Solar Solutions Buying Guide
Explore our comprehensive guide on On-Grid and Off-Grid solar systems. Understand the differences, check specifications, and find out the exact roof area required for installation.
On-Grid Solar System
An on-grid solar system is also known as a grid-tied system since it is connected directly to the main utility grid through a bi-directional net meter. Most Indian homes with a reliable grid connection choose on-grid solar since this system is powerful enough to support all household energy requirements and is highly cost-effective.
How it Works & Components
The system consists of solar panels, a grid-tied solar inverter, module mounting structures, and a net meter. Solar panels absorb sunlight and convert it into DC electricity. The solar inverter then converts this DC into usable AC power for your home.
If your panels generate more electricity than you consume during the day, the excess power is automatically exported to the utility grid. The net meter records this, and you get credits on your electricity bill, often reducing it to zero!
Subsidy & ROI
Under the central government’s PM Surya Ghar Muft Bijli Yojana, homeowners can avail of subsidies up to ₹78,000 for installing an on-grid system. Because there are no expensive batteries to replace, the Return on Investment (ROI) is incredibly fast—typically 3 to 5 years, after which you enjoy free electricity for the remaining 20+ years of the system's life.
On-Grid Solar Specifications
| System Capacity | Approx. Units Generated / Year | Subsidy Available (PM Surya Ghar) | Best Suited For |
|---|---|---|---|
| 3 kW | ~ 4,320 Units | Up to ₹78,000 | Small homes (1-2 ACs) |
| 5 kW | ~ 7,200 Units | Up to ₹78,000 | Medium homes (2-3 ACs) |
| 10 kW | ~ 14,400 Units | Up to ₹78,000 | Large homes / Villas |
Off-Grid Solar System
An off-grid solar system is completely disconnected from the traditional power grid. This means it relies entirely on solar energy and a robust battery bank to store power for use during the night or on cloudy days. It is the perfect solution for remote areas with frequent power cuts or no grid connectivity at all.
How it Works & Components
The core components include solar panels, a Power Conditioning Unit (PCU) or off-grid inverter, and a high-capacity battery bank (such as Tubular Lead-Acid or Lithium-ion). During the day, the solar panels generate electricity to run your home appliances while simultaneously charging the batteries. Once the sun goes down, the PCU automatically draws power from the batteries, ensuring a seamless, uninterrupted power supply.
Energy Independence
With an off-grid system, you become 100% self-reliant. However, it’s important to note that off-grid systems are generally more expensive due to the cost of the battery bank, and they usually do not qualify for the standard government rooftop subsidies. Careful load management is essential to ensure your critical appliances run smoothly throughout the night.
Off-Grid Solar Specifications
| System Capacity | Typical Battery Bank | Average Backup Time | Suitable Loads |
|---|---|---|---|
| 1 kW - 2 kW | 2 to 4 Batteries (150Ah) | 4 - 6 Hours | Lights, Fans, TV, PC |
| 3 kW - 5 kW | 4 to 8 Batteries (150Ah) | 6 - 8 Hours | Basic loads + Fridge, 1 Inverter AC |
| 7.5 kW - 10 kW | 8 to 15 Batteries (150Ah) | 8+ Hours | Heavy loads, Multiple ACs, Water Pumps |
Hybrid Solar System
What is a hybrid solar system?
A hybrid solar system is a solar power setup that combines solar panels, battery storage, and a grid connection. It allows homes or businesses to use solar energy during the day, store excess electricity in batteries, and draw power from the grid when needed.
In simple terms, a hybrid solar system works both on-grid and off-grid. It uses smart energy management to automatically switch between solar, battery, and grid power, ensuring reliable electricity supply for residential and commercial use.
Extra Benefit: Because it is grid-connected, a hybrid system allows you to export surplus power back to the grid for credits (Net Metering), while still maintaining a robust battery backup for when the grid fails. It offers the ultimate energy independence and flexibility.
Uses of hybrid solar system
Hybrid solar systems are commonly used for:
- Continuous power supply for homes, especially in areas with frequent outages
- Supporting commercial buildings and small businesses with reliable electricity
- Providing solar plus battery backup for essential appliances
- Reducing electricity bills by maximising solar consumption
- Storing energy for use during peak hours or nighttime
- Improving energy reliability in regions with unstable grid supply
Examples of hybrid solar system
Some practical hybrid solar system examples include:
- Residential rooftop solar systems with battery backup for evening use (can cover 50–70% of daily household load)
- Commercial offices using hybrid systems to maintain operations during outages
- Rural clinics or schools installing solar-battery systems for dependable power
- Apartment buildings combining solar panels, hybrid inverters, and batteries
- Small businesses using hybrid solar to reduce dependence on diesel generators
Hybrid Solar Specifications
| System Capacity | Typical Battery Bank | Grid Connection | Best Suited For |
|---|---|---|---|
| 3 kW | 2 - 4 Batteries | Yes (Net Metering) | Small homes with frequent grid outages |
| 5 kW | 4 - 8 Batteries | Yes (Net Metering) | Medium homes wanting night backup |
| 10 kW+ | 8 - 15+ Batteries | Yes (Net Metering) | Villas / Businesses needing high reliability |
Area of Solar Panel Installation
Wondering how much roof space you need? Standard high-efficiency solar panels require a specific amount of shadow-free rooftop area to generate maximum power. Below is a specification guide to help you calculate your space requirements.
| System Capacity | Number of Panels (Approx. 540W/550W) | Shadow-Free Area Required (Sq. Ft.) | Shadow-Free Area Required (Sq. Meters) |
|---|---|---|---|
| 1 kW | 2 Panels | ~ 100 Sq. Ft. | ~ 10 Sq. Mtrs |
| 3 kW | 6 Panels | ~ 300 Sq. Ft. | ~ 30 Sq. Mtrs |
| 5 kW | 10 Panels | ~ 500 Sq. Ft. | ~ 50 Sq. Mtrs |
| 10 kW | 19 - 20 Panels | ~ 1000 Sq. Ft. | ~ 100 Sq. Mtrs |
*Note: The exact number of panels and space required may vary slightly depending on the specific wattage of the solar panels used (e.g., Mono PERC vs. TopCon) and the layout of your roof. Always ensure the area is free from shadows cast by trees, water tanks, or neighboring buildings.