100kW Solar System Facts and Costs – Australia - 2021

As a business leader, you probably have received solar quotes or are considering seeking one. Yet, you have concerns such as:

* What is the best price for a quality 100 kW system?

* Is 100kW really the best size for your site? 

* You are really busy with your business.

* Not sure how much solar/ batteries can save you?

* Are solar rebates really gone? How much government incentive can you get now?

* So many solar companies come and go; Which one can you trust?

* Are quotes with different designs, brands and prices confusing you?

Regardless, high and uncertain energy costs are hurting you. And doing nothing is the costliest thing you can do. How come? Just see your last few electricity bills and you’ll know what we mean.

A very common and attractive size of commercial solar is 100 kW (kWp). This article will help you be crystal-clear and knowledgeable on commercial 100 kW system facts and costs.

The benefits of a 100 kW solar system

The benefits of a 100 kW system include:

1. 100 kW, or otherwise commonly referred to as 99 kW solar system allows you to access the maximum amount of STC incentive/ upfront discount
2. It comes with an excellent economy of scale pushing the $/ Watt cost down.
3. It’s not big enough to invite the electricity distributors to apply a more complicated or costly connection approval process.
4. Most commercial sites can get a significant amount of savings unless the sites consume very large amounts of energy. 
5. Terrific payback and RoI (Return-on-Investment), especially with the recent Instant Asset Write-Off Incentive

100kW solar system cost - estimates by states

Scroll to the bottom of the page to use our costing tool.

How much power does a 100kW solar PV system generate?

The below table is laid out based on the metro area that the installation is situated in or close to.

The production estimates are for the first year and subject to site-specific design and configurations

Data Source: PV-GC spreadsheet based on the CEC GC Design Guidelines

The production estimates are for the first year and subject to site-specific design and configurations.

100kW solar system payback and ROI

With various government incentives including the Instant Asset Write-Off, the payback is the best it has ever been. 

In many cases, the payback is between 1.9 years and 4 years. 

The ROI (Return on Investment) is mostly between 25%-53%. 

Where else would a business investment get a return like this with low, predictable risk?

The savings from 100kW solar system (panels)

Data Source: PV-GC spreadsheet based on the CEC GC Design Guidelines

Additional savings from demand reduction, if applicable, would be on top of the figures above.

The production estimates are for the first year and subject to site-specific design and configurations.

Click 'Ask A Question' at the bottom of the page if you are ready to get quotes. If not, then read on to learn more.

We’ve invested hundreds of hours on extensive data to come up with the instant price estimating tool below. But, don’t use it until you understand how commercial solar quotes work as outlined below.

Our engineer associates have drawn from about 15 years of experience to produce ‘The Commercial Solar Guide’. It’s conservatively worth $1500 as it can help you avoid thousands of dollars of pitfalls. We want you to see the benefits of using our hub by giving you a free copy - subscribe at the bottom of the page.

Major factors affecting 100kW commercial solar costs

The cost of installing a commercial solar system varies widely. This is because it’s affected by a range of factors, such as:

* The equipment you use: Type, size, brand and the configuration of panels and inverters affect the price – premium PV panels can increase the total cost to about 20% more. While premium equipment like Sunpower panel is not for everyone, we would only recommend reputable tier-1 equipment

* The solar retailer or installer: Some installers are willing to drop their labour costs to rock bottom. But, in almost every case, this results in a rushed job, compromise on the workmanship, and sub-standard or non-existent service. If it’s too cheap, then it often ends up being an expensive painful problem down the track.

* Your warranties: guarantees and any after-sales service agreements will determine the terms which repairs or exchanges will be made. It’s recommended that you seek tier-1 panels with a 15-year product warranty and quality inverters with a 10-year warranty.

* Available government incentives: various rebates and other incentives are available for commercial solar – find out which ones are included in the quote and how they are calculated

* Optimisers or microinverters – only go for these if there is a technical reason for it, such as partial shading

* Type of mounting kit and other balance of system components (isolators, circuit breakers etc)

* Height and accessibility of roof - Do we need an elevated work platform, scaffold or crane?

* The type of roof: Trimdek, KlipLok or tiles are some common types; KlipLok mounting cost a bit more than Trimdek/ Corrugated roofs.

