Choosing the right commercial solar system has many great perks.

Solar power has become an attractive investment option for businesses across Perth and throughout Western Australia.


How much energy will commercial solar panels in Perth generate?

Generally, a solar PV system in Perth will generate on average 5.3kWh (kilowatt-hours) of energy per kilowatt of capacity per day on average throughout the entire year. This is based on 30 years of sunlight data from the Bureau of Meteorology.

Therefore, this means on average a 10kW solar system will generate around 53kWh of energy per day, whilst a 100kW solar system will generate around 530kWh per day (with less in winter and more in summer months. Actual energy yields will vary depending on your location, orientation/tilt angle and the components used. The below table shows the expected output from typical commercial solar system sizes.


Commercial Electrical - Choosing the Right Commercial Solar System


Westsun Solar’s engineers will review your power bills with you, whilst providing a detailed summary of the optimal size system and expected savings through the life of your commercial system.


Connecting your Commercial Solar System with Western Power

Systems under 30kW

For smaller commercial systems that are less than 10kW per phase, there is a streamlined and no cost application process with Western Power. Westsun Solar can complete this process for you.


Solar Power Systems between 30kW and 150kW

The cost to install systems with an inverter capacity over 30kW in Perth significantly increases due to the mandatory connection requirements from Wester Power. Western Power own and operate the electrical network that covers Perth and surrounding areas. For systems between 30kW and 150kW there is an enquiry and application costs of $5,250 plus the costs of an engineering study and a requirement to install a Grid Protection Unit (GPU). In total this usually adds around $12,000 to $18,000 to the cost of installing a Solar PV system. As a result, systems with a 39kW DC (solar panel rating) with a 30kVa inverter are very common to streamline the application process and avoid additional costs which don’t provide any benefits to the business.


Solar Power Systems over 150kW

Solar Panel Systems over 150kW in inverter capacity are subject to the same requirements as systems between 30kW and 150kW, although have a slightly higher upfront application and enquiry cost of $8,500. After the engineering review by Western Power, larger systems are often subject to specific design requirement of export limitation or the requirement to install SCADA network protection which can affect the ROI of a project. Westsun Solar have over 10 years experience dealing with and navigating these requirements.


Commercial solar system pricing in Western Australia and Perth

Below you can see the costs of solar systems over 30kW in Perth.


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Financing for Commercial Solar Systems in WA

There are a number of different ways that you can finance your solar system in Australia which can provide you with a positive cash flow from day one with zero upfront costs. Below are the three most common options:


Rent to own (operating lease)
  • Solar system is rented to business for certain term meaning repayments are deductible
  • Current tax rules deem that asset is on balance sheet
  • Business makes an offer to buy at end of term (usually 2 months or repayments) to acquire asset

General Terms

  • 3% to 6%
  • 2 to 10 years


Chattel Mortgage
  • Solar system becomes colateral for loan
  • Full ownership (and depreciation benefits) from day one

General Terms

  • 3% to 6%
  • 2 to 10 years


Power Purchase Agreement
  • Business only pays for the energy produced by solar at a lower rate than what they are paying their retailer
  • Only financing method where asset is off balance sheet
  • Responsibility to maintain asset remains with ppa provider through term of agreement


General Terms

  • 8c per kWh to 15c per kWh
  • 7 to 30 years


Two things to get right on your commercial solar project

Commercial solar projects follow rigorous procurement processes, making it important that you ensure you have a solid approach that will lead to a great solar investment.


1. Independent financial model to confirm feasibility and ROI

The environmental benefits of solar project are clear, however most commercial projects come down to an evaluation of the financial attractiveness of the overall project. Westsun Solar will help develop the financial model with our experienced photovoltaic engineers who have over 10 years experience within the solar industry.


2. Understanding federal solar rebates

Commercial solar prices are at all time lows in Australia, partially due to the federal government solar subsidies available through Australia’s Renewable Energy Target (RET). Solar systems up to 100kW of solar PV, the RET provides an up-front incentive in the form of STCs (small scale technology certificates. Whilst systems larger than 100kW, the RET provides an ongoing incentive (until 2030) in the form of Large-scale Technology Certificates (LGCs).

At Westsun Solar we have over 10 years industry experience and we understand choosing the right commercial solar system can be difficult. We strive to provide our customers with as much information as possible, ensuring their solar journey is as smooth as possible. We are Perth’s leading commercial solar specialists and are always here to help. Contact us today to find out everything you need to know about commercial solar.