Sizes
6kW & 6.6kW Solar Systems: Costs, Output, and Returns
6kW and 6.6kW solar panel system size is the most trending size in Australia. I explain in detail the 6kW and 6.6kW solar power systems to make it easy for you to decide which one is best for you. I start from the Cost, dimensions, by major cities in Australia, the national price index, history, output, return, and finally, why Fordan is the best solar company in Australia.
How much does a 6kW & 6.6kW solar system cost?
In Australia, a 6kW solar system costs between $5,200 and $8,700, while a 6.6kW system ranges from $5,500 to $9,000. These prices include the federal STC rebate and depend on factors like location and equipment quality.
| System Size | Cost Range (AUD) |
|---|---|
| 6kW | $5,200 – $8,700 |
| 6.6kW | $5,500 – $9,000 |
How many panels are in a 6.6kW solar system? How much area is required?
A 6.6kW solar system typically uses 17 to 20 panels, each around 370-400W. Each panel is approximately 1.7m² (18.3 ft²), with dimensions of 66.9 inches long by 39.4 inches wide (1.7m x 1.0m). Total area required is 28.9m² to 34m² (310 ft² to 366 ft²), depending on panel efficiency and spacing. For a 6kW system, expect 15 to 16 panels, needing 25.5m² to 27.2m² (274 ft² to 293 ft²).
How much roof space is needed for a 6kw & 6.6 kW solar system?
A 6kW system requires 25.5m² to 27.2m² (274 ft² to 293 ft²), while a 6.6kW system needs 28.9m² to 34m² (310 ft² to 366 ft²). These figures use standard 1.7m² panels and account for layout efficiency, as per 2025 Australian installation data. The range reflects panel wattage and roof design variations.
What are the Dimensions of the 6.6kw solar system?
Standard solar panels for both 6kW and 6.6kW systems measure 1.7m x 1.0m (5.6 ft x 3.3 ft). A 6.6kW system with 17-20 panels covers 28.9m² to 34m², while a 6kW system with 15-16 panels spans 25.5m² to 27.2m².
| System Size | Panel Dimensions | Total Panels | Total Area |
|---|---|---|---|
| 6kW | 1.7m x 1.0m (5.6 x 3.3 ft) | 15-16 | 25.5m² – 27.2m² |
| 6.6kW | 1.7m x 1.0m (5.6 x 3.3 ft) | 17-20 | 28.9m² – 34m² |
What are the 6 kW and 6.6 kW solar panel sizes in major cities of Australia?
Panel sizes remain consistent across Australia’s major cities, typically 1.7m x 1.0m for both 6kW and 6.6kW systems.
6kW System Table:
| City | Panel Size | Panels Needed |
|---|---|---|
| Sydney | 1.7m x 1.0m | 15-16 |
| Melbourne | 1.7m x 1.0m | 15-16 |
| Brisbane | 1.7m x 1.0m | 15-16 |
| Perth | 1.7m x 1.0m | 15-16 |
6.6kW System Table:
| City | Panel Size | Panels Needed |
|---|---|---|
| Sydney | 1.7m x 1.0m | 17-20 |
| Melbourne | 1.7m x 1.0m | 17-20 |
| Brisbane | 1.7m x 1.0m | 17-20 |
| Perth | 1.7m x 1.0m | 17-20 |
National Solar Price Index – 6kW & 6.6KW
The latest July 2025 National Solar Choice Price Index in Australia lists 6kW systems at $0.89 per watt ($5,340 total) and 6.6kW systems at $0.89 per watt ($5,874 total), post-STC rebate.
| System Size | Price per Watt | Total Cost (AUD) |
|---|---|---|
| 6kW | $0.89 | $5,340 |
| 6.6kW | $0.89 | $5,874 |
National Solar Price Index – 6kW
What Is The Cost Of 6kw & 6.6kw Solar systems for residential & Commercial?
Residential: 6kW systems cost $5,200-$8,700; 6.6kW systems cost $5,500-$9,000. Commercial: Pricing aligns closely, with 6kW at $5,200-$8,700 and 6.6kW at $5,500-$9,000, varying by scale and installation specifics.
Residential Table:
| System Size | Cost Range (AUD) |
|---|---|
| 6kW | $5,200 – $8,700 |
| 6.6kW | $5,500 – $9,000 |
Commercial Table:
| System Size | Cost Range (AUD) |
|---|---|
| 6kW | $5,200 – $8,700 |
| 6.6kW | $5,500 – $9,000 |
What is The History of 6kW solar system prices in Australia?
In 2012, a 6kW solar system in Australia cost $12,000-$15,000. Prices fell steadily due to improved technology and market growth, reaching $8,000-$10,000 by 2018. By 2025, costs have stabilized at $5,200-$8,700, reflecting rebates and competition.
