Grid Tied Solar System Components

Planning to get a solar system and an on-grid solar panel system. Sounds great, and I guess you have gathered all the necessary information about it. Information like types of grid tied solar system components required and working. Have you compared its advantages and disadvantages? No? If that is the case, then here is the solution. This article is dedicated to on-grid solar system components along with their advantages, working, and disadvantages. Also, with grid tied solar system cost mentioned herein, you can get a rough idea of how much expense to expect.

What is Grid Tied Solar System?

A solar panel system that is connected to the electricity grid is known as a grid-tied or on-grid solar system. This system does not usually come with a battery backup. But they can be backed by batteries in which excess power generated by the panels is stored. This stored power is transferred to the large utility grid. In a grid-tied solar system, power from the utility grid is imported in case of a shortage of power supply from the panels.

What are Grid Tied Solar System Components?

You already know what is grid tied solar system, but what it is without its components. Thus, here is a list of all the required components of a grid-tied solar system.

1. Cable and Wiring

To transfer generated power from solar panels to the inverter and then to the utility grid, proper wiring required. Conducting material and insulation are two factors differentiating wire types. Here is a list of factors to be considered for wires for usage in solar power systems.

a) Aluminum or Copper

These two are the most common conducting materials used in solar power installation in residential and commercial applications. Copper, having more conductivity than aluminum, carries more current than aluminum. Also, aluminum wires are susceptible to bending but are less expensive than copper wires. These wires are not permitted for indoor residential applications.

b) Solid or Stranded

Many small wires make up stranded wire, giving it more flexibility, and are recommended for large-size applications. Stranded wires have better conductivity.

c) Insulation

Cables are protected from heat, moisture, chemicals, or ultraviolet with an insulation covering.

I) PV (photovoltaic) wire, USE-2 (Branch Circuit Cable-Single Conductor), and RHW 2 (Moisture resistant thermoplastic) have UV and moisture-resistant outer covering thus, can be used in wet conditions and outdoors. Make sure they are sunlight resistant.

II) THHN (Thermoplastic High Heat-resistant Nylon-coated wire) is commonly used in indoor and dry locations.

III) THW (Thermoplastic Heat Water-resistant), THWN (Thermoplastic Heat Water-resistant Nylon Coating), and TW (Thermoplastic Water-resistant) can be used both indoors and outdoors in conduit.

IV) UF (Underground Feeder) and USE (Branch Circuit Cable-Single Conductor) are considered good for underground applications or at places with moisture.

V) Temperature ratings of different types of wire

• PV – 90° Celsius (194°F) wet and 150° C (302° F) dry
• THHN – 90° C (194°F)
• THW – 75° C to 90° C (167°F 194°F)
• THWN – 75° C wet (167° F) and 90° C (194° F dry)
• TW – 40° C (140°F)
• UF & USE – 60° C to 75° C (140°F 167°F)
• USE-2 & RHW-2 – 90° C (194°F)

d) Color

Electricity wire insulation is color-coded to define its functioning and use. One with a better understanding of coding can easily troubleshoot and repair them. Wires, one of the essential grids tied solar system components, have different labels depending on AC and DC current. Here is a table for color coding in different current types.

Alternating Current		Direct Current
Color	Application	Color	Application
Black/red/other colors except the ones mentioned below	Ungrounded and hot	Red	Positive
Green or bare	Equipment ground	Green or bare	Equipment ground
White	Grounded conductor	White	The negative or grounded conductor

2. Combiner Box

This component brings the output from several solar strings together. Each string conductor is connected to a fuse terminal. The output of fused inputs is then combined onto a single conductor connecting the combiner box to the inverter. A solar combiner box also consolidates incoming power into one main feed that further distributes it to a solar inverter. Both overcurrent and overvoltage protection is provided to the inverter further enhancing its reliability and protection.

To limit power loss, optimal positioning of the combiner box between the solar inverter and solar modules is necessary. Also, they are low maintenance, but their quality is a main characteristic of their performance.

Also Read: Solar Module Vs Solar Panel: What’s the Difference?

3. Grid Tie Inverters

Specifically used for solar PV modules, a grid-tied inverter is a device that converts direct current (DC) coming from solar modules to alternating current (AC). This converter power is then supplied to the grid to be further used in running devices and appliances. Grid-tied inverters are connected between the power grid and the panels.

The phase and voltage of the sine wave alternating current waveform of the power grid must be accurately matched with the accuracy of a grid-tied inverter. These inverters can switch the power supply from panels to the grid at night and back to the grid. A solar grid-tied inverter is necessary because it synchronizes frequency and output voltage to its connected grid.

4. Net Meter (Power Meter)

This device is the basic necessity in the list of grid-tied solar system components. It calculates the input and output of power to and from the utility grid. It is similar to electric meters already installed at houses, but net meters measure the import and export of power. Whereas electric meters are just for measuring the unit of electricity supplied and used from the grid. Excess power generated by solar panels is fed into the grid, which converts into credit for you. This credit is put to use for drawing electricity from the grid at night or on low-production days. You will not be charged for the units until the amount of power is fed into the meter.

Also See: What is Annual Solar Savings?

