Reviewed by Leigh McInerney
What is the daily output of a 20kW solar system?
A typical 20kW commercial solar system in Australia generates anywhere from 62 – 84kWh daily. This output varies daily depending on your location and the time of the year.
Different states across Australia receive varying power output from the 20kW solar system because of the varying sunlight intensities. Cities with higher sunlight intensities like Brisbane and Perth generate more power than Sidney and Melbourne.
Another key factor that affects your 20kW solar system output is the orientation and angle of solar panels. North-facing panels are the most efficient in Australia, while panels facing the East-West direction lose efficiency by nearly 20%.
Here’s a rough estimate of the daily output from a 20kW commercial solar system in different cities across the country.
| City | Solar Output |
|---|---|
| Sydney | 72kWh |
| Perth | 84kWh |
| Canberra | 77kWh |
| Melbourne | 67kWh |
| Hobart | 62kWh |
| Brisbane | 80kWh |
| Adelaide | 77kWh |
How many panels will I need for 20KW?
Around 68 solar panels. The 20kW commercial solar panel is quite big compared to most residential solar panels. It, therefore, uses a lot more panels. The actual number you might need for your system will depend on the size (rating) of panels you choose.
The formula for this total simply requires you to divide your system’s total size (20,000W) by the size of solar panels you choose.
If you choose solar panels with higher energy ratings, e.g., 300W, 330W or 350W you’ll need only 67, 60, and 58 panels respectively. However, with lower-rated panels, e.g., 250W, 260W, 275W, you’ll need 80, 77 and 73 solar panels respectively.
How much roof space is needed for a 20kW solar system?
Assuming you’re using the average 1.7m x 1m solar panels, you’ll need anywhere from 98.6 m2 to 136 m2 of roof space. This is assuming you use the 58 – 80 solar panels from the 250 – 350W.
Your roof shape, condition and orientation may also demand more roof space than expected. Get an expert installer to assess how much space you’ll need.
You might also have to remove some of the things mounted on your roof to create more space. Homes with flat roofs may also need more space as they have to make room for tilting frames.
All things considered; you may end up requiring around 150m2 of roof space.
20kW Solar System Cost
The 20kW commercial solar system is ideal for various mid-sized commercial enterprises and manufacturing facilities.
You can expect to pay around $18,771 for a 20kW system installed. Prices can vary wildly depending on the quality of panels you install and the company that quotes the job.
The above price is after you have received your government rebate ($6,464 for 20kW systems) and does not include the price for battery backup.
How long until a 20kW solar system pays for itself?
Around 3 – 5 years. One of the main benefits of investing in commercial solar systems is their quick payback period. Your 20kW commercial solar system usually offsets its initial investment costs by the fourth year. This gives you enough time to enjoy 20 – 25 years of savings from ‘free energy’.
However, several factors affect how fast your 20kW commercial solar system can pay for itself. These include your location and your energy consumption habits.
As mentioned earlier, the price of 20kW solar systems varies between states because of the different rebates offered.
Therefore, in states where the cost is higher, solar systems tend to have a longer payback period than in states where panels are cheaper.
Businesses that consume more energy during the day also record faster payback periods. You should, therefore, consume more of your generated power to improve the system’s ROI.
Battery storage for 20kW solar system
When looking to maximize on your 20kW commercial solar system, investing in solar battery storage is a good option. Solar batteries ensure that your business can consume nearly all of its generated energy, thus increasing your savings.
Battery storage is also crucial during power blackouts and cloudy or rainy days, as it ensures your business operation doesn’t stop.
What Battery size do you need?
If you’re going to invest in solar batteries, you need to know how to size one correctly to suit your solar system.
The good news is most commercial places of business use the bulk of their energy while the sun is shining. This is different for residents who need to store most of their power for the night.
A 20kW system produces 75kW of power during the day, you might need to store 30-40 % of that for use before the sun comes up and after the sun goes down.
You’ll need to store 25-30kW of power which is 2 x 14kW Tesla Powerwalls. Each costs $12,500.
How much money can I save with a 20kW system?
A 20kW solar system save you up to $10,000 every year. Since it generates so much power daily, you can save money by consuming the generated power, storing it for later use, and even the feed-in tariff.
In general, how much you save with commercial solar systems depends on your energy consumption and the current cost of electricity.
The more power you consume from your solar systems, the more money you save. This also includes the incentives you receive from sending your excess power to the grid.
Additionally, the rising electricity costs in the country play a key role in increasing your savings. (We count your savings as the total amount of grid power that you avoid using by going solar).
How do I calculate my solar savings?
Here’s an easy way to help you calculate how much savings you can have annually.
We’ll take a business in Brisbane which consumes about 80% of its power during the day. The electricity cost in Brisbane is around 28c/kWh, and the average feed-in rate is about 10c/kWh.
With the average daily output for a 20kW commercial solar system in Brisbane being 80kWh, this business consumes 64kWh daily. This converts to around 23,360kWh annually.
In savings, this becomes: 23,360 x 0.28 = $6,540 annually.
The surplus generated power is 16kWh daily or 5,840kWh annually. If this is sent back to the grid, the business also receives: 5,840 x 0.10 = $584 in feed-in tariff income.
Your total saving for the year, therefore, becomes: $6,540 + $584 = $7,124.
With such savings, you’ll considerably cut down your power costs and reliance on power from the grid.
FAQs
How does solar power reduce your electricity bill?
There are three main ways in which solar panels can reduce your power bills. The main way is through reducing your reliance on power from the national grid. With businesses spending nearly 70% of their power during the day, their monthly bills will be drastically low.
Solar power also saves you money through the feed-in tariff scheme and the federal tax credits.
Do I need to pay tax on the income from a feed-in tariff?
Usually, no. The income from feed-in tariffs, based on residential solar systems is not taxable in Australia. However, feed-in tariffs income may be taxable if the solar system is on a commercial building.
So, if you use your building to make a profit of any kind, then your feed-in income is taxable. Nevertheless, this law is still quite vague and so, make sure you consult an expert before ruling out the taxes.
