8kW Solar System – Costs, Savings, Payback

An 8kW solar system is perfect for large households with higher than average energy expenses. It’s also ideal for minor commercial use due to its superior power output. Is this large system a match for your home?

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An 8kW solar system is perfect for large households with higher than average energy expenses. It’s also ideal for minor commercial use due to its superior power output.

Solar systems are not only beneficial to our environment, they also offer homeowners numerous advantages. Long-term savings, decreased energy expenses, and energy independence lures many individuals into installing a solar system for their homes.

But solar systems come in various sizes and choosing the right one can be difficult. Power output, costs, payback period, and other technicalities need to be accounted for.

An 8 kW solar system is an ideal choice for most homes. Its price-to-capacity ratio is the number one reason for its popularity.

Is an 8kW Solar System Suitable for My Home?

The solar industry offers an array of solar systems, with each differing in the amount of power they generate. An 8kW solar system is the best choice for sizable households or small-scale businesses.

If you’re considering a solar system, think about the size of your household. What are your average energy expenses per month? A large number of electrical appliances in use may require additional battery storage.

8kW is an extensive solar system with enough power to suit large households’ needs. Suppose you run several electrical appliances in your home, like a reverse cycle air conditioning system, washers, dryers, etc. In that case, you’re more likely to benefit from an 8kW solar system.

And if your electricity bills usually surpass $500 every four months, an 8kW solar installation will help you streamline your electricity budget.

How Many Solar Panels are in an 8kW System?

To achieve 8kW of solar system output requires several solar panels. Usually, an 8kW solar system comprises 21 to 28 panels, with the number decreasing as you raise the panels’ efficiency.

Solar systems do a fantastic job at keeping your electricity budget in check. Due to the considerable solar system output of an 8kW solar, it’s understandable that it requires a higher amount of solar panels. 

The number of panels depends on their Watt solar output. Below are several solar panel combinations:

Solar panel’s capacityNumber of solar panels needed to give 8kW energy output
24033
25032
26031
30027
33025

It’s worth mentioning that costs are considerable due to the excess solar power and a large number of solar panels. Hence, it’s better to buy top-notch solar panels with quality components to obtain the best use of your investment.

Do I Have Enough Roof Space for an 8kW Solar System?

To install 21 to 28 solar panels for an 8kW solar system, you’ll need approximately 34 – 45 metres of roof space.

A consideration among solar installers when choosing an 8kW solar is whether you have the space to facilitate a large set of solar panels. You can always compromise with smaller roof space for panels with higher wattage.

On average, solar panels are 1.7m in length and 1m in width. So if you install 32 solar panels of 250 W capacity, you’ll need approximately 13.6 square metres of available space on your roof.

The area on your rooftop should also be compatible, with nothing to hinder sunlight or the solar installation structure. This includes complex roof faces, toxic materials, and intense shading.

How Much Does an 8 kW Solar System Cost?

On average, the cost of an 8kW solar system ranges from $6k to $12k, with prices adjusting significantly with the quality of the system and installation.

The cost of an 8 kW solar system in Australia depends on:

  • the number of solar panels,
  • the solar panel capacity,
  • the solar panel quality, and
  • the inclusion or absence of a battery.

The clean energy council does not give a price for an 8kW system. But they suggest a 10kw system is in the range of $7600 to $14100.

How Much Will an 8 kW Solar System Save You?

Based on estimates, an 8kW solar system is likely to save you $3,500 on your annual electricity bill. Your potential savings start on the next day of your solar installation.

There’s more than one method for saving with a solar system. First, you can save by producing your own electricity and paying less for grid power. Second, you can sell excess solar energy you generate to the system to reduce your net bills. 

You can save somewhere around $3,500 from your annual electricity expenses. That amounts to $850 on a quarterly billing cycle and $30 to $35 per month. However, your potential savings are heavily influenced by:

  • your energy consumption,
  • the amount of energy you sell to the grid,
  • the feed-in tariffs your electricity retailers pay, and
  • the amount of self-produced energy you use.

To maximise your potential savings, you should use as much solar-generated electricity as you can, limiting your grid consumption. That way, you’ll save up to 22 to 28 cents for every kWh of solar power you consume. These price indexes are inclusive of GST.

What is the Average Payback Period for an 8 kW Solar System?

The average payback period is when you expect to get a complete return on your investment. For an 8kW solar system, the payback period is on average, 3.24 years after solar panel installation.

