Off-Grid Solar

Overview of an off grid solar system

An off-grid solar system, also known as a standalone solar system, works on the same principle as an on-grid solar system: the PV cells capture the sunlight and convert it to electricity. However, the major difference is that there’s no grid connection in the case of an off-grid solar power system. Instead, it uses batteries to store the electricity generated by the panels during sunshine hours.

The off-grid solar system price in India is higher than that of an on-grid solar system price. Besides, maintaining off-grid solar systems takes more effort (and money) because batteries are involved and they have to be replaced periodically to keep the system functioning properly.

To give you an idea of the cost, here are some demonstrative rates:

• 3 kW off-grid solar system price in India: *Rs. 2,70,000 onwards
• 5 kW off-grid solar system price in India: *Rs. 4,80,000 onwards

*Please note: The off-grid solar panel prices listed above are standard market estimates.

Ready to explore the workings of an off-grid solar system, all the price details, and whether you need to invest in off-grid solar as an Indian homeowner, especially because the Indian government offers a subsidy for the installation of an on-grid rooftop solar system? 

What is an Off-Grid Solar System?

An off-grid solar system is a standalone set-up that produces and stores electricity without any connection to the public utility grid. How? It stores the power it generates in batteries.

It’s a careful set-up of the following components that work in tandem to produce electricity from sunlight:

• Solar panels (modules)
• Mounting structures
• Batteries
• Solar charge controller
• Solar inverter
• Solar accessories

When to Use an Off-Grid Solar Panel System?

Most Indian homes do not require off-grid solar systems, as their power consumption needs are met by on-grid rooftop solar systems, which are much cheaper and easier to maintain.

However, you will need an off-grid solar system in the following situations:

• You live in a remote area with no utility grid
• Your area faces extreme power cuts, and the grid is unreliable

However, if you live in an area with a reliable grid connection, the benefits of an on-grid solar system are unbeatable!

What Are the Off-grid Solar System Components?

Let us understand the role of the various components of an off-grid solar system, in electricity generation:

1. Solar panels

Solar panels are made up of solar cells.

• When they’re made of one single silicon crystal, the resulting panel is monocrystalline.
• When they’re made of multiple silicon crystals, the resulting panel is polycrystalline (multi crystalline).
• When they have solar panels on the front as well as the rear, the resulting panel is bifacial.

Off-grid solar panels trap sunlight and convert it into DC electricity. The one thing that should be taken care of at the time of installation is that shadows should not cloud the panels.

2. Solar inverter

The power from solar panels is in the form of direct current. Home appliances run on AC power. This is where the solar inverter comes into the picture. It converts DC power into AC power. An off-grid solar inverter, just like an on-grid inverter, is the heart of the solar system.

3. Batteries

Function of batteries in an Off-grid solar system

• During the sunshine hours, the electricity that the panels are producing is used to run the house.
• Whatever is extra is used to charge the batteries.
• That same power from the battery is then used to keep the house running at night.

4. Charge controller

The charge controller in an off-grid solar system controls the charge.

• The panels produce electricity.
• The electricity then goes into the charge controller.
• The charge controller feeds power into the inverter as well as uses the extra units to charge the batteries

5. Mounting structures

You have the panels and the inverter, but the system cannot be set up without proper mounting structures. The mounting structures should be at a proper tilt angle (near perpendicular to the sun for as long as possible) so that they receive maximum sunlight.

6. Solar accessories

You know the major components of an off-grid solar system, but there are other accessories without which the system will not be safe. Here are the accessories we’re talking about:

• DC cables and DC combiner box
• AC cables and AC combiner box
• MC4 connectors
• Earthing strips and conduit trays
• Lightning arrester

How Does Off-Grid Solar Work?

A combination of numerous electrical components leads to production of electricity from sunlight in a usable form (AC). Let us see the step-by-step breakdown of this process for easy understanding.

Step 1: Sunlight Absorption & Electron Excitation Through Solar Panels

Each solar panel is packed with photovoltaic (PV) cells made of semiconductor materials, typically silicon.

When sunlight (photons) hits a PV cell:

• It transfers energy to electrons in the semiconductor’s atoms, freeing them from their bonds.
• These loose electrons flow through the material to produce a direct current (DC) electric charge.
• Solar panels are wired in series (strings) to boost voltage and in parallel to boost current, optimizing the total power output for your system’s voltage requirements.

Step 2: String Aggregation & Safety Protection Through a Combiner Box

Because most off-grid solar installations use multiple strings of panels, a combiner box serves as the point where each string’s positive and negative outputs meet.

Inside, individual fuses or circuit breakers protect each string:

• If one string develops a fault (like shading damage), only that string is disconnected, keeping the rest of the array functional.
• The combiner box provides a convenient place to measure total array voltage and install a main shut-off switch for maintenance and emergency isolation.

Step 3: Maximum Power Point Tracking & Charge Regulation Through a Solar Charge Controller

The DC power from the combiner box flows into the solar charge controller that has a twofold job:

1. MPPT (Maximum Power Point Tracking): Solar panels have a sweet spot where voltage and current combine to give maximum power. The controller continuously samples the panel output and adjusts the electrical load to keep the panels operating at that optimal point, often boosting voltage (step-up) or reducing it (step-down) to match battery input needs.
2. Charge Staging: Batteries have specific charging phases: bulk (fast charge at high current), absorption (constant voltage to top off), and float (low maintenance voltage). The controller moves smoothly through these stages, ensuring batteries are neither undercharged (which reduces capacity) nor overcharged (which damages plates and electrolyte).

