50kW Commercial Solar System Cost

Updated: April 27, 2021

The 50kW solar system is a popular size for commercial applications as it covers a large percentage of small to medium sized power needs.

On average, a 50kW solar system costs around $48,750, including government rebates and other incentives. The true range is between $45,500 – $52,000 depending on your location and the brand of solar panels and inverter you go with.

The installation cost is usually included in this price range, as it can only be done by a certified installer.

Average cost of 5kW solar system
StateSystem SizeZoneZone ratingRebate
New South Wales50kW31.382$25,912.50
Queensland50kW11.622$30,412.50

South Australia
50kW31.382$25,912.50
Victoria50kW41.185$22,218.75
Western Australia50kW31.382$25,912.50
ACT50kW31.382$25,912.50
Northern Territory50kW1 - 21.536$28,800
Tasmania50kW41.185$22,218.75

The government’s solar rebate initiative has been crucial in helping Australian businesses afford solar systems. The program, under the Small-Scale Renewable Energy Scheme, provides incentives for solar systems under 100kW.

The rebates come in the form of Small-scale technology certificates, STCs, which are tradable certificates you can exchange for discounts on your solar systems.

The rebate amount will also vary depending on your location by it ranges between $ 22,218 and $30,412.

States with higher sunlight intensities got a higher postal rating than those with lower intensities. As such, the rebate amount you receive for your 50kW solar system in Canberra won’t be the same you’ll receive in Melbourne.

Here’s how you can calculate the number of STCs you can receive:

Formula: kW solar panels x 10-year deeming period x Zone rating X Spot STC price. (The deeming period is the time left to 2030 – when the program will be completely phased out, and the spot check price used is $37.50 (average of last month)).

Note: Different states also offer state-level rebate programs that are independent of the federal government rebate. Residents in Victoria, Western Australia, South Australia, NSW, and Tasmania can complement the federal rebates to the state rebates to significantly reduce the cost of solar systems.

The state governments in Tasmania and Queensland are also offering solar grants which can drastically cut down solar costs.

What's the Feed-in tariff for a 50kW solar system

Once you have your 50kW solar system installed, you can quickly reduce its payback period through the feed-in tariff program.

Under this program, select energy companies around the country pay solar owners to sell back the excess energy they produce from your solar system. The program favors residential and SME solar installations.

For your 50kW solar system, you’ll first have to confirm if your energy company allows that size for the program. Keep in mind; most companies have an upper limit for the size of the solar system they can accommodate for the program.

In terms of the feed-in rate you’ll receive for your power, different companies will offer you different rates. These figures will vary depending on your state.

To better understand the rates you can expect, here are the top 3 companies with the best feed-in rates.

Company1st Company (Average Rate) – c/kWh2nd Company (Average Rate) – c/kWh3rd Company (Average Rate) – c/kWh
NSWOrigin Energy – 16.5AGL – 15.55Mojo Power – 15.0
VICOrigin – 17.0AGL – 15.65DC Power Co – 15.0
QLDEnergy Australia – 16.15AGL – 15.3DC Power Co – 15.0
SAAGL – 18.15Origin Energy – 16.5Power Direct – 16.3
ACTOrigin Energy – 14.0Energy local – 12.5Energy Australia – 12.5
WAHorizon – 30.0Synergy – 7.2N/A
NTJacana Energy – 23.6Power water corporation – 19.23N/A

Keep in mind; The income you receive from your feed-in tariffs is usually taxable for commercial buildings. Therefore, it would be wise to confirm whether or not you’ll be taxed before enrolling in the program.

commercial-solar-feed-in-tariff-how-it-works

What's the payback period on 50kW solar?

Most 50kW solar systems in Australia have an average payback period of 4 years. However, depending on your location and energy consumption patterns, the system may payback in as short as 3 years, or extend to around 5 years.

The more energy you consume from your 50kW solar system, the faster it will pay itself back.

Similarly, the more sunlight your panels receive, the more power it can generate and hence, the faster the system can pay itself. To calculate your average payback period, simply divide the total cost of the system by your annual savings.

In the cost, don’t forget to include the maintenance and repair costs.

And since the price of solar systems varies by state, your payback period will depend on your state.

For your annual savings, the price of electricity determines how much you can save. The higher the electricity costs, the more you save and hence the faster the payback period.

payback period on 50kW solar

Number of panels needed for 50KW

The number of solar panels you’ll need for your solar system will depend on the size (Wattage) of solar panels you choose. The higher the panel wattage, the fewer the panels you’ll need.

Here’s a rough estimate of the number of panels you’ll need, using the most popular 260 – 330W solar panel.

Formula:

No. of panels = Size of the system (kW)

Output of panel   

If you’re using 260W solar panels, you’ll require: 50,000/260= 193 panels.

If you’re using 275W solar panels, you’ll require: 50,000/275 = 182 panels.

If you’re using 300W solar panels, you’ll require: 50,000/300 =167 panels.

If you’re using 330W solar panels, you’ll require: 50,000/330 =152 panels.

number-of-panels-for-50-kw-solar-system

Roof space is needed for 50kW solar

The standard size of solar panels in the Australian market is 1.7m x 1m. Therefore, if you’re using the 260W – 330W solar panels, you’ll need between 258.4m2 – 328.1m2.

