Factory Solar Savings Case Study for Australian Sites

A production line does not stop when electricity prices rise. For Australian manufacturers, that makes energy one of the few operating costs that can affect margins every day without delivering a better product. This factory solar savings case study uses a realistic manufacturing scenario to show how a well-designed commercial solar system can reduce daytime grid purchases, manage demand charges and create more predictable energy costs.

The figures are illustrative rather than a guarantee. Actual savings depend on the factory’s location, operating hours, roof condition, tariff, equipment load profile and available incentives. That detail is precisely why a site-specific assessment matters.

Factory solar savings case study: a practical model

Consider a medium-sized manufacturing facility operating six days a week in regional New South Wales. The factory runs machinery from 6:00 am to 4:00 pm, with compressors, refrigeration, extraction systems and process equipment creating a substantial daytime electrical load.

Before solar, the site consumed approximately 1.4 gigawatt-hours of electricity a year. Its bills included more than just energy usage. The business paid for electricity consumed in kilowatt-hours, but also faced network and demand-related charges associated with periods of high site demand. This is common for commercial and industrial facilities, where a brief peak can have a disproportionate effect on annual costs.

The business had a large, mostly unshaded roof and a predictable daytime load. Those two factors made rooftop solar a strong fit. After reviewing interval data, roof layout and future production plans, the proposed system was a 500 kW commercial solar installation.

The production and self-consumption picture

In this example, the 500 kW system produces around 700 megawatt-hours a year. Solar generation changes seasonally and will vary by location, panel orientation, shading and soiling, but the critical question is not simply how much it produces. It is how much power the factory can use as it is generated.

Because the site operates during daylight hours, it self-consumes an estimated 82 per cent of solar generation. That means roughly 574 megawatt-hours of electricity is used directly by the factory rather than purchased from the grid. The remaining generation is exported when site demand is lower than solar output.

Direct self-consumption is usually where the strongest financial value sits. Every kilowatt-hour used behind the meter can avoid the applicable retail energy charge and, depending on the tariff structure, may also reduce related network costs. Exported electricity still has value, but feed-in rates are generally lower than the cost of buying power from the grid.

How the savings stack up

For this model, assume an avoided electricity cost of 22 cents per kilowatt-hour for solar energy used on site. Direct solar consumption would then deliver about $126,000 in annual avoided energy purchases.

The exported portion of generation – approximately 126 megawatt-hours – earns a more modest credit. At an assumed export value of 6 cents per kilowatt-hour, this contributes around $7,500 a year. A carefully chosen electricity contract can affect this outcome, particularly for larger systems where export volumes are meaningful.

Solar can also reduce the factory’s grid demand during sunny periods. In this example, the system helps lower afternoon demand peaks enough to create an estimated $18,000 a year in demand-related savings. The exact result depends on how the retailer and network calculate demand charges, and whether the facility’s highest-demand periods align with solar production.

Together, the indicative annual benefit is about $151,500. That is made up of avoided grid energy, export credits and reduced demand costs. It does not assume that electricity prices stay fixed. If grid prices increase over time, the value of directly consumed solar energy may rise as well.

The result is not a promise that every 500 kW system will save the same amount. A factory running overnight, for example, may have lower daytime self-consumption. Conversely, a site with high daytime refrigeration, pumping, processing or compressed-air loads may achieve a higher solar utilisation rate.

Capital cost, incentives and payback

Commercial solar pricing is influenced by roof complexity, access, switchboard capacity, structural requirements, safety systems, panel and inverter selection, and whether network upgrades are needed. The right system is not necessarily the lowest-priced one. Downtime risk, equipment quality, installation methodology and long-term servicing all affect the true value of the investment.

For the purpose of this case study, assume the net installed cost after applicable incentives is between $520,000 and $650,000. With annual savings of about $151,500, the simple payback range is approximately 3.4 to 4.3 years.

That calculation is useful, but it is only one measure. Factory owners should also consider the system’s expected operational life, projected electricity price movements, depreciation treatment, financing costs and maintenance requirements. Solar equipment can continue producing energy well beyond its simple payback period, provided it is properly designed, monitored and maintained.

Incentives can materially change the numbers. Depending on system size, technology, location and project structure, a business may be eligible for small-scale technology certificates, large-scale generation certificates, state-based programs or other commercial arrangements. Eligibility rules and certificate values can change, so incentives should be confirmed during project planning rather than assumed from an early estimate.

Some businesses choose an outright purchase to maximise long-term returns. Others prefer solar finance or a power purchase agreement, where the project economics are assessed against a contracted energy rate and reduced upfront capital commitment. The best approach depends on cash flow, balance sheet priorities and the organisation’s appetite for asset ownership.

Why load analysis matters more than panel count

A factory can have a large roof and still be a poor candidate for an oversized system. Installing more panels than the site can use may increase low-value exports and extend the payback period. The goal is to design for the facility’s actual electricity profile, not simply to fill every available square metre.

A detailed analysis starts with interval data, ideally across at least 12 months. This reveals when energy is used, when maximum demand occurs and how much solar generation can be consumed on site. It should be combined with an operational discussion: Will production expand? Is a new machine planned? Are shifts changing? Is electrification replacing gas or diesel equipment?

For the case study factory, the initial design deliberately leaves room for future expansion. If the business adds a second shift or electrifies a major process, it may be able to increase solar capacity later and improve the economics of a battery.

Where a battery may improve the outcome

A battery is not automatically the next step for every factory. In this example, solar alone produces a strong return because the site uses most generation during the day. Adding a battery could capture more surplus solar and discharge it during late-afternoon peaks, but the additional capital cost needs to be justified by the available tariff and demand savings.

Battery storage is most compelling where the site has sharp demand peaks, expensive evening consumption, frequent network constraints or a need for backup power for critical processes. It can also support greater control over energy use, particularly when paired with monitoring and intelligent load management.

The assessment should model the battery against real interval data, not a generic savings estimate. A battery sized for backup resilience may look different from one sized purely for bill reduction.

Protecting savings after installation

Solar savings are not a set-and-forget outcome. Panels need to remain clear of excessive dirt and debris, inverters need to be monitored, and faults should be identified before they reduce production for extended periods. Factory roofs also need safe access arrangements that allow servicing without disrupting operations.

Ongoing monitoring provides practical visibility. It can show whether generation is meeting expectations, identify unusual inverter performance and help facility managers understand how changing production schedules affect self-consumption. Periodic maintenance also protects warranty compliance and supports the long-term performance assumptions used in the original business case.

A capable provider should look beyond installation day. SAE Group can help industrial businesses assess their consumption profile, design an appropriately sized solar and battery solution, navigate available incentives and plan for monitoring and maintenance over the life of the system.

For factory decision-makers, the useful next step is not to ask how many panels fit on the roof. It is to understand when the site uses power, what that power costs at different times, and how a tailored solar system can turn a fixed operating expense into a more manageable long-term investment.