What is Solar Module? Types of Solar Modules
Every day we keep seeing the Solar Energy usage increasing, and the future also has many good things in this industry that we can avail. There are soo many benefits Solar Modules can address from remote power systems for cabins, remote sensing to many more but do you know what a solar module is?
What is Solar Module?
A single photovoltaic Module/Panel is an assembly of connected solar cells that will absorb sunlight as source of energy to develop electricity.
A group of PV modules (also called PV panels) is wired into an extensive array called PV array to gain a required current and voltage.
When you make up your mind to buy a solar power system, you will encounter three types, and as a layman, it becomes challenging to understand the difference between these technologies. So let’s have a brief understanding of these below:
Mono-crystalline Solar Modules
It is a solar modules comprising mono-crystalline solar cells.
When sunlight falls on the mono-crystalline solar modules, the cells absorb the energy and create an electric field through a complicated process. Hence it comprises of voltage and current which is directly used to run DC.
- The panel cells have a pyramid pattern that offers a larger surface area to collect more energy from the sun’s rays.
- It reduces reflection and thereby increase absorption; the cells are coated with silicon nitride.
- These panels have life span up to 25-30 years.
- They are useful in exhibiting more excellent heat resistance.
- The produced electricity is collected through metal conductors printed into cells.
Polycrystalline Solar Modules
PolyCrystalline solar modules are solar modules that consist of several crystals of silicon in a single PV cell.
Polycrystalline PV panels cover 50% of the global production of modules.
Made of multiple photovoltaic cells and each cell contains silicon crystals that function as a semiconductor device. As the photons from the sunlight fall on the PN junction, it imparts energy to the electrons to flow as electric current.
- Polycrystalline silicon is the most consolidated and tested photovoltaic technology.
- The conversion efficiency in diffused light conditions (e.g. on a cloudy day) is better than in monocrystalline modules.
- Poly-crystalline cells are slightly cheaper than monocrystalline ones.
- Poly-crystalline is having 25 years of life span.
Thin-film Solar Modules
If there’s one product that has the opportunity to benefit from the tariffs on crystalline silicon solar modules, it’s the thin-film module.
It is a good option for projects with lesser power requirements but needs for lightweight and portability. Thin-film technologies have produced a maximum efficiency of 20.3%, with the most common material amorphous silicon at 12.5%.
- Thin-film panels have 30% less than crystalline panels due to the module itself and its installation process.
- It is easy to handle.
- flexible compared to conventional solar technology.
- You can get ut quickly in thin wafer sheets.
Solar PV Efficiency
Solar modules are between 15% and 20% efficient, with outliers on either side of the range. High-quality solar modules can exceed 22% efficiency, but the majority of photovoltaic panels available are not above 20% efficiency.
On average, today have efficiency ratings as high as 22.8%, whereas the majority of modules range from 16% to 18% efficiency rating. SolarSmiths solar modules are known for being the most efficient solar module brand available on the market. Our experts always strive hard to be there with you with your plan for the solar module, so connect today and help you with maximum efficiency projects.
Solar Photovoltaic System: Types, Components, and Advantages Disadvantages
The solar photovoltaic system or solar PV system is a technology developed to transform the energy from the sun’s rays into electricity through solar panels.
This technology is eco-friendly, safe to use, and generates green energy without causing pollution. A photovoltaic system comes in various sizes and is useful in solar water heating, ventilation, lighting, and transportation.
The first photovoltaic cell was discovered in 1954 by Gerald Pearson, Daryl Chaplin, and Calvin Souther Fuller. Since then, it has been an adequate replacement and a solution to the depletion of fossil fuels. Today, it has become a vital source of energy for recharging devices.
Types Of Solar PV Systems
There are three common types of solar PV systems: grid-connected, hybrid, and off-grid.
These PV solar panels supply electricity to customers by converting the sun’s energy into solar energy using different techniques.
- Grid-connected solar photovoltaic systems: Also known as the utility-interactive PV system, this photovoltaic module uses a basic grid-tied inverter. It does not require a battery to operate and has essential components. It transforms PV solar energy into AC power through the inverter. It is a practical solar PV module that reduces the overall electricity consumption.