How much should a 6kw & 6.6 kW solar system generate in average output?
The average output of a solar system is a measure of how much electricity it generates daily or annually, influenced by factors such as location, sunlight availability, panel orientation, and system efficiency. In Australia, where solar adoption is widespread, these figures are well-documented based on typical conditions.
For a 6kW solar system, the average daily output ranges from 24 kWh to 30 kWh. This assumes 4 to 5 peak sun hours per day, which is common across most Australian regions. Over a year (365 days), this translates to an annual output of approximately 8,760 kWh to 10,950 kWh. The variation depends on geographic factors—systems in sunnier northern areas like Queensland may hit the higher end, while southern regions like Tasmania might lean toward the lower end due to fewer sunlight hours.
A 6.6kW solar system, with its slightly larger capacity, generates between 26 kWh and 33 kWh per day. Annually, this equates to 9,490 kWh to 12,045 kWh. The increased panel capacity allows it to capture more sunlight, making it particularly effective in areas with consistent solar exposure. Like the 6kW system, its performance is optimized with north-facing panels, minimal shading, and high-quality components.
Table: Average Daily and Annual Output
| System Size | Daily Output (kWh) | Annual Output (kWh) |
|---|---|---|
| 6kW | 24 – 30 | 8,760 – 10,950 |
| 6.6kW | 26 – 33 | 9,490 – 12,045 |
For instance, a 6kW system producing 27 kWh daily could power a medium-sized household’s needs (e.g., lighting, appliances, and air conditioning), while a 6.6kW system’s extra output offers a buffer for higher consumption or future energy demands.
What is the output with batteries for a 6kW and 6.6kW solar system?
Adding batteries to a solar system changes how its output is utilized, allowing excess energy generated during the day to be stored and used when the sun isn’t shining—such as at night or during cloudy weather. The “output with batteries” refers to the amount of stored energy available for later use, rather than the system’s total generation capacity.
For a 6kW solar system, a typical battery size is 10 kWh to 15 kWh. If the system generates 24-30 kWh daily and the household consumes 10-15 kWh during daylight hours, the remaining 9-15 kWh can be stored. Modern batteries, like the Tesla Powerwall or LG Chem, have efficiencies of 90-95%, meaning a 10 kWh battery provides 9-9.5 kWh of usable energy. This stored energy can cover evening usage (e.g., 5-10 kWh for lighting, TV, and appliances), reducing reliance on the grid.
A 6.6kW solar system often pairs with slightly larger batteries, typically 13.5 kWh to 20 kWh. With a daily output of 26-33 kWh, and assuming daytime usage of 10-15 kWh, the battery could store 11-18 kWh. For example, a 13.5 kWh battery (common with a 6.6kW system) offers about 12-13 kWh of usable energy, enough to power a home overnight or during outages. The larger system and battery combo maximizes energy independence, especially for homes with higher evening demand.
Batteries enhance flexibility—rather than exporting excess power to the grid at a low feed-in tariff (e.g., 8-10 cents/kWh), you can use it later when electricity rates might be 30-40 cents/kWh. The actual output depends on consumption patterns, battery size, and charge/discharge efficiency.
How much should a 6kw & 6.6 kW solar system generate in Different seasons?
Solar generation fluctuates with the seasons due to changes in sunlight hours, angle, and weather conditions. Below, we break down the output for each system size across all four seasons in Australia, assuming optimal setup (north-facing panels, no shading).
6kW Solar System
- Summer: 28-35 kWh/day – Longer days and higher solar intensity boost output, ideal for meeting peak air conditioning demands.
- Autumn: 22-28 kWh/day – Shorter days and lower sun angles reduce generation, though still substantial for most households.
- Winter: 15-20 kWh/day – Shortest days and weaker sunlight lead to the lowest output, often requiring grid or battery support.
- Spring: 24-30 kWh/day – Increasing daylight and clearer skies bring output back toward summer levels.
6.6kW Solar System
- Summer: 30-38 kWh/day – The extra capacity shines here, potentially covering all daytime needs and charging a battery fully.
- Autumn: 24-30 kWh/day – Consistent with the 6kW trend but with a slight edge, supporting moderate usage patterns.
- Winter: 16-22 kWh/day – Even in the leanest season, output remains viable for basic needs, with batteries bridging gaps.
- Spring: 26-33 kWh/day – A strong rebound makes this system a robust choice year-round.
How much Savings and payback on 6kw& 6.6kW solar systems?
Savings and payback periods for solar systems hinge on electricity costs, system price, energy production, and incentives like Australia’s Small-scale Technology Certificates (STC) rebate. Here’s a detailed breakdown based on 2025 data.
