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.