After completing the survey of the solar power system installation area , we have clearly outlined the main parameters:
- Electrical capacity needed to generate.
- Calculate the appropriate location.
- Overview of system installation costs .
To proceed, you need to review the available technologies and products so you can choose the right product for your requirements and applications.
Your choice of components and system design depends on whether the solar power model is a stand-alone system , including backup systems and grid supplementation, or a grid-connected system .
Because there is a difference in design between independent systems and grid-connected systems , this content will be presented in detail by VREnergy in the article Comparison of independent & grid-connected solar power systems . The core of every solar energy system is the solar panel. Most solar panels can be used in both stand-alone and grid-connected systems, although some manufacturers now market specially designed, high-voltage solar panels. specifically for grid-connected systems, but the selection criteria remain largely unchanged.
So what will the main parts in the Solar Power System include? Please read this article in detail!
There are currently three technologies used to manufacture solar panels. Each technology has its own advantages and disadvantages.
Your solar power system is residential, so this section will not cover expensive solar panels used on satellites and in advanced research laboratories, focusing only on solar panels. Photovoltaics are popular and reasonably priced.
Amorphous solar panel
The cheapest solar technology today is amorphous solar panels, also known as thin-film solar panels .
Unlike other solar panel technologies, amorphous panels perform very well even when partially shaded. While it is best to eliminate shading whenever and wherever possible, amorphous panels can continue to operate at sufficiently high efficiency even when part of the panel array is shaded.
Amorphous panels can also be manufactured and installed on curved surfaces. They can be made durable enough for people to walk on them after installation. Some companies have begun making amorphous solar panel tiles so that new homes can incorporate solar panel systems on the roof.
This combination creates the possibility of integrating amorphous panels into power consuming products, such as mobile phones, laptop computers, or mobile products such as caravan roofs, expanding the range of applications. and create more options for consumers.
Amorphous panels are the type with the lowest production cost, currently manufactured using low-cost screen-printed amorphous thin film technology. In the past few years, the price of this type of panel has decreased annually by about 30%, and is expected that by 2015 it will be perhaps only 50% compared to the price in 2012.
Due to low efficiency, amorphous solar panels have an area twice as large as crystalline panels of the same capacity, so amorphous panels can only be used where area is not limited or only requires high power. low power output.
In terms of environmental impact, the amorphous panel manufacturing process has a much lower carbon footprint than other panel technologies.
Most amorphous solar panels have low wattage. They can only work well in electrical systems with a capacity of no more than 300W; Not suitable for larger capacities, due to the need for many panels, increased installation costs, electrical wiring costs… gradually becoming economically ineffective.
Therefore, amorphous solar panels are suitable for portable or portable household electrical products, used as a power source integrated into the product, or for relatively large systems, where the panels are integrated into the roof structure on newly built houses.
Polycrystalline solar panel
Polycrystalline solar panels are made from many solar cells, each consisting of Si crystal layers. Under direct sunlight, they have a higher efficiency than amorphous solar panels, with an efficiency level of about 13-18%.
As a result, polycrystalline solar panels are only about one-third the size of amorphous panels of the same power, thus taking up less space and being easier to install.
Polycrystalline solar panels have a useful life of about 25 years. Solar panels came into commercial use in the late 1970s and early 1980s, but many have remained in good working order ever since.
The process of manufacturing polycrystalline panels is relatively complicated, so it is a bit expensive, the price is about 20-30% higher than amorphous panels. The environmental impact, the amount of carbon emitted from the manufacturing process, is also higher than that of amorphous panels.
The cost of polycrystalline panels is falling, thanks to increased production scale and an increase in the number of television sets with large screens, using the same specialized standard glass. Over the past five years, the price of this type of panel has decreased annually by about 25%, and will continue to decrease in the near future.
Monocrystalline solar panel
Monocrystalline solar panels consist of many small photovoltaic cells, each cell is a thin layer of Si crystals. This type of solar panel has the highest efficiency today, about 15-24%.
Monocrystalline solar panels have similar properties to polycrystalline panels. Due to their high efficiency, they are the smallest panel size (in terms of watts) available today.
Monocrystalline panels have the highest production costs, therefore the most expensive prices, about 35-50% higher than polycrystalline panels of the same capacity.
Choose solar panel technology
For most applications, polycrystalline panels are the best solution, with a reasonable price and relatively compact size.
Amorphous panels can be a good choice for small capacity systems where space is large; but are not suitable for power requirements higher than a few hundred watts due to their general size, unless you have a large enough space for these panels.
Select solar panel
Not all solar panels are of the same quality. Types from famous companies may be a bit expensive, but quality is guaranteed. Cheap, unbranded solar panels often have a short lifespan and performance drops sharply on cloudy days.
