When does a system count as large-scale in WA?

In practice the large-scale territory starts around 100kW and runs up into the megawatt range. Below roughly 100kW a system is usually treated as a standard commercial install with a simpler connection. Above it, Western Power requires network studies, the certificate pathway changes and structural engineering is more involved. We confirm where your proposed system sits during feasibility, because the threshold affects approvals, metering and the overall timeline.

How long does a large commercial solar project take?

The install itself is often the shorter part. Approvals and any structural or metering work usually set the overall timeline, and these can run across several months at this scale. We give you a realistic schedule after feasibility and keep you updated as each stage clears, so you can plan deliveries, access and any shutdown around it with confidence.

How do large-scale certificates differ from a small system?

Smaller systems (broadly under 100kW) generally use Small-scale Technology Certificates, or STCs, claimed upfront as a discount on install cost. Larger systems instead qualify for Large-scale Generation Certificates, or LGCs, created from metered output over time and sold as the system generates. Crossing the threshold moves you from an upfront deduction to an ongoing revenue stream, which changes how the financial model is built. We explain which pathway applies to your size during design.

What are the main downsides or risks to plan for?

The biggest ones sit with the network: Western Power can impose export limits or require upgrades that affect returns and schedule. Savings also depend on using the power on site, so weak daytime load reduces the benefit. Roofs may need structural work before an array can go on. We surface all of these at feasibility rather than after you commit, so there are no surprises later.

What affects the cost of a large-scale solar system?

System size is the biggest driver, followed by the grid connection works Western Power requires, which can be significant at this scale. After that come structural or switchboard upgrades, inverter configuration, and rooftop versus ground-mount. Export limits and metering can shift the figure too. We assess all of this and provide a written quote, so you see exactly what s included rather than a rough estimate. You can contact us to start a feasibility review.

Can the system be expanded or export-limited later?

Yes. Many sites install a zero-export or export-limited system where the network can t accept full export, and plan for expansion later. We design with headroom in the cabling and switchboard where it s practical, so adding capacity or storage down the track is simpler and avoids reworking the core solar system.

Large-Scale Commercial Solar in Perth, WA

Large-scale commercial solar covers systems from around 100kW upward, where grid connection, structural engineering and energy modelling matter as much as the panels. Radiant Commercial Solar designs and delivers these projects for Perth businesses across industrial and commercial estates, from a first feasibility review through design, Western Power approvals and installation to commissioning. At this scale the project runs across several months rather than weeks, and the sections below explain why and what each stage involves.

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What a Large-Scale Solar Project Covers

Grid Connection and Approvals

At scale, the grid connection sets the timeline. We handle Western Power network studies, work out export limits or zero-export options, and arrange any metering upgrades your site needs. This is where large projects differ most from standard systems, so we scope it before committing to a design or install date.

Energy Modelling and System Design

We model your consumption against expected generation to size the solar system for your actual load, not a round number. The design sets panel count, inverter configuration and single-line diagrams, and shows how much of your daytime demand the array can realistically offset across the year in Perth conditions.

Structural and Installation Works

Large rooftop arrays need structural engineering sign-off and mounting rated for local wind loads. We coordinate the engineering reports, the mounting system and the installation itself, sequencing work to keep your site operational. Cabling, protection settings and commissioning complete the solar power system ready for connection.

Large-Scale Systems We Install

100kW+ Rooftop Systems

Systems of 100kW and above sited on large commercial and warehouse roofs. These suit businesses with high daytime consumption and plenty of unshaded roof space. We assess the roof structure and orientation first, then design the array to use the usable area efficiently while meeting load and export requirements.

Multi-Site Business Installations

Businesses running several locations can roll out solar across sites under one coordinated program. This suits retail chains, logistics operators and franchises wanting consistent reporting. We design each site to its own roof, load and connection while keeping the equipment, monitoring and documentation standard across the portfolio.

Ground-Mount Solar Arrays

Where roof space is limited or structure won’t carry the load, ground-mount arrays use available land instead. They suit sites with spare yard or paddock area and simplify access for maintenance. Choosing between rooftop and ground-mount comes down to structure, land, shading and cost, which we work through during design.

Shopping Centre and Office Solar

Shopping centres and multi-tenant office buildings have mixed loads, common areas and sometimes embedded networks to account for. These projects suit owners and managers wanting to cut common-area costs or offer solar to tenants. We design around tenancy metering and the building’s demand profile to make the solar energy count where it matters.

