Installing solar systems to generate electricity is an efficient way to reduce dependency on fossil fuels and the expensive electricity they generate. Two kinds of solar systems are widely popular in India – grid-tied and off-grid systems.
The choice between the two matters a lot. If you’ve been thinking about going solar too, you must know that although an off grid solar system serves the same purpose as the on-grid system, they function differently.
Dive in to decode the differences between an on-grid and an off grid PV system so that you choose the best one according to your needs.
What is an off grid solar system – how does it work?
An off grid system is a standalone system that has no connection with the electricity grid at all. It is made up of many components.
Have a look at its functioning here
- Solar panels capture sunlight and transform it into DC electricity
- A solar inverter converts that DC energy into AC electricity
- AC electricity runs the household appliances
- Excess power is used to charge the battery
- Power stored in the battery is used to run the appliances at night
What is an on-grid solar system – how does it work?
An on-grid solar system is also popularly known as a grid-tied system. Unlike a battery in an off grid solar system, it doesn’t have batteries. It’s connected to the grid.
Here’s how it functions to run appliances at home.
- The solar inverter turns DC electricity generated by solar panels into AC electricity
- The AC power runs household appliances
- The excess power is supplied to the grid
- At night, power from the grid is imported to keep the house running
- There’s a net meter that keeps a record of this electricity to and fro
- If you import more units than you export, you pay the discom for the extra units you use
- If you supply more units, the discom gives you credit
Which solar system should you choose?
It’s a million-dollar question – how do I decide which solar system is best for me?
And the answer is you need to evaluate your needs.
An on-grid solar system is the best choice for city dwellers. If your power grid is reliable and you do not witness long power cuts, installing an on-grid system is better.
On the other hand, if you live in remote areas where the grid supply is highly unreliable or the distribution lines have yet to reach your place, installing an off grid solar system is the only option.
Here is the list of the differences between these two solar systems.
|Off grid solar system||On grid solar system|
|The excess electricity is stored in a battery||The excess electricity is transferred to the grid|
|It is expensive since it requires a battery to work||It is comparatively cheaper since there’s no battery involved|
|It does not witness power outages since it’s not connected to the grid||It witnesses power outages during a power cut. This safety feature is known as anti-islanding. The plant does not supply electricity for the safety of linemen who might be working on the site of fault|
|It is best suited in remote areas where there’s no grid||It is best suited for homes in urban areas with a reliable grid|
Things to consider when installing an off grid solar system
Installing an off grid solar system is a one-time investment. Since it costs a few lakhs, you must remember certain things.
- Choose a reputable, experienced solar installation company
- Buy the correct battery size that can store the power required to fulfil your needs
- Ensure that you maintain the system with the help of professionals. Usually, installation companies offer periodic maintenance services
Installing an off grid solar system requires investment. You should be very careful about the vendor you choose. The installation cost is usually recovered in 6-7 years. And tier-1, high-quality solar panels last for at least 25 years. Which means you can get electricity from solar for decades.
1. How does an off grid solar system work?
An off grid PV system has different components that work together to produce electricity from sunlight.
Here is a brief description of how this solar system works
- Solar panels, mounted on top of solar panel stands, are installed in such a way that they get maximum exposure to direct sunlight
- PV cells in solar panels convert the sunlight into DC electricity
- DC electricity is not used to run household appliances. So, a solar inverter converts DC power into AC power
- The AC power runs the appliances, and excess power charges the battery
- The power in the battery keeps the appliances/ devices running through the night
2. Does an off grid solar system work during the monsoons?
Yes. Although the electricity produced will be lesser than what’s generated on a bright, sunny day, it’s still produced.
Usually, a solar system produces 4 units of electricity per KW under ideal conditions.