar panels are not producing energy. The advantages of a Hybrid solar PV system include low maintenance and optimal utilization of the renewable source.

TYPES OF PV PANELS

There are different types of PV solar panels. These types include monocrystalline, polycrystalline, and thin-film.

Crystalline photovoltaic cells are currently the most efficient form of solar photovoltaics, covering around 85 percent of the photovoltaic market. Crystalline photovoltaic panels are further divided into two types: monocrystalline and polycrystalline.

MONOCRYSTALLINE

Monocrystalline is identified as mono because single-crystal silicon allows electrons to produce electricity. The thickness of such wafers ranges from 200-400 μm. The cells being cut into a single source of silicon results in monocrystalline modules being the most efficient of the different module types. Such modules have a high-power output and efficiency of around 20 percent. Advantages of such modules include that they have the least space and last the longest. Furthermore, monocrystalline modules tend to be less affected by high temperatures. Though very efficient, the production of monocrystalline is less sustainable, which leads to higher production costs and thus is expensive for the end-user.

POLYCRYSTALLINE

Polycrystalline includes the phrase poly meaning many, which suggests that a polycrystalline panel is made of multiple silicon pieces that are blended. A polycrystalline solar panel is made from melted pieces of silicon formed into wafers with thicknesses varying from 200-400 μm. The production process is relatively cheaper than that of monocrystalline. Polycrystalline modules have lower efficiency compared to monocrystalline panels, as polycrystalline modules have less freedom for the electricity to move because of multiple crystals in each cell. The longevity of a polycrystalline module is greater than 25 years of use. Polycrystalline modules are hot sellers because they provide the best value. They are half the cost of a monocrystalline module while offering efficiency levels up to 15%.

THIN-FILM

Another type of PV solar panel is thin-film. Thin-film modules are manufactured using a variety of materials. Instead of solid silicon wafers, they are composed of non-crystalline silicon placed on top of glass, plastic, or metal. The most commonly used thin-film cells are made of amorphous silicon, but other types of thin-film photovoltaics are entering the market, including copper indium diselenide, cadmium telluride, and gallium arsenide. Manufacturers also place a layer of cadmium telluride between the transparent conducting layer to capture sunlight. Thin Film modules are lightweight, portable, and less expensive, making them optimal for projects with low power requirements. Even though they are the easiest of all types to produce, thin-film panels are still not suitable for residential installations as they require more space. These types of PV panels are used for commercial and industrial projects with the least amount of space restrictions. Thin-film photovoltaic panels have an efficiency of around 7% and up to 18%.

A bifacial solar panel captures sunlight from the front and back of the panel. Such types of PV panels are transparent so that sunlight can go through the panels, reflect off of the ground, and pass through the back of the panel. This allows more electricity to be generated. Monocrystalline solar cells are mostly manufactured with bifacial solar panels. However, some polycrystalline bifacial panels also exist.

Now that we have discussed the different types of PV panels and solar PV systems, let us discuss why PV panels are a better choice for energy. Energy generation through solar panels does not require any raw materials as the sunlight does not deplete. Not only do solar photovoltaic panels are low maintenance, easy to install, and versatile, meaning they can generate electricity anywhere where there is sunlight. With the growth in climate change and increasing awareness about global warming, companies such as Longi and Jinko are working to provide a clean and green energy alternative. Solar panels are a smart choice for a better and cleaner tomorrow.