Commercial solar follows the same physics as a home system, but almost everything else is different, the sizing, the connection, the incentives and the way the return stacks up. Here's what business owners need to know.

How commercial solar differs from residential

  • It's sized to your load profile, not your roof. The goal is to match generation to when your business actually uses power, which, for most businesses, is conveniently during daylight hours.
  • Three-phase is the norm. Most commercial sites run three-phase power, which allows much larger systems and higher export limits than a single-phase home.
  • Self-consumption drives the return. Because businesses typically use most of their power during the day, a high proportion of generation is used on site rather than exported, which is where the value is.

The incentive threshold: 100kW

The federal Small-scale Renewable Energy Scheme covers systems up to 100kW of inverter capacity. Because panel arrays can be oversized above the inverter rating by up to about 33%, that threshold allows for roughly 133kW of panels while still qualifying for small-scale technology certificates (STCs), applied as an upfront discount.

Above that threshold, systems shift to large-scale generation certificates (LGCs), which work as ongoing credits generated over the life of the system rather than a single upfront discount. Eligibility criteria apply to both. EFS Solar is not affiliated with any government body.

See our solar & battery rebates guide for current figures.

What size does a business need?

Sizing starts with your interval data or bills. We look at how much you use, and critically when you use it. A site running machinery from 7am to 5pm has a very different profile to one with evening peaks. From there, roof space (or ground-mount area) and your connection type set the practical ceiling.

For a sense of how system sizes scale, our guide to solar system sizes covers the range from small systems up to the largest configurations.

Payback for a business

Commercial payback is often faster than residential because of that high daytime self-consumption, but it depends on your usage, tariff, system size and real-world output. There can also be tax treatment worth discussing with your accountant. Any payback figure we give you is an estimate with the assumptions written down, actual results vary.

Talk to us about your site

Every commercial site is different. Explore commercial solar or request a free assessment, we'll review your load profile, confirm your connection and network rules, and design a system sized to what genuinely benefits your business.

About this guide: thresholds and mechanisms described are general guidance as at July 2026 and depend on your specific system, site and network rules. It's not a quote or financial advice.