- Hybrid solar photovoltaic systems: These PV modules are a modified version of a grid-tied system and consist of a battery backup. It is integrated with diesel generators and converts energy to AC or DC voltage.
- Off-grid solar photovoltaic systems: It is an ideal device for people who cannot use grid-connected solar photovoltaic systems due to geographical restrictions or high costs.
It is known as a stand-alone PV system due to its efficiency in standing independently of the power grid. The battery stores the PV solar energy for later use.
Different Components Of Solar PV System
Every solar photovoltaic system has six parts:
- A charge controller
- The solar PV array
- A battery bank
- A utility metre
- An inverter
- An electric grid
Although the battery bank and charge controller are optional components, they help to store additional solar energy for use at night or during the rainy season.
The role of each element of the solar photovoltaic panels is as follows:
- The PV array aids in converting solar energy into DC.
- The charge controller keeps the battery safe from overcharging as overcharging can cause an explosion.
- The battery bank stores extra energy from the sun for future or emergency use.
- The inverter transforms the DC power into AC electricity. This is essential in supplying the required energy to the household appliances.
- The power metre determines the current required for household purposes and the amount that is sent back to DC.
- At night, the electricity is sent via the electricity grid.
Advantages of Solar Photovoltaic System
Since the PV system evolved, it has helped people in many ways. Its eco-friendly utility has been quite beneficial in saving the environment from the side effects of using fossil fuels.
The following are some advantages of the solar photovoltaic system:
- Solar energy is a renewable energy source. While fossil fuel can be exhausted, solar energy never exhausts. Since the power is drawn from the sun, it will never deplete.
- It is easy to access from any location due to its availability.
- It is an economical energy source as one does not need to purchase energy from sunlight. Although a solar photovoltaic system is required to draw the power from the sun, the sun being the raw material is free and abundant.
- It is ideal for distributed power generation and intelligent energy networks.
- The maintenance cost is relatively low compared to the other sources of energy.
- It provides noiseless operation and, thus, does not contribute to noise pollution.
Disadvantages Of The Solar Photovoltaic System
A Solar PV panel system also has some drawbacks, such as:
- It has intermittency problems. In other terms, it does not charge during the nighttime due to the unavailability of solar power.
- It requires an extra equipment inverter to convert the sunlight into usable electricity.
- It requires an open area to install the photovoltaic solar panels and needs ample space to accommodate them.
- Although the solar energy photovoltaic module requires minimal maintenance, if this particular need is overlooked, the module will likely be damaged after some years of operation.
Conclusion
The photovoltaic solar system has both pros and cons, yet the advantages are numerous. Solar energy is essential. It delivers benefits on a micro scale for house and company owners, society, and the environment.
Photovoltaic panels are widely used for charging home appliances today and have become an efficient source of energy supply.
FAQs
Is it possible to use solar energy throughout the day?
Yes, it is possible to use solar energy for 24 hours. Crescent Dunes in Nevada is the first solar power plant that operates throughout the day.
Do solar power function during the night?
Yes, PV solar power functions during the night. The battery bank stores the excess energy in the power grid, and solar power utilises it in the dark.
Is UV light required for solar panel photovoltaic operation?
Solar PV panels mainly transform visible light into electricity but may also utilise about half of thermal light. But PV solar panels require less amount of UV light for the process.
Types of PV Modules: Part A
Photovoltaic (PV) cells also known as solar cell, is an optoelectronic device which converts solar energy into electric energy. These PV cells are connected in series or parallel to generate required current, voltage and power. The resulting structure is known as PV module. The modules contain 60, 72, 96 cells according to the manufacturer. The PV modules are the key components of a PV system. Two or more PV modules connected in series is known as a string of modules. PV array is an arrangement of many PV strings connected in parallel to generate required energy.
Majority of PV cells are made up of a semiconductor material called silicon. It is known for its abundance and is the most common semiconductor material. The crystalline structure of silicon helps in better efficiency of a solar cell. Approximately, 95% of the solar modules are made of this material. Solar cells made of silicon are known for longevity, high efficiency and low cost. Modules last for more than 25 years, actually delivering over 80% of their initial power. Silicon can be used in its polycrystalline form or single crystal form to make the solar cells.
