In short
- Perth makes more solar per kW than any other city on this site, about 1,600 kWh a year, and a cold store uses 85–90% of it.
- A Perth business usually earns nothing for exports. The buyback scheme excludes commercial systems, so the return is entirely in power the site uses.
- Above 30 kVA a system leaves Western Power's basic process and goes through a non-standard connection with a technical assessment. Plan the timeline around it.
Yes, solar pays for most cold stores in Perth, and on the numbers it pays faster here than in any other capital. Long, dry, sunny summers give the highest output per kW of the five cities, and a cold store's refrigeration load is there to use it. What Perth takes away is export income, which for a cold store barely matters. This page covers what changes for a Perth site. The general case is on solar for cold storage.
| Quick facts | Cold storage solar in Perth |
|---|---|
| Distributor | Western Power (the South West Interconnected System) |
| STC zone | Zone 3, rating 1.382 |
| State help | No rebate. Buyback scheme excludes commercial systems |
| Output assumption | about 1,600 kWh per kW a year |
| What to send | one recent bill; we get the interval data from it |
What's different in Perth?
1. Western Power, and the 30 kVA line
Perth's cold stores cluster around the airport and the freight routes: Kewdale, Welshpool, Hazelmere, Canning Vale and Jandakot, with the market-linked stores near Canning Vale's produce market. All of it is Western Power's network, on the South West Interconnected System, which runs on its own rules. Nothing about the process matches the eastern states.
- Up to 30 kVA of inverter capacity: Western Power's basic embedded generator process.
- Above 30 kVA: a non-standard connection, with a technical assessment of the feeder the site sits on and application fees to match. Every cold store system of real size goes through this. Expect a longer approval and plan the install date around it.
- Above 100kW: the same non-standard process, with export limiting common on constrained parts of the network. A cold store sized to its load can run with exports capped at zero and lose almost nothing.
The Perth commercial solar page has more on Western Power connections.
2. STC zone 3
Perth postcodes sit in STC zone 3, rating 1.382. For a 2026 install the scheme counts five years, so a 100kW system earns 100 × 1.382 × 5 = 691 certificates, rounded down. The zone table is on the Clean Energy Regulator's site. Since 1 October 2026 the discount covers eligible systems up to 1MW.
3. No rebate, and no export income
There is no Western Australian rebate for commercial solar. The Distributed Energy Buyback Scheme covers residential, not-for-profit and educational customers with systems of 5kW or less, so a commercial cold store gets nothing from it. Any payment for exports comes down to the retail contract, and it is usually small or nothing. That is why the example below counts exports at zero. For a cold store, which exports little anyway, it changes the result by less than 2%.
4. The best sun of the five cities
Perth's summers are long, hot and dry, with clear skies from November to March, and the refrigeration load tracks the heat. As general knowledge, a Perth roof makes about 1,600 kWh per kW a year against Brisbane's 1,450 and Melbourne's 1,250, so the same 100kW system earns more here than anywhere else on this site. The combination of the highest output and a load that uses it is the best case for cold storage solar in the country.
A worked example for a Perth cold store
Here is a worked example with made-up figures. These are example figures, not our prices or a real site. The price is the one our commercial solar cost page uses for a 100kW system.
- A 100kW system in Perth, assumed to make about 1,600 kWh per kW a year, so about 160,000 kWh a year.
- The cold store uses about 90% of that itself, 144,000 kWh, because refrigeration runs around the clock. 16,000 kWh goes to the grid.
- At $0.28 for each kWh the site no longer buys: 144,000 × $0.28 = $40,320. Exports are counted at $0, because a Perth business usually earns nothing for them (see below).
- Yearly saving $40,320. At an example price of $73,000 after the STC discount, that pays back in about 1.8 years.
Counting the 16,000 kWh of export at $0.05 instead would add $800 a year and leave the payback at about 1.8 years. In Perth, don't count on it.
What to send
Just one recent electricity bill, every page. Using the meter number on it, we get your interval data, which shows the day and night split, the summer peaks and the demand charge. You don't need to request anything from your retailer.
If you know them, mention the number of compressors, the defrost schedule and whether the roof is insulated panel. Send a bill and an accredited installer prepares a costed proposal sized to how your site uses power. Already have a quote? Compare it line by line with our checklist, starting with whether it counts export income a Perth business won't receive.