Do you understand the relationship between an onsite solar system and grid electricity?

For businesses considering solar energy, one of the most common questions is:

How does an onsite solar system work alongside the existing grid electricity supply?

The good news is that modern onsite solar systems are designed to work seamlessly with the grid – maximising your use of solar energy – while keeping your business connected and powered at all times.

Here’s how it works…

An onsite solar system is configured to prioritise solar power first.

During daylight hours, the solar panels capture sunlight and convert it into electricity through a process called the photovoltaic effect. This electricity is then used to power your factory or commercial building.

As long as your solar system is generating power, your site will draw from it first. This means you won’t be using – or paying for – electricity from the grid while your solar system is meeting your energy needs.

For example. If your solar panels are producing 100 kWh and your building is using 80 kWh at that time, all of your power will come from solar – completely bypassing the grid – and you’ll even have 20 kWh left.

What Happens with Excess Energy?

That excess energy (in the example above, 20 kWh) doesn’t go to waste.

It can be exported back to the grid – and in many cases, your energy provider will pay you for it. This is known as an export tariff.

The rates and terms vary depending on your location and provider, but for commercial systems, this can create an additional profit stream.

To do this legally and technically, you’ll need an export agreement with your electricity provider or grid operator. This ensures that any electricity you feed into the grid is measured and compensated correctly.

What About Non-Daylight Hours?

At night or during very cloudy periods when your onsite solar system isn’t generating enough power, your building will automatically draw electricity from the grid.

This transition is seamless and instant – there’s no interruption in service.

Because of this, you still need a standard electricity supply agreement with a provider.

Solar can greatly reduce your dependence on the grid, but it doesn’t replace it entirely – especially if your business operates around the clock.

In Summary…

✅ Your building uses solar electricity first, reducing your reliance on (and costs from) the grid.

✅ You only use grid electricity when solar generation isn’t enough – at night or on very cloudy days.

✅ You’re not charged by your provider when using your own solar-generated electricity.

✅ Excess solar energy can be exported for profit – but you’ll need a grid export agreement in place.

✅ A grid connection remains essential for backup and continuity.

By installing an onsite solar system, you’re not just cutting energy costs – you’re gaining greater energy independence and creating a new asset that works for your bottom line.