Choose quality solar panels
If your investment in a solar power system will last for many years, you should choose to buy solar panels from one of the companies Kyocera, Panasonic, Clear Skies, Hyundai, Sanyo, Mitsubishi, Solar Frontier, or Sharp. Currently, the popular polycrystalline solar panel is from Kyocera company, and the amorphous type from Mitsubishi and Solar Frontier companies is considered to have good quality and affordable price.
Buy cheap solar panels
Not every solar system needs to operate well for 20 years. If you need a small, inexpensive system to power a caravan or recreational vehicle, or your requirements are not too high, such as powering lights in a warehouse, buy a cheap solar panel. is probably the economical and reasonable choice.
Over the years, the quality of inexpensive solar panels has been continuously improved. 6-7 years ago, buying cheap, unbranded products made in China was considered a “waste of money” solution. Many panels are assembled incorrectly, allowing water to flow through the frame channels and damage the solar cells. Most use thin, poor quality glass that fades over time and is easily chipped, cracked or broken. The solar cells in this type of panel often do not meet standards and degrade quickly.
Today, most of those problems are being solved or improved, and if you buy cheap solar panels on eBay, you will have a quality product that can operate reliably for 5-10 years, even longer. If you buy a solar panel from a manufacturer you have never heard of, you should keep the following in mind:
Buy panel arrays with larger capacity than needed
If you buy cheap panels, you can save up to 50% of the cost compared to branded products. However, this type will degrade faster and have lower performance than famous products.
To solve this problem, buy solar panels with a higher power rating (usually expressed as peak power Wh) of about 15% of the actual demand, or buy additional solar panels if you order them. by panel array. Even if you buy more, you will still save costs and have spare capacity.
With cheap solar panels, you won’t get a 5, 10, 15, or 20 year warranty, but usually just one or two years. Please check the warranty terms carefully.
Please see the warranty terms that guarantee minimum power output under controlled conditions. The industry standard is to guarantee no less than 80% of rated capacity under controlled conditions.
If you have a warranty claim, check to see how you can make a warranty claim. In general, unbranded companies often avoid warranty responsibilities, buying a new one is sometimes better than waiting for a warranty.
Energy storage (Acquy)
Energy storage in a solar power system plays an important role in providing a continuous and stable power source, especially in situations when there is no sunlight such as at night or in cloudy conditions. . Energy storage typically consists of a group of electrochemical cells (batteries) connected together to form an energy storage system.
How it works
When sunlight shines on the solar panel and generates DC electricity, part of this electricity is used to provide power to the devices in the system and is also used to charge the energy storage unit. .
During sunlight, the inverter system will convert DC electricity from solar panels into AC electricity suitable for home or business use. This AC power is used to power electrical devices, and any excess power remaining after supplying these devices is fed into the energy storage charging process.
When there is no sunlight, for example at night or in cloudy conditions when solar power output is reduced, energy storage becomes the main source of power for electrical equipment. The energy stored in the storage unit from sunlight days will be released and converted into AC electricity through the power converter to provide continuous power.
- Energy storage helps ensure a continuous and stable power supply in situations where there is no sunlight.
- Energy storage systems can help reduce dependence on power supplies from the public grid and reduce monthly electricity costs.
- Energy storage has the ability to store excess solar energy for later use, helping to optimize the use of renewable energy.
Solar power inverter (Inverter)
The inverter is an important component in the solar power system, responsible for converting electricity from DC (direct current) to AC (alternating current). Solar power generated from solar panels is DC, but most household and industrial electrical equipment used works with AC power. Therefore, inverters are important converters to ensure that the electricity from the panels can be used effectively in these devices.
How it works
When the solar panel generates DC electricity, it sends this DC current into the inverter. Inside the inverter, there are special electronic circuits and components designed to perform the conversion process from DC to AC electricity. This process includes the following steps:
Convert DC to AC: First, DC power from the battery panel is fed into the inverter. In this part, the inverter will use components such as a pulse width modulation (PWM) inverter to create a voltage and current signal in the form of a square wave wave. This square pulse wave is quite similar to the waveform of AC electricity.
Frequency and voltage adjustment: The next step is to adjust the frequency and voltage of the generated square wave to create an AC electrical signal that is accurate in frequency and voltage. The frequency and voltage of this signal must usually comply with the AC electrical standard used in the electrical system.
Filtering and quality control: Once an AC electrical signal has been generated, the inverter uses filtering and control circuits to smooth and adjust the quality of this signal. This helps ensure that the AC electrical signal meets quality requirements and does not cause network disturbances.
Introducing into the power grid or using directly: For solar power systems linked to the public power grid, the AC electrical signal, after being transformed and adjusted for quality, will be fed into the power grid through the connection system. connect. If the solar power system is operating independently (self-sufficient), then the AC electrical signal will be used directly to provide power to the devices.
- Inverters help optimize power use from solar panels, converting DC power to AC power for use in home and industrial electrical equipment.
- The inverter also has the ability to monitor and adjust system performance, including monitoring panel performance and automatically adjusting power output.
