What size solar system do I need in Victoria?
Size follows your bill and your usage, not your roof area. In Victoria, at 30c a unit, a household on a $510 quarterly bill is using around 15 kWh a day and wants roughly 6.6kW solar.
What is different about Victoria
At 30c a unit Victoria sits 4th of 8 on retail price, and one of the lowest feed-in tariffs at 1c, so exporting is close to giving power away and self-consumption carries the entire case. It averages 4.6 peak sun hours a day.
By household, in Victoria
| Household uses | Their bill a quarter | System | After rebates | Saves a year | Pays for itself |
|---|---|---|---|---|---|
| 10 kWh | $373 | 5–6.6kW solar | $4,070 to $6,100 | $350–$530 | 9–10+ years |
| 15 kWh | $510 | 6.6kW solar | $4,850 to $6,850 | $500–$750 | 8–10 years |
| 22 kWh | $701 | 10–13kW solar | $6,600 to $11,600 | $760–$1,140 | 7–10+ years |
| 30 kWh | $919 | 10–13kW solar | $6,600 to $11,600 | $990–$1,480 | 6–9 years |
The bill column is what that household pays here at 30c a unit.
Why bigger is not automatically better
Every extra panel generates more, but the extra generation is only worth 30c if you are home to use it and 1c if you are not. In a state with a 1c feed-in rate, a system sized well past your daytime consumption is producing power worth almost nothing for most of its output.
That is the real limit on sizing here, and it is why the honest answer depends on occupancy. The same 15 kWh household saves $640–$960 home most days and $390–$580 out all day, on the identical system.
Things that legitimately push you bigger
An electric car, which adds about 4.8 to 9 kWh a day. A pool pump, which is a large load you can run in the middle of the day. Electric hot water on a daytime cycle. Moving off gas. All of them raise daytime consumption, which is the only thing that makes extra capacity pay.
Roof space is rarely the constraint. A 6.6kW array is about 15 to 16 panels and fits on most single-storey roofs. If an installer leads with how many panels will fit rather than what you use, that is a sizing conversation running backwards.
$2,000 difference.
That is the gap between two quotes for the same 6.6kW system in Victoria, in the same week. Not build quality, not a better job. Overheads, how full the diary is that month, and what the person at your kitchen table thinks you will agree to. On solar with a battery the same gap is $7,900.
Closing that gap is what I do. I already know what installers in your area are quoting this month for this equipment, so I get you the bottom of that range for the same system other companies charge thousands more for. It costs you nothing. The installer pays me, and only if you go ahead, which is why there is no reason for me to push you at a bigger system than you need or at a dearer installer.
Get your own numbers, then get them priced properly
The table above is four example households. Two minutes of questions gets you your system size, what it should cost after rebates in Victoria, and a ten-year projection built on your roof and your usage. Then I find the bottom of that price range for you.
Run my numbers, freeNo installer buys placement or ranking here, and nothing reaches an installer unless you ask.
Common questions
What size solar system do I need in Victoria?
A household on a $510 quarterly bill, using about 15 kWh a day, wants roughly 6.6kW solar. Larger bills move up from there.
Is a bigger solar system always better?
No. Extra generation you are not home to use is worth only 1c a unit in Victoria, against 30c for power you use as it is made.
What makes a bigger system worth it?
Daytime load. An EV, a pool pump, electric hot water on a day cycle, or someone home during the day.