CLASSIFICATION OF MODULES
Though there are many other factors on which the modules might be classified, in general they are classified into 4 types.
MONOCRYSTALLINE MODULES
The “mono” in the name represents single crystal. These modules are made from single silicon crystal of high purity.
The solar cell of a monocrystalline solar module, is formed by creating a cylindrical shape of the silicon which is referred to as silicon ingot. They are further sliced into squares with sloping edges, known as silicon wafers. These silicon wafers act as solar cells, and are arranged in rows and columns to create a module.
The manufacturing process is slow, intense, complex and expensive. It also involves a lot of energy to crystallize the silicon and also wastage of silicon crystals during slicing to make wafers. Hence, they are expensive than the other modules.
Monocrystalline modules are distinguished by their uniform black colour and round edges. The efficiency of monocrystalline cells is around 18%. 25%.
The standard size of a monocrystalline solar panel is:
60 cell solar panel : 39-inch X 66 inch (3.25 ft X 5.5 ft).
72 cell solar panel: 39-inch X 77 inch (3.25 ft X 6.42 ft).
The standard weight of a monocrystalline solar panel is:
60 cell solar panel: 16. 22 kg.
72 cell solar panel: 22. 28 kg.
The monocrystalline modules are highly efficient, occupy less space and their power output is less affected by high temperatures. They tend to have more lifetime (25 years) compared to other types of modules.
Expensive. The complexity of the manufacturing process increases the cost for end user.
POLYCRYSTALLINE MODULES
The “poly” in the name represents many/multi crystal structure. The polycrystalline modules are made by melting silicon powder and recrystallizing the silicon to grow large grains in a mould and then cutting square blocks from which the wafers are sliced.
The manufacturing process is less complex, less energy intensive requires less manpower and is cheaper compared to monocrystalline. They are faster in production compared to monocrystalline.
Polycrystalline modules are distinguished by their blue colour with the different grains visible on closer inspection and squared edges.
The efficiency of polycrystalline cells power is around 15-19%.
The standard size of a polycrystalline solar panel is:
60 cell solar panel: 39-inch X 66 inch (3.25 ft X 5.5 ft).
72 cell solar panel: 39-inch X 77 inch (3.25 ft X 6.42 ft).
The standard weight of a polycrystalline solar panel is:
60 cell solar panel is 16. 22 kg.
72 cell solar panel is 22. 28 kg.
They are the cheapest among crystalline solar modules in today’s market. If you are going for a cost-efficient system then you should definitely consider polycrystalline.
Their manufacturing process involves less silicon waste.
It is not aesthetically pleasing.
Less space efficient, low silicon purity and less efficient compared to monocrystalline.
The power output will decrease with increase in temperature and they are not as efficient as monocrystalline at high temperatures.
PERC MODULES
PERC is the abbreviation of Passivated Emitter and Rear Cell. They have a improved solar cell architecture are the advancement of monocrystalline solar modules. They provide up to 2. 3% more efficiency than the monocrystalline modules and improved power output at higher temperatures and during sunrise and sunset times. This enhancement in efficiency is achieved by adding a passivation layer on the rear surface to reduce the recombination of the charge carriers.
It also improves the reflectivity of the light back into the cell, increasing the amount of solar radiation that gets absorbed. It allows greater wavelengths of light to be reflected. Light waves of higher frequencies can’t be absorbed by silicon wafers. So they pass through, heating the cell’s metal back sheet and reducing its efficiency. The passivation layer prevents the back sheet from heating by reflecting these higher wavelengths.
Their manufacturing cost is a little bit high compared to the monocrystalline modules due to added materials and process steps but they can end up having a lower average cost per kWh energy generated due to their higher efficiency and improved generation.
THIN-FILM MODULES
Thin film modules are produced by applying a thin layer of semiconducting material (photovoltaic material) on different durable substances like glass, plastic or metal. Compared to the crystalline modules, thin-film are durable, simpler, lighter. However, the efficiency of these modules is much lower compared to the crystalline modules.
Further, there are different variants in thin-film. The different materials used in thin-film technology are:
Copper indium gallium selenide (CIGS)
Thin-film modules are distinguished by their uniform black colour. Their efficiency is 2-3% less than the crystalline modules. Minimum thickness for CdTe is around 4–6μm, for CIGS it is around 3–4μm.
