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If you have a commercial solar or battery project between 30kVA and 1MVA anywhere on the South West Interconnected System, the way you lodge it with Western Power changes on Monday 17 August 2026. The headline is that you now pay by credit card when you submit rather than waiting for an invoice. The part that will catch more people is that the forms stop letting you lodge an incomplete submission and sort out the detail afterwards.
Western Power sent the notice to registered connection applicants on 13 August. It covers the enquiry, application and commissioning forms for Medium Distributed Energy Resources, which is the band above 30kVA and up to 1MVA. Questions go to the Distributed Energy Connections team at commercial.solar.pv@westernpower.com.au.
Medium DER form changes
Payment at submission. The applicable fee is charged by card at the point of lodgement. Western Power's stated reason is that it removes an average delay of around 10 days between a submission arriving and assessment work beginning, because the invoice-and-wait step disappears.
New forms. The enquiry, application and commissioning forms have been redesigned.
Mandatory project information. Fields Western Power treats as critical are now required rather than requested. The stated aim is fewer follow-up requests and faster assessment.
Clean Energy Council integration. The forms connect to the CEC approved inverter and battery lists, so equipment is selected from the approved list rather than typed in free text.
Card payment at lodgement
Western Power's published fees for an inverter system above 30kVA are $250 plus GST for the enquiry and $5,000 plus GST for the application. The enquiry is the feasibility gate. The application is the assessment that follows.
That means the enquiry stage barely changes. Two hundred and seventy-five dollars on a card is a rounding error against a commercial project, and paying it upfront to save ten days is a straightforward gain.
The application stage is different. From Monday, $5,500 goes on a card at the moment of lodgement, per application, before any assessment work has begun. For a business carrying two or three commercial projects at once that is real money committed earlier in the process, and it is now committed by whoever is sitting at the form. If your projects coordinator could previously lodge an application and route the invoice to accounts, that arrangement has changed. Someone needs a card with a limit that covers it and the authority to use it, and that is worth sorting out before Monday rather than at 4pm on the day a submission is due.
Fees above 200kVA depend on the assessment path Western Power assigns, so confirm the figure for your band before assuming $5,500.
Mandatory project information
The old pattern on a Medium DER application was familiar to anyone who has lodged one. You submitted with what you had, Western Power came back with questions, and the gaps closed over a few rounds of email. It felt fast at the front end and slow overall.
There is a related consequence worth thinking through. Without an off-take agreement, Western Power limits export to 5 per cent of total inverter capacity, and a National Engineering Register engineer has to be engaged. Neither of those is new, but a form that will not accept a partial answer is a form that surfaces both at lodgement rather than three weeks in.
Equipment checks at commissioning
Validating inverter and battery selection against the CEC lists is sensible at the application stage. The place it will show up is later.
A model gets substituted between design and installation more often than anyone likes to admit. Supply falls over, a distributor swaps a variant, a three-phase unit becomes two single-phase units. Under the old commissioning process a mismatch between what was approved and what went on the wall could be reconciled in correspondence. A commissioning form that validates against a list is less forgiving. If the installed equipment is not what the application named, expect to deal with it before Approval to Operate rather than after.
Bear in mind that Approval to Operate already depends on your electrical retailer submitting an ETAF form and requesting the bi-directional meter change. That dependency has not moved, and it is still the step most likely to hold up a job that is otherwise finished.
Projects awaiting commissioning
Western Power's notice is explicit on one point that is easy to skim past. If your project is already running and you have not yet submitted a commissioning form, you must use the new commissioning form once it is available on 17 August. Western Power says it will send a link when it is needed.
So a job approved months ago, installed, sitting there waiting to be commissioned, does not get to use the form it started under. Anyone with jobs in that state should count them today and work out what information the new form is going to ask for.
Preparing for the form change
For the 17 August changeover, complete project information matters more than which form you start with. An incomplete submission under the old form still needs follow-up correspondence. The new form brings that preparation forward to lodgement.
The exception is a project where card approval for the fee cannot be arranged in time. That is a reasonable reason to lodge before Monday. Wanting to avoid a new form is not.
For projects at the earlier stage of this, the connection constraint rather than the incentive is usually what decides whether a commercial roof is viable at all, which we set out in the missing middle for commercial rooftops.
Western Power publishes the current process and fees for inverter systems above 30kVA on its connections pages.