Installing a solar power system is a long-term investment that will serve you for years. For most first-timers, choosing the right solar system is a rather daunting task due to the many factors involved in the process.
One crucial question in most scenarios is whether you should choose an off-grid or an on-grid solar system for your home or housing society.
Before we dive deep into the subject and unravel how an on-grid solar system is different from an off-grid system, let’s understand what they are and how they function.
What is an on-grid Solar Power System?
In general terms, an on-grid solar system, aka a grid-tied system, is an arrangement where the system is connected to the external utility grid. In such a system, the electricity generated by solar panels remains routed to the grid.
How Does It Work?
The solar modules in the on-grid solar system constantly absorb the sunlight and turn it into Direct Current (DC). This current then goes to the solar inverter, which changes it into Alternating Current (AC). Electricity can now be used to power electronic devices for day-to-day use.
Further, there’s a bidirectional meter that:
- Transfers the energy that isn’t being used in real-time to the utility grid.
- Imports electricity from the grid at night to power the load.
- Records the unit exchange.
What is an Off Grid Solar Power System?
In contrast to an on-grid solar system, an off-grid solar system is not linked to a utility power grid and, thus, requires a battery unit to function. These units are perfect for use cases where a utility power grid is unavailable.
How Does it Work?
This autonomous system includes solar panels, a charge regulator, an inverter, and a battery. The journey of power generation in this system, too, begins with solar panels absorbing sunlight. The extra power generated charges the batteries during the daytime.
The power that is stored in batteries during the day is used at night to keep the load running.
Top 4 Differences Between Off-Grid and On-Grid Solar Systems
1. Electricity Access
Generally, when you opt for an off-grid solar system, you rely upon upon the shining sun and the power stored in the integrated batteries for power supply. If someday the battery doesn’t have enough charge during the night, the power supply will be interrupted.
On the other hand, thanks to the availability of a power grid outside the unit, an on-grid solar system will provide you with a constant electricity supply. If for any reason, your solar power system isn’t churning out enough power, you can always supplement it via the utility grid.
- Excess Power:
Off-grid solar power systems generally have the functionality to generate a little extra power than needed. This extra energy is stored in the batteries and is used to run the load at night.
If you opt for an off-grid system, you may consider your energy goals and select the size accordingly.
Much like off-grid solar systems, the mechanism of an on-grid solar system is also designed to produce some extra energy.
However, as it lacks battery support, the extra power goes straight to the power grid. Later, at night, the bi-directional meter imports power from the grid and run the load. This back-and-forth of energy is also known as net metering in technical terms.
- Power Outage:
As an off-grid solar system works independently of a utility grid, you wouldn’t notice that the power is gone as long as enough energy is stored in your battery.
Whereas, if a bad storm hits the city and there’s a power cut, the anti-islanding feature of the on-grid system triggers and shuts down the power supply from the panels.
While you won’t have access to electricity during power cuts, you are on a grid solar system and will suffer no damage.
Both options, of course, come with their pros and cons. But if you need a relatively failsafe solution and you don’t mind increasing your budget, you may invest in an on-grid solar system with battery backup.
- Return on Investment (ROI)
When making a long-term investment, ROI becomes a crucial factor to consider. For an on-grid system, the break-even point comes after 3 to 5 years of installation. Whereas, in the case of an off-grid system, achieving a break-even point can take up to 6 to 7 years.
All things considered, choosing an on-grid or off-grid solar system depends entirely on your needs and preferences.
However, most individuals prefer an on-grid solar system as it doesn’t require them to purchase expensive additional batteries. Also, having a grid down is rare, making the grid system more reliable.
- What are some primary advantages of an on-grid solar system?
While the list of benefits of on-grid solar systems is exhaustive, here are some of the primary reasons why you should consider switching to on-grid solar power:
- Massive reduction in electricity bills (up to 90%)
- Easy maintenance
- Effective synchronization of power sources
- What are some famous use cases of off-grid solar systems?
Off-grid solar systems are most relevant where a power grid is not easily accessible. Here are some of the widespread use cases of off-grid systems:
- Providing electricity to remote areas
- Supplying emergency power during natural disasters
- Critical sea expeditions
- Providing power backup for areas where power cuts are frequent
- What is a Hybrid Solar System?
A hybrid solar system merges the goodness of both on-grid and off-grid solar systems. This means that even though the system will be attached to an external utility grid, it will still have a battery backup. The downside is, it’s more expensive.
- What is an off-grid solar power plant made of?
An off-grid solar system encompasses the following components:
- Solar panels
- Backup battery
- Charger control
- Solar Inverter
- Mounting structures
- Solar accessories
- What is the average cost of an on grid solar system?
Depending on your energy needs, the cost of an on grid solar system can vary. Refer to the following table:
|Capacity in KW||Price per KW|
|1 KW||₹45,000 to ₹70,000|
|2 KW||₹90,000 to ₹1,40,000|
|3 KW||₹1,35,000 to ₹2,10,000|
|4 KW||₹1,80,000 to ₹2,80,000|
|5 KW||₹2,25,000 to ₹3,50,000|
|10 KW||₹4,50,000 to ₹7,00,000|