They have low manufacturing cost. They are more efficient for industrial purposes. They are aesthetic and can also be made into flexible panels. High temperatures or shading have very lower effect on the power output as compared to crystalline modules.
They are not space efficient. You require large area to install them which makes then unsuitable for residential areas. The degradation is much more process dependent and can be higher as compared to the crystalline modules.
SUMMARY
Below shown are the comparison of three module technologies.
A closer view of mono and poly solar cells.
Author: Jyoshna, Jr. Engineer
Disclaimer: No rights claimed over any of the images used in the blog. All rights reserved to the respective copyright owners.
Types of Solar Panels: Pros and Cons
Emily Rhode is a science writer, communicator, and educator with over 20 years of experience working with students, scientists, and government experts to help make science more accessible and engaging. She holds a B.S. in Environmental Science and an M.Ed. in Secondary Science Education.
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There are three main types of solar panels commercially available: monocrystalline solar panels, polycrystalline solar panels, and thin-film solar panels. There are also several other promising technologies currently in development, including bifacial panels, organic solar cells, concentrator photovoltaics, and even nano-scale innovations like quantum dots.
Each of the different types of solar panels has a unique set of advantages and disadvantages that consumers should consider when choosing a solar panel system.
Monocrystalline solar cells are slower and more expensive to produce than other types of solar cells due to the precise way the silicon ingots must be made. In order to grow a uniform crystal, the temperature of the materials must be kept very high. As a result, a large amount of energy must be used because of the loss of heat from the silicon seed that occurs throughout the manufacturing process. Up to 50% of the material can be wasted during the cutting process, resulting in higher production costs for the manufacturer.
But these types of solar cells maintain their popularity for a number of reasons. First, they have a higher efficiency than any other type of solar cell because they are made of a single crystal, which allows electrons to flow more easily through the cell. Because they are so efficient, they can be smaller than other solar panel systems and still generate the same amount of electricity. They also have the longest life span of any type of solar panel on the market today.
One of the biggest downsides to monocrystalline solar panels is the cost (due to the production process). In addition, they are not as efficient as other types of solar panels in situations where the light does not hit them directly. And if they get covered in dirt, snow, or leaves, or if they are operating in very high temperatures, their efficiency declines even more. While monocrystalline solar panels remain popular, the low cost and rising efficiency of other types of panels are becoming increasingly appealing to consumers.
Polycrystalline Solar Panels
As the name implies, polycrystalline solar panels are made of cells formed from multiple, non-aligned silicon crystals. These first-generation solar cells are produced by melting solar grade silicon and casting it into a mold and allowing it to solidify. The molded silicon is then sliced into wafers to be used in a solar panel.
Polycrystalline solar cells are less expensive to produce than monocrystalline cells because they do not require the time and energy needed to create and cut a single crystal. And while the boundaries created by the grains of the silicon crystals result in barriers for efficient electron flow, they are actually more efficient in low-light conditions than monocrystalline cells and can maintain output when not directly angled at the sun. They end up having about the same overall energy output because of this ability to maintain electricity production in adverse conditions.
The cells of a polycrystalline solar panel are larger than their monocrystalline counterparts, so the panels may take up more space to produce the same amount of electricity. They are also not as durable or long-lasting as other types of panels, although the differences in longevity are small.
Thin-Film Solar Panels
The high cost of producing solar-grade silicon led to the creation of several types of second- and third-generation solar cells known as thin-film semiconductors. Thin-film solar cells need a lower volume of materials, often using a layer of silicon as little as one micron thick, which is about 1/300th of the width of mono- and polycrystalline solar cells. The silicon is also of lower quality than the kind used in monocrystalline wafers.
Many solar cells are made from non-crystalline amorphous silicon. Because amorphous silicon does not have the semiconductive properties of crystalline silicon, it must be combined with hydrogen in order to conduct electricity. Amorphous silicon solar cells are the most common type of thin-film cell, and they are often found in electronics like calculators and watches.