A 6kW solar system typically saves $1,500 to $2,000 annually on electricity bills. This assumes an electricity rate of 30 cents/kWh, a feed-in tariff of 8-10 cents/kWh, and an annual output of 8,760-10,950 kWh. If a household uses 70% of the energy (self-consumption) and exports the rest, savings come from offsetting grid purchases and earning feed-in credits. Installation costs range from $5,200 to $8,700 after rebates, yielding a payback period of 5 to 7 years. Over a 25-year lifespan, total savings could reach $37,500-$50,000.
A 6.6kW system offers slightly higher savings of $1,650 to $2,200 per year, thanks to its 9,490-12,045 kWh annual output. Costing $5,500 to $9,000 after rebates, its payback period is 4.5 to 6.5 years. The faster payback reflects economies of scale—more energy for a marginally higher price. Lifetime savings might exceed $41,250-$55,000, making it a strong financial choice for larger households or those planning for electric vehicles.
What is the Cost advantage compared to 5kW systems?
The cost advantage of 6kW and 6.6kW systems over a 5kW system lies in their lower cost per watt and higher energy yield for a modest price increase. A 5kW system costs $4,500-$7,000 and generates 20-25 kWh/day (7,300-9,125 kWh/year), equating to $1.00-$1.40 per watt. A 6kW system, at $5,200-$8,700, produces 24-30 kWh/day ($0.87-$1.45 per watt), while a 6.6kW system, at $5,500-$9,000, delivers 26-33 kWh/day ($0.83-$1.36 per watt).
The 6.6kW system often uses a 5kW inverter (approved for grid connection), avoiding the higher cost of a 6kW inverter, enhancing its value. For roughly 20-32% more upfront cost, you get proportionally more energy, making larger systems more economical long-term, especially as electricity rates rise.
Are 6.6kW systems the new 5kW system?
Yes. In 2025, 6.6kW systems have become the go-to choice for Australian homes, overtaking 5kW systems due to falling solar prices, rising energy demands, and the ability to pair 6.6kW panels with cost-effective 5kW inverters.
What is the difference between “6.6 kW vs 10kw solar system”?
The main difference between a 6.6kW and a 10kW solar system is their capacity, energy output, cost, and ideal use. A 6.6kW system suits medium-sized households with moderate energy needs, while a 10kW system is designed for larger homes or small businesses with higher consumption, offering more power but requiring greater investment and space.
Table: 6.6kW vs 10kW Solar System Comparison
| Feature | 6.6kW System | 10kW System |
|---|---|---|
| Daily Output | 26-33 kWh | 40-50 kWh |
| Annual Output | 9,490-12,045 kWh | 14,600-18,250 kWh |
| Typical Cost (AUD) | $5,500 – $9,000 | $9,000 – $14,000 |
| Panels Required | 17-20 | 25-30 |
| Roof Space Needed | 28.9m² – 34m² | 42.5m² – 51m² |
| Best For | Medium households | Large households/small businesses |
What are the other solar system sizes mostly used in Australia?
Australia’s common solar system sizes include 3kW, 5kW, 6.6kW, and 10kW, depending on your energy needs and property types. These range from small setups for apartments to larger systems for family homes or businesses. For more details, see our guide on the best solar panel system sizes.
Table: Common Solar System Sizes in Australia
| System Size | Typical Use Case |
|---|---|
| 3kW | Small households or apartments |
| 5kW | Medium households |
| 6.6kW | Medium to large households |
| 10kW | Large households or small businesses |
How does the “solar rebate ” play a role in solar panel sizes?
The solar rebate, via Australia’s STC program, lowers upfront costs based on system size and location, with larger systems like 6.6kW or 10kW earning more certificates and thus bigger discounts.
Is a 6kw& 6.6kw solar system right for you?
Yes, if your daily energy use is 20-30 kWh and you have enough roof space.
How to Avoid Cheap 6kW & 6.6kW Systems?
Low-quality solar systems can lead to poor efficiency and higher costs over time. To steer clear:
- Verify certifications: Look for CEC-approved panels and inverters.
- Choose trusted brands: Go with names like Jinko, LONGi, or Fronius.
- Compare quotes: Watch for suspiciously low prices.
- Check reviews: Confirm installer reliability.
- Confirm warranties: Aim for 10-25 years on components.
Do we need inverters for 6kW and 6.6kW solar systems?
Yes, inverters are necessary to convert solar panels’ DC electricity into AC power for home use. A 6kW system typically uses a 5kW inverter, and a 6.6kW system often pairs with a 5kW inverter too, balancing efficiency and grid compliance.
Why should you get your solar panel installation from Fordan Solar?
Fordan Solar provides high-quality installations with premium components, expert design, and strong warranties, ensuring top performance and customer satisfaction.