5. Racks and Mounts

To hold solar panels in one place, racks and mounts are required. After all, you cannot just leave your solar panels on a bare roof. It is necessary to place them on racks or mounts as this enables proper ventilation and inclination of panels. Sun changes its position throughout the day and flat-lying solar panels cannot get enough sunlight during different hours of the day. Inclination or orientation of panels with mounts and racking enables setting them up at a certain angle for maximum sunlight exposure.

Note: The inclination and angle of panels are decided as per your roof type and your location.

6. Safety Switches

A breaker panel is required in grid-tied solar systems, and it is similar to the one you have at home, but with more additional breakers for inverters. Some safety switches cut off connections between solar panels and inverters to avoid damage to inverters. Installing AC & DC disconnects properly ensures overall safety.

• DC disconnects, also referred to as PV disconnects, are placed between inverter and solar panels and in some cases, inverters have inbuilt DC connects.
• AC disconnects are installed between the inverter and the grid. Mostly mounted on the exterior wall near the electric meter. In case of overvoltage or so, it breaks current flow from the inverter to the grid. Safety devices are essential among grid tied solar system components.
• Variables to consider when determining the size of disconnects for PV systems are circuit load, voltage, wiring, circuit load, and amps/breaker size.

7. Solar Panels

These are the main components of any solar panel system. There are 3 types of solar panel system available in the market, namely monocrystalline, polycrystalline, and thin-film (amorphous) solar panels. The first two are mostly solar panels used in residential, commercial, and industrial rooftop solar systems. Typically, a 6-kW solar system will require 15 solar panels, but this number may increase or decrease depending on their efficiency and type. This is because mono panels are more efficient than poly panels.

8. Utility Grid

This is the device to which the local or government electricity supply mainline is connected and then supplied to the house. It is a complex power generation, distribution, and transmission network. Energy production and delivery are managed by grid operators. Inverters are connected to this utility grid for transferring power generated by solar panels. After this, let’s learn about grid tied solar system working or grid-connected PV system working.

What is Grid Tied Solar System Working? What is Grid-Connected PV System Working?

It is a simple collection, conversion, transfer, and use a process that is grid-tied solar system working. Photons from sunlight are absorbed by solar panels that convert the heat and light energy to electric energy. Direct current (DC) generated by solar panels is transmitted to grid-tied inverters. Keep reading to know about grid-connected PV system working.

Direct current (DC) then gets converted into alternating current (AC) by an inverter. Since most appliances and devices run on AC power, an inverter is an essential component. Further, this electricity powers devices and appliances.

Excess power generated by solar panels gets transmitted to the utility grid and is stored there until further requirement. This stored energy can be used at night or on days with insufficient solar power generation. If by the end of the month, the amount of stored energy exceeds the amount of energy used from the grid, the owner gets revenue for the same. Now along with grid tied solar system components, you understand it’s working. After this, it’s time to learn about the types of grid connected PV system.

Note: The amount paid differs from country to country and is based upon the prevailing laws.

Also See: Grid Tie Inverter Working Principle

What are Advantages of Grid Tied Solar System?

After learning about grid tied solar system components, it is time to know about how advantageous this system is.

1. Saves more money with net metering: Excess power generated during the day is fed into the net meter and converted into credits that you can use for deriving power from the grid without having to pay for it

2. Utility grid acts as a virtual battery: The electricity grid is like a battery in a grid-tied system. It provides battery backup when there is insufficient power generation from panels, or at night. Unlike traditional solar batteries, the electricity grid does not require maintenance and replacements. Now, you are ready to explore the disadvantages of grid tied solar system.

Also See: 3 Amorphous Solar Panels Advantages and Disadvantages

What are Disadvantages of Grid Tied Solar System?

After learning about the advantages, it is time to know the disadvantages of grid tied solar system too-

1. Grid dependency: On-grid or grid-tied solar system is dependent on the grid for power storage. Grid is an important component in the working of this system. On-grid solar systems cannot work without a grid connection.

2. High initial installation cost: Highly efficient solar panels are required for the system along with other components like inverter, racking, and other electrical devices. All these increase the initial installation cost of the system.

Also See: 5 Major Disadvantages of Hybrid Inverter

What is Grid Tied Solar System Cost?

Typically, an on-grid solar system costs between $12,600 and $14,000 net of the federal solar tax credit. The cost per watt in most systems is between $2.75 and $3.35 with a national average price of around $3.00.

System costs vary depending on different factors like the size of the system, location, pitch of the roof, and brand & type of solar panels. Here is a table to refer to for average grid-tied solar system cost based on system size.

System size (kilowatts)	Average system cost
4 kW	$9,100
6 kW	$12,390
8 kW	$15,960
10 kW	$19,180
12 kW	$23,100
14 kW	$26,936
16 kW	$29,860

Note: Average cost mentioned in the table is calculated after deducting Federal Solar Tax Credit Incentive.

So, today you learned about grid tied solar system components that are PV panels, inverters, charge controllers, utility grids, safety switches, racks & mounts, net meter (power meter), and combiner box. Each component has its own special functionality that helps in better output of solar power systems. Other than this, now you know the rough amount that you need to pay as grid tied solar system costs depending on its power output size.

Recommended: What is PWM Charge Controller?