8kW solar system quick summary
An 8kW solar system is built for medium to larger households that run several big appliances during the day or simply use more electricity than average.
You will need 18–22 panels and an 8kW inverter. This system will typically produce 28–34 kWh per day.
This system will cover 35–45 m² of roof area. That’s enough to cover most daytime usage in a large family home while still exporting a solid amount back to the grid.
Table of contents
How much does an 8kW solar system cost?
In our experience, most 8kW systems land between $7,600 and $9,600 using mid-range panels and reputable installers.
Prices vary slightly across states due to labour costs, local competition and the amount of sunlight each region receives.
| Quality | Cost |
|---|---|
| Budget System | $7,100 |
| Mid-Range System | $8,200 |
| Premium System | $9,650 |
Average 8kW Solar System Cost by City (Australia)
These prices assume typical suburban installations. Higher-efficiency panels, multi-storey homes, complex roofs or premium inverter brands may push the system into a higher range.
| City | Average cost |
|---|---|
| Adelaide, SA | $8,850 |
| Brisbane, QLD | $8,100 |
| Canberra, ACT | $9,100 |
| Hobart, TAS | $9,600 |
| Melbourne, VIC | $9,506 |
| Sydney, NSW | $8,900 |
| Perth, WA | $9,250 |
| Darwin | $8,668 |
How Much Solar Power Does an 8kW Solar System Produce?
We’ve found that households with north-facing roofs consistently sit at the higher end of the 28–34 kWh/day range.
This will, however, depend on your state, roof angle and shading. North-facing roofs with good orientation sit at the higher end, while south or mixed-facing arrays trend lower.
Here’s a rough breakdown of typical daily output by location:
- QLD: 32–34 kWh/day
- WA: 31–33 kWh/day
- NSW: 29–32 kWh/day
- SA: 28–31 kWh/day
- VIC: 26–29 kWh/day
- TAS: 24–27 kWh/day
Seasonal swings matter too. You’ll see strong summer production and slightly softer outputs in winter, but an 8kW system will still cover a large chunk of daytime household usage year-round.
How Many Solar Panels for an 8kW Solar System?
Most 8kW systems use 18–22 solar panels, depending on the wattage of the panels you choose.
Modern residential panels range from 370–440W each, and this wattage determines how many panels are needed.
Typical configurations look like this:
- 370W panels → ~22 panels
- 415W panels → ~19–20 panels
- 440W panels → ~18 panels
Higher-efficiency panels reduce the required area, making it easier to fit the system on roofs with limited space.
You’ll need around 31–38 m² of usable roof space for an 8kW solar system, depending on the wattage and dimensions of the panels.
What can an 8kW solar system run?
An 8kW system can comfortably run several major appliances during the day while still exporting excess energy. With 28–34 kWh of daily production, most households can run:
- Air conditioning
- Pool pumps
- Electric hot water
- Fridges and freezers
- Washing machines and dryers
- Computers, TVs and general household loads
Night-time usage is still drawn from the grid unless paired with a battery, but during daylight hours an 8kW array covers most modern household demand.
| Appliance | Hours per day | Watts Per Hour | Total Daily Use |
|---|---|---|---|
| Lights | 12 | 11W | 132W |
| Computer | 1 | 150W | 150W |
| Refrigerator(300L) | 24 | 120W | 2,800W |
| Washing machine | 0.5 | 300W | 150W |
| Microwave | 0.1 | 1,500W | 150W |
| Air conditioner (1.5HP) | 2 | 1,125W | 2,250W |
| Pool Pump | 2 | 750W | 1400W |
| Colour TV (50 inch) | 3 | 150W | 450W |
| Total | 7,482W | ||
Is an 8kW solar system worth it?
In my experience, yes! — most homeowners see a 4–6 year payback period from an 8kW solar system, depending on usage and feed-in tariffs. The system offsets a significant amount of daytime consumption, reducing electricity bills while generating consistent export income.
Homes with higher daytime usage — EV charging, pool pumps, air con — generally get the fastest paybacks because they self-consume more of their generated power. Even on lower-use days, exported energy still contributes meaningful savings.
How much roof space do you need for an 8kW system?
You’ll need around 35–45 m² of usable roof space for an 8kW solar system, depending on the wattage and dimensions of the panels. Higher-efficiency panels reduce the required area, making it easier to fit the system on roofs with limited space.
Orientation also matters. North-facing is ideal, but east/west arrays work well if you have enough surface area to spread the panels.