Your savings with a solar PV system begins from the day of its instalment. If you follow all the guidelines on how to maximise your savings from solar, you can expect an average payback period of 3 to 5 years.

Below is a table showing the average payback period for an 8kW solar system for each major capital city.

CitySystem CostPeak Sun HoursDaily Energy Production Electricity TariffFeed-In TariffEnergy UsageDaily SavingsAnnual SavingsPay Back Perid (Years)
Adelaide$8,500.004.7037.60$0.38$0.1250%$9.36$3,416.592.49
Brisbane$8,500.005.0040.00$0.28$0.1250%$8.00$2,920.002.91
Canberra$8,500.004.4035.20$0.23$0.1250%$6.16$2,248.403.78
Darwin$8,500.005.5044.00$0.27$0.0850%$7.59$2,770.353.07
Hobart$8,500.003.7029.60$0.25$0.06550%$4.66$1,702.174.99
Melbourne$7,000.004.1032.80$0.20$0.1250%$5.25$1,915.523.65
Perth$8,500.005.3042.40$0.29$0.1050%$8.27$3,017.822.82
Sydney$8,500.00$4.6036.80$0.24$0.1550%$7.18$2,619.243.25

You’ll be able to get a total return on your $6,000 to $12,000 worth of initial investment in solar panels after 3 to 5 years of savings in your electricity bills. After that, whatever you save will be a surplus.

However, you’ll need to update your solar inverter every 15 to 20 years to ensure consistent solar system power.

How Long Will an 8 kW Solar System Last?

Like most solar systems, the average lifespan of an 8kW system is 25 to 30 years.

According to the National Renewable Energy Laboratory, solar panels face an average efficiency drop of 0.8% each year. This performance decline is called the solar degradation rate, and it varies among manufacturers. For instance, some solar industry brands claim a degradation rate as low as 0.3%, while other substandard solar systems devalue much faster.

What is the solar degradation rate? Simply put, panels become less efficient at producing electricity over time and their solar system output also decreases. This process is called degradation, and it can take up to 30 years for any high-quality solar system to suffer its effects.

However, despite several decades of use, panels don’t lose their value. Rather, their energy output decreases slightly below the solar company specifications. Light & Elevated Temperature Degradation (LetiD) is the name given to this phenomenon. Better quality panels will last longer and resist this degradation.

Solar panels are incredibly sturdy and last decades with little to no maintenance. They are designed to withstand strong winds and hail storms, so having your system demolished due to weather conditions is highly unlikely. Still, you can ensure more power over the years via the following methods:

  • Regular maintenance

Get your system regularly checked by your solar installation experts or operational and maintenance personnel. A routine inspection by a professional team will ensure that the system has no loose connections or insecure parts in the framework.

  • Clearing out dust and debris

Don’t let dust or debris accumulate on top of your solar panels. Debris can block the solar panels from absorbing sunlight and reduces their efficiency.

How Much Power Does an 8 kW Solar System Produce?

An 8kW solar system with high-quality parts and maintenance produces 37.7kW of energy per day. This figure is dependent on several factors however..

8kW solar systems are suitable for small commercial settings or large households with above-average energy expenditure. Understandably, their energy production has to be equally generous to meet the needs of its target settings.

On average, a high-quality solar PV system that’s suitably maintained generates approximately 37.3kW across each major city. This output is well within the demands of an extensive household or smaller business.

The table below shows the average system production for each major city, and the amount of peak sun hours that the system receives.

CitySystem SizePeak Sun HoursTotal Production (kWh)
Adelaide8kW4.737.6
Brisbane8kW540
Canberra8kW4.435.2
Darwin8kW5.544
Hobart8kW3.729.6
Melbourne8kW4.132.8
Perth8kW5.342.4
Sydney8kW4.636.8

However, several factors influence how you optimise your system’s production.

  • Geography: Some areas receive more sunlight than others. Your system’s output depends on where you live.
  • Weather conditions: Sunny days create massive increases in electricity production. When it’s overcast, you’ll notice a dip in your system’s contribution. Extreme heat also lowers system efficiency when the panels overheat.
  • Roof pitch: The height of your roof also determines solar energy output.
  • Orientation of the panels: The engineers installing your solar system will calculate an ideal tilt angle for your panels based on your roof’s height, direction, and angle upon which the sun rays reach. They will then adjust your panels to receive optimum sunlight throughout the day.
  • Quality of the panels: Your solar panel quality significantly affects how much energy the system produces. The best solar panels produce the most electricity, while the power output from lower-grade systems is subpar.
  • Peak sun hour (PSH): This is crucial for the amount of energy your system produces. It’s the hour when the sun is brightest, and your solar energy system generates peak output. Sunshine is strongest around 12 p.m. noon in most places. The sun’s strength also declines during early mornings and late afternoons, lowering production rates.

