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A system connected to the utility grid is known as a grid-connected energy system or a grid-connected PV system.
Through this grid-tied connection, the system can capture solar energy, transform it into electrical power, and supply it to the homes where various electronic devices can use it.
When the grid-connected PV system is installed on residential or commercial rooftops, it provides solar electricity to all the electrical ports and sockets.
When excess power is produced, the bidirectional meter in the grid-tied PV system exports extra units of electricity to the grid.
Later on (at night), those exported units are imported to keep the power supply on. Also, the grid-connected PV system allows consumers the flexibility to use electricity from the grid when there is no sunlight.
This PV system has a simple design and requires minimal maintenance, making it more cost-efficient than other PV models.
Let us learn more about the grid connected PV system, its types and other aspects.
How Each Component of Grid Connected PV System Works To Generate Electricity?
There are five main components involved in the making of a grid-connected solar system.
All these components work together to generate electricity from sunlight and supply power to the household appliances after installation.
1. Solar Panels
Solar panels absorb energy from the sunlight and promptly convert it into a DC supply. That DC power is sent to a solar inverter.
2. Solar Inverter
The inverter is an essential component in the grid connected PV system. It converts the DC power it receives from the panels into AC power.
The inverter then sends the AC supply to the house so that all the connected devices can run on solar electricity.
If the system generates more power than the consumer’s requirement during the day, it is sent through the net meter and stored in the grid.
3. Net meter (bidirectional meter)
The net meter withdraws (imports) the exported units from the grid at night. It keeps all the appliances running.
This power exchange is known as net metering. The Government of India has approved and mandated this facility in every State and Union territory.
4. Grid
Grid is the quintessential part of a grid-connected PV system. It’s more of a sort of battery since that’s where excess power is sent and then taken back when needed. So, it’s basically a sort of power backup.
5. Mounting structures
Mounting structures or mounting stands are structures where the solar panels are mounted. They have to be strong enough since solar panels have weight.
A 1 KW solar system mounted on 6ft to 9ft raised mounting structures on an RCC rooftop can easily weigh anywhere between 25-30 kg/ sq meter.
Some other miscellaneous components that are equally important parts of a grid connected PV system include AC cables, DC cables, AC combiner box, DC combiner box, earthing strips and cables, and MC4 connectors.
What are the Types Of Grid Connected PV Systems?
There are two types of grid-connected solar systems:
- On-grid systems
In this type, the solar system is integrated with a grid. The structure is similar to traditional electricity infrastructure. It is the most popular and widely trusted grid connected PV system available in the market.
- On-grid systems with a battery backup
This grid-connected PV system is similar to the first one, except that it has a battery backup. It’s also known as a hybrid solar system.
The batteries store the extra electricity from the sunlight and save them for emergencies.
Compared to the first one, this photovoltaic system is more expensive as additional batteries are required to store electricity.
Grid Connected PV System Vs Off Grid PV System
Let us now explore the points of differences between grid-connected and off-grid PV systems:
| Grid Connected PV System | Off Grid PV System |
| It cannot be installed without a utility grid | It is installed without a utility grid. |
| The equipment required is a grid-tied solar inverter, solar panels, a bidirectional meter, a grid, and mounting structures | The equipment required are solar charge controller, battery bank, DC disconnect (additional), off-grid inverter, and backup generator (optional) |
| It is cost-efficient | It is comparatively costly |
| It is highly efficient as the energy is drawn directly from the sunlight | The efficiency decreases over time with the battery bank getting older |
| Less amount of energy storage is needed | A large amount of energy storage is required |
Advantages of Using a Grid-Connected PV System
A grid-connected PV system has many benefits. Some of them are as follows:
- It does not incur high maintenance charges.
- It helps to reduce electricity consumption as much of the energy is taken from sunlight. It is simple to install.
- The grid-connected PV system has a low gestation period.
- It functions without harmful carbon emissions.
- Unlike other solar system types, most models of a grid-connected PV system do not require additional batteries; and hence, are cheaper.
- A grid-connected PV solar system can be installed in vacant roof space without requiring any additional land. It’s quite reliable.
- Apart from providing the primary energy source in homes, consumers can use this system in commercial establishments, industrial units, and educational institutions.
Disadvantages of a Grid-Connected PV System
Do you know that grid-connected PV systems have certain disadvantages as well? These include:
- It cannot function without a grid. If the grid fails, the system will stop working.
- The initial installation cost is high.
- The models without a battery backup cannot provide electricity during power outages.
Price Of A Grid Connected PV System
A 1 KW grid-connected PV system can cost anywhere between Rs. 45,000 to Rs. 60,000.
The price heavily depends on the panel chosen, the cost of the inverter, the features of the PV system, the year of installation, the system size, and many other factors.
Government subsidies are available for residential rooftop installation. A 40% subsidy is offered to install a solar system between 1 KW to 3 KW. A 20% subsidy is provided to install a solar system between 4 KW to 10 KW.
Conclusion
Many people are switching to solar since a solar system reduces electricity costs and protects the environment from carbon emissions.
The grid-connected solar system is widely used for its various benefits. Although it has a few disadvantages, its benefits outweigh the cons.
FAQs
Q. What is the maximum size of a grid-connected rooftop PV system?
For most households, a 1 KW to 10 KW grid-connected PV system is enough.
In fact, an average Indian household can very well function on a 3 KW grid-tied solar system.
Q. What happens to the on-grid inverter during a power failure?
During a power failure, the on-grid inverter disconnects the photovoltaic system from the grid.
Q. How much area is needed to install a 1kW grid-connected PV system on the rooftop?
10 square meters or 100 sq feet of area is needed to install a 1 kW grid-connected rooftop PV system.
Ensure that the space is shadow-free. Also, the mounting angle and orientation (it should be true South) of the solar panels should be proper.
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