The right size solar system depends on how much electricity your home uses, how much of it you can use during daylight,
and whether you plan to add a battery. Adjust your usage below — we will recommend a system size and battery capacity that
fit your home, wherever you are. For a full system design with more trade-offs, open our
Solar & Battery Designer.
Based on:— kWh/day usage
·— kW solar
·— kWh battery
·typical tariffs
Solar & Energy Savings
How solar reduces your electricity bills
The calculations below compare your current power bill with what your bill would look like once solar and — if you choose one — a battery are installed. Your
Old Bill
of
-
per month
(-
annually)
is calculated from your total energy consumption multiplied by the grid electricity rate. Your
New Bill
of
-
per month
(-
annually)
accounts for solar generation, the percentage you use directly (self-consumption), remaining grid consumption, and feed-in credits for excess energy exported to the grid. This results in
monthly savings of -
(-
annually).
Calculating...
Monthly Savings
$0
Annual savings: $0 | Bill Savings: 0%
Your inputs
Adjust the numbers below to match your household. The recommendation above updates as you move each slider.
Your energy usage
Your power bill depends on how much electricity you use each day, what your retailer charges per kWh,
and how much solar energy you actually use at home versus export back to the grid.
The more accurate these three numbers, the more useful the estimate.
5 kWh100 kWh
$/kWh
$/kWh
$/kWh
%
lightbulbNote: These are simplified estimates. For detailed tariff inputs and advanced calculations, use the full Photonik app.
Representative flat export rate (feed-in tariff). What you earn per kWh of surplus solar exported to the grid. Your actual rate depends on your provider, plan, and time of day.
Estimated at 75% of the retail grid rate. A battery lets you store daytime solar and export during expensive peak hours, so each exported kWh is typically worth more than a flat feed-in tariff. Real returns depend on your time-of-use tariff and battery efficiency.
A bigger solar system generates more electricity — but only what you use (directly or via a battery)
saves you full retail price; the rest is sold back at the feed-in tariff, which is usually lower.
There's a sweet spot where extra panels stop paying for themselves quickly.
1 kW20 kW
lightbulb
A 8 kW system in Australia can generate approximately 12446.0 kWh annually based on local sun conditions.
Battery size
A battery stores solar energy generated during the day so you can use it at night, instead of buying
electricity from the grid. In markets where retail power costs far more than the feed-in tariff,
a battery can materially increase your savings. In markets with high feed-in tariffs, batteries add
smaller savings and are usually a decision about independence rather than payback.
0 kWh30 kWh
lightbulb
A 0kWh battery will make you about 0% self sufficient.
The sweet spot for most households is 5 – 13 kWh — larger batteries add independence but with diminishing payback, especially where feed-in tariffs are low.
Price estimate
Based on your inputs above, here's a rough price for the system. It's a planning-stage estimate
before rebates or incentives, and real installer prices vary by brand, location and roof complexity.
For a real, no-obligation price, use the Get quotes button.
Calculating...
Estimated Solar & Battery Price
0
%
Adjust tax rate if needed
How this recommendation works
The ranges above use your daily usage, self-use pattern, and a typical generation profile for your country.
They are a starting point for conversations with installers — not a substitute for a site-specific design,
wiring protection study, or equipment selection.
The savings teaser uses the same bill model as our
savings calculator — open it for a fuller breakdown.
Frequently asked questions
Is this a final system design?
No — it is a planning-stage recommendation based on typical generation profiles and your inputs.
A certified installer should validate wiring, protection, and equipment for your site.
Why is battery size a range?
Battery value depends on how much of your usage happens after sunset and on local retail vs feed-in prices.
The slider and recommendation are heuristics to help you explore trade-offs, not a substitute for a full load analysis.
Ready to get quotes?
When you are happy with a rough size, use Photonik or talk to installers for a firm price and design.