Solar battery mounting bracket
You can make your own solar panel mounting bracket or buy a pre-fabricated system in modules.
When designing the mounting system, you must consider the force or load of the rack, making it durable enough to not be damaged by strong winds. If installing a solar system in a hot climate, there should be good ventilation behind the panels to reduce heat buildup.
The support structure must be able to optimally adjust the tilt angle of the panel array towards the sun.
If you have never installed a solar system, you should probably purchase a mounting structure from a solar panel supplier. If you have experience, you can make your own rack structure depending on your preferences.
Electrical wire connecting Panel array
The wiring connects the solar panels together and connects the solar panel array to the controller.
These power cables are considered to “connect” the panel array. You can buy them in specialized lengths, or make your own as required. These cables conduct high currents, are resistant to high temperatures, and ultraviolet rays. They must have sufficiently thick and flexible insulation to avoid the risk of damage by animals.
If you plan to wire the panel array in parallel instead of in series, you need to make sure the wires can withstand the high current generated in the panel array. If you are designing a parallel system, the following section presents a method for calculating the electrical cable sizes needed for the components in the independent electrical system.
Fuses and Circuit Breakers (Isolation Switches)
The ability to isolate parts of an electrical system is important, especially during system installation and maintenance activities. Even relatively low voltages can cause accidents.
Small capacity systems should also have fuses between the batteries and the controller and/or inverter. If any problem occurs in the system, replacing a fuse is always cheaper than repairing or replacing a burned out battery or controller.
Even in the smallest system, you need to have isolating switches (breakers) in the design. This allows the battery bank to be de-energized when maintenance is required. For systems with multiple solar panels, and any system connected to the grid, a circuit breaker or isolation switch should be installed to disconnect the solar panel array. You should install circuit breakers for all panel arrays with a rated capacity of 100 W or more.
If your solar panels, for some reason, have to be located slightly away from the inverter or controller, you should have one circuit breaker installed near the solar panels, and one close to the inverter or controller. control. You can easily disconnect panels from the system for maintenance or when problems occur.
It is necessary to choose a circuit breaker or isolating switch that can work well with high-current DC circuits, with contacts that do not arc or spark. Solar power system suppliers often have this type of switch available.
If you plan to install a solar power system connected to the grid, you need to use circuit breakers and isolating switches, capable of operating with AC power, to disconnect the inverter from the grid. You should install one isolation switch near the inverter, and a second switch at the power distribution panel.
Protects against cold contact
Ground fault protection will ensure that if a short circuit occurs in the solar panel array, the current will be cut off almost instantaneously. This will prevent the risk of a malfunction in the controller or panel array, thereby reducing the risk of electric shock.
Ground fault protection works by measuring the current entering and exiting the circuit. If everything is working properly, the input current will equal the output current. However, if there is an electrical “leak” or a partial short circuit, the system will easily detect the difference in current intensity and immediately disconnect the circuit. A partial short circuit can occur if a solar panel is broken, broken, or a person or animal touches the bare wire.
Most solar inverters and controllers have ground fault protection, using a built-in residual current device (RCD) , which in the United States and Canada is called a ground fault circuit interrupter (GFI) . Many experts recommend installing a separate ground fault protector, even if the controller or inverter has built-in ground fault protection. Since the price of RCD or GFI is relatively cheap, and has the potential to increase protection, you should follow the recommendations of experts.
You should have separate fault protection for DC and AC circuits:
- For all solar panel systems with a capacity above 100 W; and every system installed in the house, you should have ground fault protection between the solar panels and the controller or inverter.
- If you install a DC power source in your home to operate equipment, you must install a ground fault protector between the controller and the DC source.
- If you use an inverter, you should install a ground fault protector between the inverter and any load.
There are specialized RCD (or GFI) kits for DC circuits available from solar panel suppliers.
VREnergy – Professional solar power EPC general contractor
VREnergy sounds like a unit specializing in solar power projects under the EPC (Engineering, Procurement, Construction) general contractor model , meaning they are responsible from the design stage, equipment procurement to construction. Construction and implementation of solar power projects.
Consulting on quality products and equipment
VREnergy has a consulting role to help customers choose the most suitable products and equipment for their solar power projects. This helps ensure system performance and durability.
Team of experts
VREnergy owns a team of skilled experts, including people with knowledge and experience in the field of solar power. This ensures that the project is carried out by highly qualified people.
VREnergy uses modern equipment to carry out the project. This can ensure that the build and deployment process will be carried out with efficiency and high quality.
Warranty and after-sales service
This point demonstrates VREnergy’s commitment to quality and customer satisfaction. Dedicated warranty and after-sales service helps customers feel secure about maintaining and repairing the system after project completion.
We are very honored to accompany and contribute to enhancing the value of your business. With pride in bringing superior solutions along with outstanding products, reasonable prices and considerate maintenance. That is what we enjoy when accompanying our customers.