15kW Solar System

A 15kW solar system is typically installed on Homes with high energy consumption due to large families or extensive energy usage, such as with large air-conditioning systems or pool pumps, can benefit significantly from a 15kW solar system. These households typically have sufficient roof space to accommodate the necessary number of solar panels. 15kW solar systems are also popular on Businesses with moderate energy demands, such as small warehouses, restaurants, or retail shops. A 15kW solar system can significantly reduce electricity bills and operating costs for such establishments. At Outback Solar, we design custom solar solutions and we will advise you if you need or if your roof space can accommodate a 15kW Solar System.

How many panels are there in a 15kW Solar System?

A 15kW solar system typically consists of around 35 to 40 solar panels, depending on the wattage of each panel. In Australia currently an average size solar panel is between 390 Watts to 440 watts. For example, if I am using a 440W solar panel, then I will only require 35 solar panels to achieve a system size of 15000W or 15kW. However, variations may occur based on the solar panels efficiency, dimensions, available roof space, orientation, whether any shading issues are present, and local grid distributor regulations. In 2024, less roof space is required to install a 15kW solar system in comparison to lets say 10 or 15 years ago where the power of the panels were alot less. An Outback Solar Installer can come to your house and carry out an on-site measure and inspection to determine if you can fit a 15kW solar system. 

What is the output of a 15kW Solar System?

On average, a 15kW solar system can produce approximately 60-68 kWh kilowatt hours (kWh) of electricity per day in Australia, depending on factors such as sunlight exposure, weather conditions, and location of solar panels installed. Over the course of a year, this translates to roughly 21,900-24,800 kWh annually, a notch up from the popular 13kW solar system.

This level of energy production can power a variety of household appliances and devices, making it a versatile option for both large residential homes and businesses. A 15kW solar system can comfortably power most Australian household electrical and most Small Business operations. 

There is likely to be excess power generated by a 15kW solar system when installed on homes. This energy is typically exported back to the grid. In Australia, this is known feed-in tariffs and is done through your energy retailers approved net meter installed in your meter box. Outback solar always advises that you use the solar energy in your home or business rather than exporting back to the grid, as this will offset your electricity charges would cost you in upwards of 0.30 cents kWh.

Would type of inverter would best suit a 15kW Solar System?

A String Inverter is commonly used in residential and small business solar installations. It works by connecting multiple solar panels in series (a string), and then all strings are connected to the inverter. String inverters are a cost effective and relatively easy to install. However,  if your home or business is susceptible shade, then Outback Solar will advise you to install Micro-Inverters. In this setup if one panel in a string is shaded or underperforms, it wont affect the entire string’s output.

What’s the cost of a 15kW solar system?

The cost of a 15kW solar system can vary depending on several factors, including the choice of solar products used, installation complexity, location, and any additional equipment installed with your system. If you were to add battery storage, then this will vary cost even more. On average, in Australia, the cost of a 15kW solar system whether for residential or small business can be anywhere from $12,000 to $16,000. It will cost more if you were to use Micro-Inverters if you home or business is susceptible to shade on the roof. 

Australia offers various government incentives and rebates to encourage Australians to switch to solar power, such as the Small-scale Renewable Energy Scheme (SRES) and state based rebates, particularly on Batteries. These incentives can significantly reduce the upfront cost of your 15kW solar system.

You might need to upgrade your properties supply power to 3 Phase for such large system. This might further increase the cost but is definitely recommended as it will give you more flexibility in powering up various type of electrical tools or machinery if required.

Do I need to add a Battery to my 15kW Solar System?

To know whether you need a 15kW solar system with battery storage depends on your consumption pattern, grid network reliability, and your personal preferences. A 15kW solar system alone can significantly reduce your electricity bills by utilising solar energy during the day, instead of purchasing the energy from your Electricity Retailer. If you often consume electricity during the evening or night, then getting a 15kW solar system with battery storage could be a great idea. This system allows you to store your surplus solar energy generated throughout the day when its sunny and use it during evening hours after the sun sets.

Furthermore, adding a battery can provide additional benefits such as flexibility and access to backup power when or if a blackout happens in your area. If you experience blackouts frequently, then getting a battery installed with your 15kW Solar System is a no brainer. 

If you do not have access to the grid, then a 15kW off-grid solar system with battery would be the way to go. This will give you complete autonomy and allow you to become energy independent.

Have a chat with an Outback Solar consultant or specialist to help assess your energy consumption requirements and design a 15kW Solar System with battery storage customised to your energy needs.

What will a 15kW solar system save me?

To estimate how much a 15kW solar system will save you depends on many factors such as the install location of the system, your consumption of the solar generated, electricity charges, and your Feed in Tariff that you get when you export back to the grid. On average, a 15kW solar system in Australia can generate approximately 21,900-24,800 kilowatt hours (kWh) of energy output per year, which can put a big dent in your electricity bills.

At Outback Solar, we quite often get asked about payback periods and the return on investment when installing a 15kW solar system. This depends on the total out of pocket expense, how much of the power that is being generated is consumed, and how much of the power is getting export back to the grid. Lets go through a real life example.

Lets say the your out-of-pocket expense for purchasing and installing a 15kW solar system is $15,000 and your electricity rate is 0.33 cents.

Annual Energy Savings:

Your solar system generates an average of 24,800 kWh of electricity per year.
40% of the generated electricity is consumed onsite: 24,800 kWh year × 0.4 = 9,920 kWh year.
The remaining 60% is exported to the grid: 24,800 kWh year × 0.6 = 14,880 kWh year.
For onsite consumption, the annual energy savings would be: 9,920 kWh/year × $0.33 kWh = $3,274 year.
For exported electricity, the revenue generated would be: 14,880 kWh year × $0.08 kWh = $1.190 year.
Total annual energy savings: $3,274 year + $1,190 year = $4,464 year.

Payback Period:

Using the formula for payback period:

Payback Period = Out of Pocket Expense / Annual Energy Savings
Payback Period = $15,000 / $4,464 which is approximately 3.36 years

Your payback period can take longer If you were to add batteries with your 15kW solar system. Furthermore, Australian government STC incentives, or state based rebates and feed-in tariffs can make your savings even better. Over the lifespan of the system, typically 25 years plus, the cumulative savings from reduced electricity bills can be great.

Our Solar Calculator recommends the ideal solar system for your needs and estimates annual solar production and savings.

A useful resource for Australians interested in exploring energy savings options is the ‘Energy Made Easy’ website, an Australian government initiative designed to help consumers compare electricity offers from different electricity retailers. The website offers tools and information to help consumers understand their energy usage, compare energy plans, and find potential savings. Click Here or Visit www.energymadeeasy.gov.au

Or feel free to speak with an Outback Solar representative who can assess your electricity needs and provide you with a 15kW Solar System Estimate or Quote.

Get a Quote

Contact Outback Solar to get a quote for a 15kW Solar System.