* The complexity of solar panel layout – for example: if multiple roofs are involved, the number of split arrays, obstacles and shading on the roof and if tilting is requested

* The capacity and age of the switchboard - Does it need upgrading?

* Location of the inverters and lengths of the cable run

* Your location - The rebates for small-scale technology certificates (STC) vary based on the location of your commercial solar system.

* Are grid protection units, export limits or additional engineering required by the electricity distributor?

As you can see, there are important details that must not be missed if you are to make the best decision. 

The size of your commercial solar system

If you use the commercial solar pricing tool below, you’ll come across some general patterns. For example, the larger the kilowatt (kW) the lower the cost per watt ($/Watt). This indicates that the cost-efficiency improves with more kWs. A few reasons contribute to this, but the main one is economies of scale.

However, there are exceptions to this such as above 100 kW and below 140kW

As soon as it exceeds 100kW, STC incentives don’t apply anymore. Instead, the ongoing large-scale generation certificates (LGC) incentive kicks in and this can lead to another comprehensive topic. In short, this incentive gets realised once the generation data gets approved by the authority and the LGC certificates get generated. The claim is typically done periodically such as quarterly or yearly. Currently, the LGC values and projection are not high, so some businesses prefer to get the upfront rebate to bring the $/Watt down. They do this by keeping to about 99kW, even if the roof space or consumption warrants between 100kW and 140kW.

Again, this is not definite because it depends on your business objectives. It would still make sense for sites with higher consumption to go with an LGC system above 140kW because the economy of scale is excellent for LGC systems. Also, large systems offset more grid electricity.

Common pitfalls in buying 100 kW commercial solar system

Commercial solar systems can go wrong in a number of ways depending on what business decisions are made. The main ones we commonly see are:

a. Decisions are based only on price

If the commercial solar quote is too cheap then shortcuts could compromise on quality, service, and safety. Without the right project and technical knowledge, these will not be discovered until it’s too late.

b. When project drivers are unclear

What is the motivation behind adopting a commercial solar system? Reasons include reducing energy cost, hedging energy price, maximising rebate, optimising payback and ROI, and adopting the Energy-as-a-Service model.

c. Confusion between exclusions and inclusions

Not understanding these two factors can surprise you with cost variations later.

d. When there’s no due diligence on the solar retailer/ installer

Most solar retail companies come from residential sectors, which means they often lack enough project and engineering experience to deal with commercial projects. Only a small percentage of solar retailers last more than a few years, so due diligence is necessary.

e. Giving in to sales cowboys

Many solar companies have stock they need to move and will sell you suboptimal solutions or old technologies. It’s worthwhile taking the time to select the best equipment for your specific site.

How to avoid these common pitfalls?

Several points discussed on this page can equip you to be savvier. You can overcome these issues by engaging independent engineers – such as ones endorsed by Solarpedia – who specialise in commercial solar. This will help you reduce the risk of your commercial solar system by helping you make informed decisions.

How to obtain the best 100 kW solar system quote

Deciding to purchase a solar is no ordinary task because it’s a technical system that ideally should last up to 25 years. To tackle this challenge, it’s crucial to have an engineering and project mindset from the beginning. Some important things to consider:

1. The project drivers and objectives
2. Understanding of your tariff structure and consumption profile
3. Due diligence on the solar companies
4. Understanding if the payback, ROI and saving quoted by the solar company are accurate
5. A site assessment by the quoting solar company
6. Use a project brief or specifications so solar companies can quote suitable solutions
7. Compare 2-3 quotes from reputable companies carefully because there will be variations in prices, equipment brands, design, and sizing. 
8. Use a benchmarking and comparison system to compare apples with apples

In our experience, even an engineer who doesn’t specialise in solar would need more than 40 hours to research and make an informed decision for a small 30kW project. Bigger projects such as a 100kW system would warrant more hours. If you or your team are busy and want to make it easy and low-risk, then consider having an independent technical advisor doing this work for you.