Other commercially viable thin-film semiconductor materials include cadmium telluride (CdTe), copper indium gallium diselenide (CIGS), and gallium arsenide (GaAs). A layer of semiconductor material is deposited on an inexpensive substrate like glass, metal, or plastic, making it cheaper and more adaptable than other solar cells. The absorption rates of the semiconductor materials are high, which is one of the reasons they use less material than other cells.
Production of thin-film cells is much simpler and faster than first-generation solar cells, and there are a variety of techniques that can be used to make them, depending on the capabilities of the manufacturer. Thin-film solar cells like CIGS can be deposited on plastic, which significantly reduces its weight and increases its flexibility. CdTe holds the distinction of being the only thin film that has lower costs, higher payback time, lower carbon footprint, and lower water use over its lifetime than all other solar technologies.
However, the downsides of thin-film solar cells in their current form are numerous. The cadmium in CdTe cells is highly toxic if inhaled or ingested, and can leach into the ground or water supply if not properly handled during disposal. This could be avoided if the panels are recycled, but the technology is currently not as widely available as it needs to be. The use of rare metals like those found in CIGS, CdTe, and GaAs can also be an expensive and potentially limiting factor in producing large amounts of thin-film solar cells.
Other Types
The variety of solar panels is much greater than what is currently on the commercial market. Many newer types of solar technology are in development, and older types are being studied for possible increases in efficiency and decreases in cost. Several of these emerging technologies are in the pilot phase of testing, while others remain proven only in laboratory settings. Here are some of the other types of solar panels that have been developed.
Bifacial Solar Panels
Traditional solar panels only have solar cells on one side of the panel. Bifacial solar panels have solar cells built on both sides in order to allow them to collect not only incoming sunlight, but also albedo, or reflected light off the ground beneath them. They also move with the sun in order to maximize the amount of time that sunlight can be collected on either side of the panel. A study from the National Renewable Energy Laboratory showed a 9% increase in efficiency over single-sided panels.
Concentrator Photovoltaic Technology
Concentrator photovoltaic technology (CPV) uses optical equipment and techniques such as curved mirrors to concentrate solar energy in a cost-efficient way. Because these panels concentrate sunlight, they do not need as many solar cells to produce an equal amount of electricity. This means that these solar panels can use higher quality solar cells at a lower overall cost.
Organic Photovoltaics
Organic photovoltaic cells use small organic molecules or layers of organic polymers to conduct electricity. These cells are lightweight, flexible, and have a lower overall cost and environmental impact than many other types of solar cells.
Perovskite Cells
The Perovskite crystalline structure of the light-collecting material gives these cells their name. They are low cost, easy to manufacture, and have a high absorbance. They are currently too unstable for large-scale use.
Dye-Sensitized Solar Cells (DSSC)
These five-layered thin-film cells use a special sensitizing dye to help the flow of electrons which creates the current to produce electricity. DSSC have the advantage of working in low light conditions and increasing efficiency as temperatures rise, but some of the chemicals they contain will freeze at low temperatures, which makes the unit inoperable in such situations.
Quantum Dots
This technology has only been tested in laboratories, but it has shown several positive attributes. Quantum dot cells are made from different metals and work on the nano-scale, so their power production-to-weight ratio is very good. Unfortunately, they can also be highly toxic to people and the environment if not handled and disposed of properly.
Almost all solar panels sold commercially are monocrystalline, common because they’re so compact, efficient, and long-lasting. Monocrystalline solar panels are also proven to be more durable under high temperatures.
Monocrystalline solar panels are the most efficient, with ratings ranging from 17% to 25%. In general, the more aligned the silicon molecules of a solar panel are, the better the panel will be at converting solar energy. The monocrystalline variety has the most aligned molecules because it’s cut from a single source of silicon.
Thin-film solar panels tend to be the cheapest of the three commercially available options. This is because they’re easier to manufacture and require less materials. However, they also tend to be the least efficient.
Some may choose to buy polycrystalline solar panels because they’re cheaper than monocrystalline panels and less wasteful. They’re less efficient and bigger than their more common counterparts, but you might get more bang for your buck if you have abundant space and access to sunshine.
Thin-film solar panels are lightweight and flexible, so they can better adapt to unconventional building situations. They’re also much cheaper than other types of solar panels and less wasteful because they use less silicon.
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