8kW solar system specifications
Below is a typical specification sheet for a modern 8kW solar system:
| Specification | Typical Range |
|---|---|
| System size | 8kW |
| Daily output | 28–34 kWh/day |
| Number of panels | 18–22 panels |
| Panel wattage | 365–450W |
| Inverter size | 8kW–8.2kW |
| Roof space | 35–45m² |
| Annual output | 10,200–12,400 kWh |
| Typical household size | Medium–large homes |
We have found that households selecting higher-efficiency panels often see more consistent production across seasons and slightly better annual output.
8kW solar system with battery storage
An 8kW solar system generates an average of 35kw per day. Since you will need about 70% power at night and 30% to 40% during the day, a battery with a storage capacity of 22.4Kwh will be ideal.
Keep in mind that battery storage is quite costly and may increase your payback period. For this reason, ensure you buy high-quality batteries to maximise reliability, performance, and lifespan.
Battery storage cost for a 8kW system
As discussed, you will need a battery size of about 22 – 24kWh. Below are some examples of battery brands and their cost.
| Brand | Cost | After Rebate |
|---|---|---|
| Tesla Powerwall 2 (26kW) | $21,000 | $17,200 |
| Sonnen EVO (20kW) | $16,400 | $12,650 |
| BYD (22kW) | $16,220 | $12,470 |
Note: These battery costs are RRP and do not include installation. Installation usually costs $1,500 – $2,000, but installers also get discounts on RRP.
8kW vs 6.6kW vs 10kW solar system
Here’s how an 8kW solar system compares with nearby system sizes:
- 6.6kW – 6.6kW solar systems have a lower upfront price, but also lower output. Best for small-to-medium homes.
- 8kW – Strong balance of system price, power output and roof space.
- 10kW – Best for large households, a 10kW system is ideal for EV charging, ducted air con, pools, or homes planning for all-electric upgrades.
We’ve found that 8kW is ideal for households using 25–35 kWh/day, especially if they run appliances during the day.
👉 Pro tip: For more information on sizing a system for your needs, see our Solar System Sizing Guide.
Seasonal output for an 8kW solar system
Solar energy production changes across the year:
- Summer: 32–36 kWh/day
- Autumn: 26–30 kWh/day
- Winter: 20–26 kWh/day
- Spring: 30–34 kWh/day
Seasonal fluctuation is normal for all residential solar systems. Good panel placement ensures reliable annual performance.
State-by-state output guide
Average daily production by state:
| State | Output |
|---|---|
| QLD | 32–35 kWh |
| NSW | 28–32 kWh |
| VIC | 24–28 kWh |
| SA | 30–33 kWh |
| WA | 31–34 kWh |
| TAS | 20–25 kWh |
| NT | 34–36 kWh |
Your actual power output depends on solar panel orientation, shading, and local climate conditions.
Compare Quotes from Local Installers
GoSolarQuotes.com.au matches you with three local solar installers voted #1 by previous users in your area.
“No hard sales, just friendly advice, and great prices”
- Click here and enter your Postcode.
- Answer a few simple questions about your power consumption needs.
- Your solar job details are forwarded to three top-rate and heavily vetted solar installers.
- No hard sales, just friendly advice and great value for money.
FAQ's
Yes. An 8kW system provides enough solar power for most medium-to-large households.
Between 28–34 kWh/day, depending on location and roof orientation.
This depends on the output of the individual panel in the system. If you use 250W panels, you will need 32 panels to reach 8,000W (8kW) output.
But if you use better quality 400W panels, you will only need 20 panels for the same 8,000W ouput.
Yes. An 8kW system provides enough solar power for most medium-to-large households, especially those using 25–35 kWh per day. Homes that run major appliances during daylight hours will see the strongest benefits and highest bill reductions.
An 8kW solar system generates around 28–34 kWh per day, depending on your location, climate and roof orientation. North-facing panels usually deliver the highest output, while east/west arrays still produce reliable solar energy across morning and afternoon periods.
Most 8kW installations require 18–22 solar panels, depending on panel wattage. Higher-efficiency panels reduce the total number needed, which can help when roof space is limited or when installers need to split the array across multiple roof faces.
Yes. All residential solar systems under 100kW qualify for Small-scale Technology Certificates (STCs), including an 8kW installation. The STC rebate reduces the upfront price significantly, and we’ve found it helps improve overall system payback for most households.