100kW solar system quote inclusion, exclusion and scope

A common problem when sourcing commercial solar quotes is that different solar companies use various formats for their proposals and quotes. This can be frustrating as it becomes difficult to pinpoint the total cost of the project. As a rule of thumb, look for the minimum inclusions below:

* Solar panels
* Inverter(s)
* Mounting
* Full installation by Clean Energy Council accredited electricians
* System design and supply
* Freight to site
* Cabling, conduit, and safety labelling
* DC & AC circuit breakers and enclosures
* Solar electrical distribution board(s) – for larger systems
* The balance of the system, including other consumables
* Appropriate labelling and connection to the existing electrical switchboard
* Project management
* Grid connection and meter reconfiguration
* Documentation and manuals
* Final commissioning and handover on-site.

Some solar retailers exclude these points, but you should also account for:
* Edge protection
* Grid connection application and electricity distributor’s fee
* Network protection unit – for larger than 30kW systems
* Upgrades to existing electrical switchboard(s) (if required)
* Network augmentation (if required)
* Permanent roof access ladders and walkways (if required)
* Underground electrical works (if required)

Removing payback concerns with smart funding

Directors or managers often argue that the high cost or payback time is too much to make the switch worth it. That is an understandable concern. What if you could get solar photovoltaic (PV) cells that pay themselves off – hence no capital outlay? Payback would no longer be a concern.

How it works

Fund your commercial solar system by using alternative $0 solar scheme options such as a chattel mortgage, rental, PPA (Power Purchase Agreement), or the Environmental Upgrade Agreement (EUA). The specialist financiers provide the funds to fully supply and install the system, allowing businesses to continue operating whilst conserving money and benefitting from solar.

A breakdown of a typical 100 kW solar PV system quote (Melbourne or Geelong)

Below is a breakdown of a quality 100kW system in Melbourne’s metropolitan area as of January 2021. While it’s not specifically associated with a particular project, it’s in the ballpark when it comes to a quality solution installed by a reputable installer. Precise costing is subject to site conditions as every site requires a bespoke solution.

Commercial solar price estimator

Use the tool below to instantly estimate commercial solar prices across different states.
NOTE: This is an average estimate. If you use the approach suggested on this page it’s common to get a few per cent of savings!!

About The Writers and How They Can Help

Some key contributors to Solarpedia, including this article are engineers from Free Engineer. They make commercial solar simple and help business leaders get the best quote, with a 100% money-back guarantee!

Imagine if you have independent solar engineers who do it all from start to finish while you can focus your time and energy on your business.
* They analyse (technical and economics of solar)
* They design
* They project manage
* They help you find trustworthy supplier and installer
* They verify your savings

Yet you have the freedom – to choose the design and the equipment you like best, not the stocks that salespeople need to get rid of.

Here’s how they helped a few clients:

1. Jamie Meizer – engineer and business owner (30 kW solar)

2. Mr. Li, The CEO of Sealane Foodservice (376 kW solar) wrote:

Going solar was not easy because it could be a big, long-term investment and there are so many solar companies pushing different products in the market. Each solar company claimed they were the best while offering different sizes and solutions which led to confusion.  Free Engineer (FE) made it easy and help us with professional trusted advice to get a deal that is about $100,000 better than the initial proposal. 

The installer recommended was very professional and took care of every problem that arose. Free Engineer returned to the site after completion and provided before and after bill analysis confirming dollar saving of almost 60% for February 2019 period compared to February 2018 period. We'd highly recommend Free Engineer.

3. Softmed, Australia’s largest PPE manufacturer

Free Engineer saved them more than $30,000 through a smarter procurement strategy and helped them overcome structural engineering issues. Here’s the video of the install:

Get 100kW solar system quote 

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Final notes:

• The prices mentioned on this page don’t incorporate meter installation fees or additional costs, such as ground-mounting or grid network studies for larger systems.
• Please consult your accountant if Instant Asset Write-Off applies to your organisation.
• This estimate is usually within +/- 5% and subject to site-specific conditions.
• Please submit the form below if you want one of Solarpedia's approved engineers to:
• fine-tune this estimate and obtain the latest quotes
• estimate a more than 1MW (MegaWatt) system
• estimate ground-mount systems

• Source: https://www.cleanenergycouncil.org.au/consumers/buying-solar/costs-and-savings