Step 4: Battery Bank Charging

Regulated DC current enters the battery bank, which can be made of lead-acid or lithium-ion. Each type has its own voltage profile and charging algorithm:

• Lead-acid Batteries: Sensitive to overcharging and sulfation. They require precise absorption and float voltages.
• Lithium-ion Batteries: Needs strict voltage cutoffs and temperature monitoring. They have a flat discharge curve but demand accurate cell balancing.

Step 5: Intelligent Coordination (Controller ↔ Inverter Communication)

Modern off-grid inverters and charge controllers communicate. They share real-time metrics like battery voltage, SoC, load demand, and temperature. Clearly, the inverter knows when it’s safe to draw power and when to throttle back.

If the battery SoC falls below a configured threshold, the controller can signal the inverter to shed non-critical loads or shut down entirely. This protects batteries from deep discharge, which would shorten their lifespan.

Modern off-grid inverters usually have built-in charge controllers.

Step 6: DC-to-AC Conversion Through an Off-Grid Inverter

The inverter transforms DC from the batteries into alternating current (AC) that matches household standards.

A high-quality pure sine-wave inverter:

• Uses high-frequency switching transformers to shape smooth voltage and current waveforms. This ensures compatibility with sensitive electronics.
• Monitors its own temperature, load levels, and battery input to prevent overheating.
• May include overload protection and automatic shutdown for fault conditions.

Step 7: Household Power Delivery

At last, the inverter’s AC output is fed into a dedicated breaker panel or integrated with the home’s main distribution board via an Automatic Transfer Switch (ATS).

The ATS ensures seamless handover between solar-battery power and a backup generator.

• From the panel, circuits deliver electricity to lights, appliances, and electronics.
• Advanced systems include load management features that prioritize critical circuits (like refrigeration or medical devices) and shed non-essential loads during periods of low battery charge.

What’s the Off-Grid Solar System Price in India in 2025?

The off-grid solar system price in India varies based on factors such as:

• The system capacity
• The type of solar panels
• The type of solar inverter
• Types of batteries (12 volt, 24 volt, or 48 volt)

What About Off-Grid Solar System Subsidy?

The Indian government does not offer a subsidy on off-grid solar systems under the PM Surya Ghar Muft Bijli Yojana. You need to install an on-grid rooftop solar system to receive the financial assistance the government offers in the form of a subsidy.

Let us check out the off-grid solar system price based on system capacity:

*Please note :  The off-grid solar system prices listed above are standard market estimates.

Advantages and Disadvantages of Installing Off-Grid Solar Systems in India?

Here’s a clear breakdown of the benefits of installing off-grid solar power systems in India:

• Power Where You Need It: An off-grid solar system is the only option in rural areas where there is no grid
• Zero-emission Energy Source: Off-grid solar power is clean and green. Not only does it power homes where there’s no grid, but it also ensures that no pollution is being caused in lieu of generating electricity.

Let us now understand the limitation of the off-grid solar system’s ROI

ROI (return on investment) in the case of off-grid solar systems takes more time than an on-grid system of the same capacity because the batteries are expensive.

• Usually, the off-grid solar system price breaks even in about 6-7 years.
• In the case of an on-grid solar system, the price breaks even in 3-5 years.

Here are a few other limitations of installing off-grid solar in India:

• Repeated investment in batteries since they have to be replaced after their life is over
• Higher maintenance cost since they have to be replaced after their life is over
• There’s no subsidy offered to bring down the cost of installing off-grid solar systems

On-Grid vs Off-Grid Solar: Which is Better and Why?

This is a major debate, but the choice is simple. If you live in an area with a reliable grid, you should opt for an on-grid solar system because:

• It costs less than off-grid solar
• It requires less maintenance since batteries are not involved
• The government offers a handsome subsidy for installing on-grid solar, ranging between Rs. 30,000 and Rs. 78,000 (based on the system capacity being installed)
• If your system generates more power than what you consume, you earn credits from your discom.

Conclusion

Installing an off-grid solar system in India is the best way to light up homes in rural/semi-urban areas with no (or unreliable) power grid. The electricity generated can light up homes without causing pollution.

While the off-grid solar system prices in general are higher than that of an on-grid solar system, investing in an off-grid system is worth it when the govt. power grid is not available. 

FAQs

Q. How much does an off-grid solar system cost?

A. The off-grid solar system price in India depends on many factors, such as the type of solar panels and inverters you choose.

If we had to give a ballpark range, here’s what the off-grid solar system price would look like:

• 2 kW off-grid solar system price in India: *Rs. 1,80,000 onwards
• 3 kW off-grid solar system price in India: *Rs. 2,70,000 onwards
• 4 kW off-grid solar system price in India: *Rs. 3,40,000 onwards
• 5 kW off-grid solar system price in India: *Rs. 4,80,000 onwards
• 10 kW off-grid solar system price in India: *Rs. 7,50,000 onwards

*Please note: The off-grid solar panel prices listed above are standard market estimates only.

Q. What is the disadvantage of off-grid solar?

A. It takes a lot of time for you to recover the initial investment. The ROI on off-grid solar is usually 6-7 years.

Q. Is there a subsidy for off-grid solar systems?

A. No. The Indian government offers homeowners a subsidy under the PM Surya Ghar Muft Bijli Yojana for installing on-grid rooftop solar systems, not off-grid solar.

Q. How many batteries are required for off-grid solar systems?

A. This is subjective and depends upon the size of the off-grid solar system being installed.

Although, an estimated number batteries recommended:

• Batteries needed for a 3 kW off-grid solar system: 8-9 batteries of 100 AH capacity.
• Batteries needed for a 5 kW off-grid solar system: 10-11 batteries of 150 AH capacity.