Will an 8kW Solar System Power Your Home?

If your household electricity needs are between 30 to 40 kWh, then 8kW is the right solar system for you.

A solar energy system installed on your rooftop provides a cleaner form of energy and saves you a tidy sum on your electricity bills.

8kW is an affordable, reliable, and value-adding alternative to the 5kW system. The extra power output contributes a lot to the power generation capacity without adding as much to the cost. Plus, if you buy quality solar panels, they’ll last you over three decades.

To help you decide whether an 8kW solar system is enough to power your home, you should first figure out your daily electricity consumption. If the value falls between 30 to 40 kWh, then an 8kW system is the perfect fit for you.

If you’re a small business owner and want to curb your energy expenses to retain the most profit from your venture, an 8 kW solar system is also a practical choice. 

Can I Install a Battery with an 8 kW Solar System?

Installing a solar system with a solar battery storage option is an expensive but valuable investment. It will store excess solar power and let you use your generated electricity even at night.

An 8kW solar system is generally installed in homes with significant energy needs. Even then, the power output during the daytime exceeds most households’ requirements. Thus, installing a solar panel system with a solar battery makes sense.

An 8kW solar system has roughly 35 units of electricity per day. Most setups require only 40% of this amount when the sun is out and 70% when it sets. You can store the excess solar power in a solar battery for later use.

While buying battery storage for your system, you must look for an optimum capacity. Purchasing a smaller unit won’t fulfill your needs, and larger units can be pricey. 22.4 kWh is the ideal storage capacity for your system’s batteries.

Installing a solar PV system with a solar battery will also add a considerable amount to the net cost of your system, prolonging the time you need for payback. So, it’s vital to buy a high-quality one to avoid malfunction and additional repair or replacement costs.

Should I Consider a Larger or Smaller System?

The right solar system size for your house depends on your energy usage, rooftop space, and budget. You should consider these notables before installing a solar system.

Solar systems are the need of the hour, with electricity prices rising daily and non-renewable fuels depleting rapidly. And with a handy battery storage option, their efficiency knows no limits.

The size of the solar system you need for your home or business depends on your average energy expenditure, the available roof space, and your budget. Here’s each of them explained:

  • Energy expenditure: You need a system that offsets your energy usage by a significant margin to save considerable money on your electricity bills.
  • Available space for installation: Solar systems require a lot of roof space. You should consider whether you have access to accessible roof space and if that space is enough to house the solar system you desire.
  • Budget constraints: Budget is a common constraint in solar system installation for most Australians since solar systems can be rather expensive.

How Do I Calculate My Actual Power Output?

  1. Your annual electricity needs: First, calculate how much electricity you consume on average. You’ll need to inspect your electricity bills from the past twelve months to determine the average amount, with the peaks and valleys of your energy use. You’ll probably notice that your electricity usage increases in the summer months due to air conditioning and in the winter months due to heating systems.
  2. Your monthly electricity needs: Now, divide the sum of your electricity consumption over the past year by 12 to calculate your average monthly usage.
  3. Your daily electricity needs: Finally, you can divide your monthly consumption by 30 to estimate how much electricity you use daily.

You can accurately find your actual power output by comparing this consumption table with several everyday-use electric appliances:

Electric appliancePower consumption
Light 11 W
Fan 80 W
Refrigerator (200 L)120 W
Washing machine300 W
Microwave 1,500 W
Air conditioner (1.5 HP)1,125 W
Television150 W
Water pump200 W
Electric cooker300 W

Whether or not you can use these appliances with solar power at night depends on your battery storage.

What other systems are there?

There are a number of system sizes to choose from including:

3kW Solar System

5kW Solar System

6.6kW Solar System

10kW Solar System

Get Started!

Interested in getting solar for your home? By clicking below you can use our smart solar calculator to find out just how much you could save with solar, what incentives you’re eligible for, and the positive impact you’ll have on the environment.

Don’t wait until next quarter’s bloated bill, and get started today!

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Join over 20,000 homeowners who have made the switch with Instyle Solar, or the 1000+ positive reviewers who have been more than happy with their solar install.

Otherwise, you can always contact us on 1300 133 556, or email us at [email protected].

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