Difference between Off-Grid and On-Grid Solar Energy

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Difference between Off-Grid and On-Grid Solar Energy

Solar energy systems are commonly divided into two main categories: off-grid and on-grid solar energy. Each of these systems has its unique characteristics and applications, making it essential to understand the key differences between them. In this article, we will delve into the fundamental distinctions between off-grid and on-grid solar energy systems.

Difference #1: Your Access to Electricity

Electricity Access with Off-Grid Solar

Off-grid solar systems are not connected to the power grid and rely only on the sun and energy stored in batteries to power your home or company. If you pick an off-grid solar system without a backup generator, you will have access to electricity in the two scenarios below:

    1. When you draw electricity from a solar storage device, such as batteries, when the solar panels are not producing electricity.
    2. When the sun shines and your solar system is producing electricity.

However, if you do not have batteries or a way to store energy, you will be without power during overcast days and at night. With an off-grid setup, the electricity you generate and store in your batteries is the only source of power for your devices. When you need more power, there is no external grid to draw from. Some people complement this with a generator set, so when solar panels are not producing electricity, they can still use a generator to supply power.

Electricity Access with On-Grid Solar

In contrast, on-grid solar systems are directly connected to the electrical grid, ensuring constant access to electricity with the exception of grid interruptions. You can always get electricity, whether your solar system is producing power, or you have batteries.

If your solar system does not generate enough electricity to suit your demands, you can supplement it by pulling energy from the utility grid. This assures a consistent supply of electricity, especially during peak demand periods.

Difference #2: What Happens to Excess Production

Excess Production with Off-Grid Solar

Off-grid solar systems frequently generate excess electricity during the day, which is then stored in batteries. When the system is not producing electricity, such as at night or on overcast days, this stored energy can be used. The amount of excess energy that can be stored is determined by the size of your battery bank and your energy usage patterns.

You can size your off-grid system to create more daytime surplus electricity to cover your energy demand around the clock, depending on your energy goals. However, the unpredictability of weather, especially prolonged cloudy spells, can limit the system’s ability to charge the batteries fully. Purchasing extra batteries can mitigate this issue, but it can be costly.

Excess Production with On-Grid Solar

Excess energy generated during the day can be transferred back to the grid rather than stored in batteries in on-grid solar systems. In Singapore, government compensate for excess electricity using a system known as net metering. Net metering entitles you get credits for the electricity generated by your solar system and fed into the grid. You can utilize these credits to offset your future grid-based electricity consumption.

Difference #3: What Happens When the Grid Goes Down

Power Outages with Off-Grid Systems

Off-grid solar systems can continue to generate electricity even when the power grid is down. Because these systems function independently of the grid, you will not suffer any interruptions in your electrical supply. Your solar system remains operational, guaranteeing that you have uninterrupted power.

Power Outages with Grid-Tied Systems

Grid-tied solar systems, however, are reliant on the grid for operation. During a grid outage, these systems automatically shut down to prevent the flow of electricity onto the grid, which could pose a safety risk to utility workers repairing power lines.

If you value uninterrupted power supply during outages, you can opt for a grid-tied solar system with a battery backup. Batteries can keep your system running even when the grid is down, providing backup power and ensuring continuity during blackouts.

Difference #4: How You're Billed for Electricity

Electricity Bills with an Off-Grid System

Off-grid solar system owners typically do not receive traditional electric bills since they are not connected to the grid. However, the initial setup of off-grid systems can be more expensive due to the need for additional equipment like batteries, which are essential for energy storage.

Electricity Bills with a Grid-Tied System

Users of grid-connected solar systems may still receive reduced electricity bills, even when their solar installation caters to the entirety of their energy needs. These reduced bills are made possible by the consistent generation of solar power, which not only covers their energy consumption but also helps to lower their overall electricity costs.


In conclusion, whether you’re looking to harness the independence of off-grid solar or the convenience of on-grid solar, the decision should be tailored to your unique requirements and aspirations. To take the next step towards your sustainable energy journey, and explore the perfect solar solution for your needs, don’t hesitate to contact us. We are ready to assist you in making an informed decision and setting you on the path to reliable, eco-friendly, and cost-effective solar energy. Get in touch with us today to get started on your solar installation project!