Reviewed by Bidhan Bhuson Roy
Daily output of a 100kW solar panel system
The 100kW commercial solar system generates an average of 400kWh daily. The real range is between 360kWh and 440kWh depending on your location.
Solar systems in cities like Brisbane, Perth, Darwin, and Canberra generally generate more power compared to those in Sydney and Melbourne. This is because these areas receive higher solar intensities. Â
Other factors that affect the output of solar panels include their tilt angle, orientation, and time of year.
Solar panels in the southern hemisphere produce more power when facing the North. Panels tilted at least 30o also tend to produce more power than panels on flat roofs.
| City | Monthly output |
|---|---|
| Adelaide | 11,550kWh |
| Sidney | 10,800kWh |
| Melbourne | 10,200kWh |
| Canberra | 11,550kWh |
| Hobart | 9,900kWh |
| Brisbane | 12,000kWh |
| Perth | 12,600kWh |
| Darwin | 13,200kWh |
Number of panels needed for 100KW
Most 100kW commercial solar systems need between 330 – 400 solar panels. The actual number depends on the power ratings of the solar panels you’re using. For instance,
If you’re using 250W solar panels, you’ll require: 100,000 / 250W = 400 panels.
If you’re using 275W solar panels, you’ll require: 100,000 / 275W = 364 panels.
If you’re using 300W solar panels, you’ll require: 100,000 / 300W = 334 panels.Â
The lower the power rating of the solar panels you use, the more the panels you’ll need. For commercial businesses with limited roof space, panels rated 330W and 350W can mean you only need 304 and 286 panels respectively!
Roof space is needed for 100kW solar
The total roof space you’ll need will depend on the size and number of solar panels you use. Most manufacturers use a standard size,1.7m x 1m, for their panels, meaning each panel occupies 1.7m2 on your roof.
Therefore, for 350 – 400 solar panels, you’ll need approximately 595m2 – 680m2.
You’ll also need to account for your roof’s shape and orientation and any components mounted on the roof.
A good practice would be to consult with an expert to help with the sizing.
100kW Solar System Cost
A 100kW solar system in Australia costs $86,200 – $95,000, depending on panel quality, inverter configuration, installation conditions and the level of monitoring or protection hardware required.
These prices include the federal STC rebate, which reduces the upfront cost for eligible commercial systems. Most businesses opt for Tier-1 panels and high-efficiency inverters for reliability, which generally places final install costs toward the upper end of the range.
What's the payback period on 100kW solar?
Usually, anywhere between 3 and 5 years. There are numerous factors that determine how fast your 100kW commercial solar system can pay for itself. The most important include your energy consumption and your location.
Your location determines how much sunlight your solar system receives. This, in turn, determines how much rebate you receive for your 100kW solar system, and hence, its overall price.
Keep in mind; Calculating your payback means dividing the total cost of your solar system by how much you can save annually. The more expensive the system is, the longer it might take to pay back.
Your energy consumption is also crucial in determining how fast the system can pay itself. The more energy you consume during the day, the faster the solar system pays for itself.
Thankfully, most businesses spend most of their power during the daytime. This results in immense savings in power costs and faster payback.       Â
How much money will I save with a 100kW system?
With such a high daily power output, you can save anywhere from $20,000 to $50,000+ every year. It will all depend on how much power your business consumes daily.
Generally, businesses that consume more of their generated energy have reported higher savings. You’ll also earn more savings depending on the cost of electricity in your area.
Higher electricity costs mean you’re not spending a lot of money on electricity from the grid.
Here’s how you can calculate your savings with a 100kW solar system.
Assuming that you’re living in Sydney where electricity costs 32c/kWh, with a monthly solar power output of 10,800kWh. If you consume 70% of your generated power, you’ll be consuming 7,560kWh.
In savings, this translates to around $2,419.20. Annually, this is around $29,030.40, excluding any income from the feed-in tariffs. When you include feed-in tariffs, you easily save more than $30,000 each year.
This gives your solar system slightly over 3 years in its payback period.
If you install a solar battery, you further increase your savings since your reliance on the grid electricity will be lower.
Battery size for 100kW’s
Once your 100kW commercial solar system is running, installing a solar battery can drastically improve the system’s ROI. The battery allows you to store the free solar energy for later use instead of relying on power from the grid and the feed-in tariffs.
However, most businesses fear going for solar batteries because of their high costs. What they don’t know is that commercial solar systems don’t require massive batteries. The solar battery size for your solar system might be similar to that of a residential system or even smaller.
This is because commercial businesses utilize around 70% of their power during the day, leaving only 30% of the generated power for the battery or sending it back to the grid.
Residential systems, on the other hand, need large batteries because they spend around 70% of their power at night.
Therefore, with most businesses consuming an average of 350kWh, your 100kW solar system only requires a 105kWh battery.
However, if you’re going completely off-grid, you might need a bigger solar battery that meets your daily energy consumption demands.
Are the solar batteries worth it?
Well, it depends. Different commercial businesses have different energy needs. For a business that requires constant power for its operations, solar batteries might be worth it. The batteries will provide a good backup.
However, for regular businesses working during the day, the high cost of solar batteries might not be worth it. Adding a battery increases not only the cost but also the overall payback period of your solar system.
It would actually be cheaper to channel the surplus power back to the grid or invest that money in a bigger solar system.
FAQs
Around 700 square meters. The 100kW commercial solar system is one of the biggest systems in the Australian market today. It incorporates around 400 solar panels, about 4 inverters and generates more than 12,000kWh monthly.
Yes! Investing in solar panels for businesses can really help cut down their energy costs and boost their profits. Going solar is particularly beneficial for businesses in areas with high electricity costs and high sunlight intensities.
There are also other benefits of solar, like helping save the environment and improving your property’s market value.
No! Solar panels will not destroy your roof unless the roof is in a poor condition, or when installed by an inexperienced installer. Always go for an accredited solar installer when installing your solar panels.
Yes! Both the federal government and some state governments offer generous incentive programs to bring down solar costs. These rebates can cover up to 50% of your total solar cost. Read here to find out more about the program and whether you qualify for it.