How a Large Solar Project Runs

Site Assessment and Feasibility

We start with your energy bills, site drawings and a visit. We check roof or land capacity, shading and switchboard, then give an early view on viable system size, likely connection route and whether export limits will apply. This sets realistic expectations before any design spend.

Design, Modelling and Approvals

We produce the detailed design, yield model and single-line diagrams, then lodge the Western Power application. Structural engineering and any metering work are organised in parallel. Approvals can take time at this scale, so we keep you informed on where each step sits and what it means for the schedule.

Installation and Site Works

With approvals in hand, we install the mounting, panels, inverters and cabling. Work is staged to limit disruption to your operation, and safety around live switchboards is managed throughout. We coordinate access, deliveries and any crane or roof works around your trading hours where possible.

Commissioning and Handover

We test the system, set protection and anti-islanding, and complete commissioning with Western Power so the system can energise and export. You receive the documentation, monitoring access and a walk-through of how generation and performance are tracked day to day.

Start Your Large-Scale Solar Project

If you run a large facility across Perth and want to know whether large-scale commercial solar stacks up for your site, start with a feasibility review. We'll look at your bills, roof or land, switchboard and likely connection, then set out a realistic system size, timeline and payback range, including any limitations, before you commit to anything. Sources: Western Power network connection requirements; Clean Energy Regulator STC and LGC guidance. Last updated February 2026.

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Why Businesses Scale Up Their Solar

Lower Energy Bills, Modelled Upfront

Because we model expected generation against your real consumption before quoting, you see how much daytime demand the solar panels can realistically offset and a payback range built on stated assumptions rather than a round promise. Tariff changes, weaker self-consumption and export curtailment can all shift the actual return, so we show the numbers behind the figure and where they could move.

How Self-Consumption Drives Returns

Exported power is paid at a lower rate than the grid power it replaces, so a large array earns most when its output is used on site as it is produced. Steady weekday operations capture the most value; heavy overnight or seasonal loads leave more to export. This trade-off is why system size is matched to your demand curve, not maximum roof area.

When Large-Scale Solar Is Worth It

Large-scale solar suits sites with high, steady daytime consumption and sound roof or land to carry it. It is a weaker fit where loads run overnight, roofs are heavily shaded or structurally limited, or the network heavily restricts export. We tell you honestly at feasibility if your site is a marginal case, before you spend on design.

Common Questions About Large-Scale Solar

When does a system count as large-scale in WA?
In practice the large-scale territory starts around 100kW and runs up into the megawatt range. Below roughly 100kW a system is usually treated as a standard commercial install with a simpler connection. Above it, Western Power requires network studies, the certificate pathway changes and structural engineering is more involved. We confirm where your proposed system sits during feasibility, because the threshold affects approvals, metering and the overall timeline.
How long does a large commercial solar project take?
The install itself is often the shorter part. Approvals and any structural or metering work usually set the overall timeline, and these can run across several months at this scale. We give you a realistic schedule after feasibility and keep you updated as each stage clears, so you can plan deliveries, access and any shutdown around it with confidence.
How do large-scale certificates differ from a small system?
Smaller systems (broadly under 100kW) generally use Small-scale Technology Certificates, or STCs, claimed upfront as a discount on install cost. Larger systems instead qualify for Large-scale Generation Certificates, or LGCs, created from metered output over time and sold as the system generates. Crossing the threshold moves you from an upfront deduction to an ongoing revenue stream, which changes how the financial model is built. We explain which pathway applies to your size during design.
What are the main downsides or risks to plan for?
The biggest ones sit with the network: Western Power can impose export limits or require upgrades that affect returns and schedule. Savings also depend on using the power on site, so weak daytime load reduces the benefit. Roofs may need structural work before an array can go on. We surface all of these at feasibility rather than after you commit, so there are no surprises later.
What affects the cost of a large-scale solar system?
System size is the biggest driver, followed by the grid connection works Western Power requires, which can be significant at this scale. After that come structural or switchboard upgrades, inverter configuration, and rooftop versus ground-mount. Export limits and metering can shift the figure too. We assess all of this and provide a written quote, so you see exactly what’s included rather than a rough estimate. You can contact us to start a feasibility review.
Can the system be expanded or export-limited later?
Yes. Many sites install a zero-export or export-limited system where the network can’t accept full export, and plan for expansion later. We design with headroom in the cabling and switchboard where it’s practical, so adding capacity or storage down the track is simpler and avoids reworking the core solar system.

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Request a Quote and we’ll confirm your timeline and scope—then keep you updated right through to handover.