However, other factors such as your roof’s shape, its orientation, and the equipment mounted may demand slightly more space. For the best calculations, contact a solar installer in your area to give you an estimate of the total roof space you’ll need.

Battery size for 50kW’s

With the 50kW solar system generating so much energy, investing in solar battery storage can help eliminate your energy bills and increase the ROI of your solar system.

The best thing about solar batteries for your 50kW solar system is that you don’t need a massive battery. In fact, the solar battery for your commercial building might be smaller than that required by a residential system.

This is because commercial systems use 70 – 80% of their energy during the day, and the remaining 30% goes to the battery. For residential systems, the battery needs to be huge since most homes use 70% of their energy at night.

With this in mind, you’ll only need a 40 – 60kWh solar battery for your 50kW solar system. You can opt for a slightly smaller or larger battery but ensure you don’t oversize.

If you’re planning to go completely off-grid, you will also need a relatively bigger solar battery to ensure your business operations don’t halt during the nights.

tesla-power-wall-stack-commercial-system

50kW solar inverter for commercial solar

For most solar systems, the size of the inverters you need should match the size of your solar system. Therefore, for a 50kW solar system, you need a 50kW or 50,000W inverter or 5 single-phase inverters rated 10kW each.

However, the size of inverters you’ll need may vary depending on your location. In areas that receive high solar intensities, your inverter should be as close to 50kW as possible to keep up with the high power generated.

But if you’re in an area with low sunlight intensities, you can choose a slightly undersized inverter. This is because low sun intensities result in lower overall output for your system.

For better efficiency, you can also opt for microinverters. Although they are more expensive, the microinverter on each panel ensures maximum output for your solar system.

Some of the best inverters you’ll find in the Australian market today are from SMA, Fronius, SolarEdge, Enphase, Sungrow, Delta, Goodwe, ABB, and Huawei.

Nevertheless, the best way to accurately size an inverter for your 50kW solar system is by consulting an accredited solar installer. They have the expertise and experience to recommend the best inverter for you.

inverter

Daily output of a 50kW solar panel system

A 50kW solar system generates an average of 200kWh daily, but this output varies depending on the location and time of the year. Generally, solar outputs are highest during the summers since the days are longer, and shortest during winter.

Different states in Australia also receive different solar power outputs from the same 50kW solar system. This is because different parts of Australia receive varying sunlight intensities.

States that receive high solar intensities like Western Australia and Queensland generate outputs between 200 – 220kWh daily and up to 275kWh during summers.

Low-intensity states like South Australia and Tasmania generate lows of between 180-200kWh, and up to 150kWh during winter.

The orientation and tilt angles of your solar panels also affect how much output you can get from your solar system. North facing panels, tilted at around 30o have proven to yield the highest output in Australia.

Monthly output of a 50kW solar system

Monthly, a 50kW solar system generates an average of 6,000kWh. Here’s a table showing the average output in each city. These figures consider the cloudy and rainy days of the month.

CityMonthly output
Adelaide6,388kWh
Sidney5,931kWh
Melbourne5,475kWh
Canberra6,540kWh
Hobart5,323kWh
Brisbane6,388kWh
Perth6,692kWh
Darwin6,692kWh

How much money will I save with a 50kW system?

With solar power, the more energy you consume, the higher your savings will be. And since most businesses spend nearly 70% of their generated energy during the day, your savings from a 50kW solar system will be really high.

Here’s how you can calculate the savings you’ll expect from your system. For this example, we’ll assume:

  • Your business is in Melbourne (System output 200kWh)
  • The cost of electricity is 30c/kWh
  • Your business consumes 70% of the generated power and exports the rest.
  • Your feed-in rate 9c/kWh

Therefore, your system will be generating: 200 x 365 = 73000kWh annually. If you consume 70% of this output, you’ll consume around; 730000 x 0.7 = 51100kWh and export 21,900kWh to the grid.

In terms of savings, this becomes: 51,100 x 0.30 = $15,330 in consumption savings and around; 21,900 x 0.09 = $1,971 in feed-in tariff income.

In total, your annual savings will amount to: $15,330 + $1,971 = $17,301.

Note: The feed-in rates may be a bit lower since most of the energy will be sent to the grid during off-peak hours.

FAQs

About 4,000 square feet. The complete 50kW solar system kit is quite large, taking up to 152 north-facing solar panels and generating around 6,000 kWh monthly. This makes it perfect for small and medium-sized commercial buildings which receive annual power bills of up to $15,000+. 

No! Most solar panels last between 25 – 30 years before they may need to be replaced. After the 20th year, the efficiency of most solar panels drops to less than 80%. This is why most manufacturers offer solar panel warranties of up to 25 years.

Between 10 and 15 years. Unlike solar panels, solar batteries are yet to last past the 15-year mark. Depending on the type of battery, some batteries only last for 5 years. You will have to change your battery at least once during the lifespan of your solar system.

10 – 20 years. Being the only moving part in your solar system, the inverter is mainly affected by heat and humidity, making it hard for it to last for two decades. You’ll need to conduct regular maintenance and repairs to extend its lifespan past the 10-year mark.

Ben McInerney head shotAuthor: Ben McInerney is a renewable energy enthusiast with the goal of helping more Australians understand solar systems to make the best choice before they purchase. Having an accredited solar installer in the family helps give Ben access to the correct information, which allows him to break it down and make it easily understandable to the average homeowner.