Solar panel checker: see your roof, then see your savings
Enter your address and we show your actual roof from above, how many panels fit, the sunshine it gets and what a system that size would knock off your bill. Upload a bill for a result based on your real usage.
Your bill is encrypted the moment it lands on our server, is never shared, and is deleted automatically after 30 days unless you ask us for a quote. Only the QVolt team can open it.
Four steps from an address to a savings figure
Everything on this page runs in your browser and on our server. No app, no site visit, and nothing is stored until you ask for your results.
Tell us how much power you use
Upload your latest electricity bill and we read the usage off it, or type in your quarterly bill or daily kWh. Your bill is encrypted the moment it arrives.
See your roof from above
Type your address and Google's Solar API returns your roof: its shape, which way each face points, how much sun it gets and where panels fit best.
Slide the panel count, watch the savings
We size a system to your usage. Add or remove panels and the roof drawing, the yearly output and the savings all update on the spot.
Unlock the full breakdown
Pop in your email to see your bill before and after, 25-year savings, export income and payback. We send you a copy so you can compare quotes.
What Google's Solar API actually knows about your roof
Most online solar estimators start and end with a postcode. They assume an average roof, an average amount of shade and an average system, then hand you an average number. The Google Solar API works the other way round. Google has flown high-resolution aerial imagery over most Australian cities and built a three-dimensional surface model from it, so for a single building it can tell you how big the roof is, how many separate faces it has, how steeply each one is pitched and which way each one points.
On top of that model Google simulates a full year of sun. It tracks the sun's path across the sky for every hour of the year, accounts for the shadows thrown by trees, chimneys and neighbouring buildings, and records how many hours of usable sunlight land on each square of roof. That's the "sunshine hours" figure you see, and it's why two houses on the same street can score very differently.
Finally, Google fills the roof with standard 400 W panels, placing each one where it will generate the most over the year and ranking them from best to worst. For every panel count from a handful up to the maximum that fits, it reports the yearly energy the array would produce in kilowatt-hours. When you move the slider on this page, you're stepping through that list, and the roof drawing shows which panels come next.
We add one thing Google doesn't have: your electricity usage. That's what turns kilowatt-hours into dollars, and it's why the checker asks for your bill before it asks for your address.
- Roof area and segments – each face with its pitch and compass direction
- Sunshine hours per year – shade-aware, from Google's sun simulation
- Maximum panel count – how many 400 W panels physically fit
- Yearly output per panel count – kWh for every array size, best panels first
- Aerial roof image – with the chosen panels drawn on it
- Carbon factor – kg of CO₂ avoided per MWh on your local grid
How a panel layout becomes a dollar figure
The savings logic is the same one behind our solar calculator, so the two tools agree with each other. The difference is where the generation number comes from.
Generation
We take Google's yearly DC energy for your chosen panel count and multiply it by a 0.85 performance ratio to cover inverter losses, dirt, heat and wiring. The calculator instead uses system size × peak sun hours, which can't see your roof's shade.
Self-use and exports
By default we assume 35% of your solar is used at home and the rest is exported. Self-use is valued at your state's typical rate (32¢/kWh in Queensland) and exports at the typical feed-in tariff (6¢/kWh). Self-use can never exceed what your home actually consumes, so oversizing doesn't inflate the result.
Bill, payback and 25 years
Your bill before solar is your usage at that rate; after solar we subtract the savings. Lifetime savings assume flat prices over 25 years, which is deliberately conservative. Payback only appears when you enter a real quote, because we won't guess a price that won't match your actual install.
Why we ask for your bill, and how we look after it
A bill is the single most useful thing you can give a solar designer. It tells us how much electricity you actually used and over how many days, which means we can size a system to your home rather than to the postcode average. If you upload a PDF bill, we read the average daily usage, the total kilowatt-hours and the billing period straight off it and pre-fill the checker. If it's a photo, we keep it for the team and ask you to type the daily figure, which every retailer prints near the usage graph.
Bills contain personal details, so we treat them as sensitive from the first byte. The file is checked to make sure it really is a PDF or an image and is under 10 MB, then encrypted with a key that lives only on our server and stored in our database as ciphertext. It is never written to a public folder, never emailed as an attachment and never shared with anyone outside QVolt. If you don't go on to ask for a quote, the file deletes itself after 30 days. If you do, it stays with your enquiry so the team can prepare an accurate design, and only a logged-in QVolt team member can open it.
You never have to upload anything. Choose "Enter it myself" and type your quarterly bill amount or your daily usage instead. The result will be a little less precise, but it's still built on your roof rather than an average one.
Bill handling, in short
- PDF, JPG, PNG or WEBP, up to 10 MB, checked by content not just file name
- Encrypted at rest before it is stored; the key never leaves the server
- Deleted automatically after 30 days unless you request a quote
- Never shared, sold or used for marketing
- Only a logged-in QVolt team member can download it
- You can skip the upload and type your usage instead
What can change the number you see
The checker is a strong first look, not a design. These are the things we check on a real quote that the tool can't see.
Imagery age and quality
Google flags each area as high, medium or low quality and shows the imagery date under the roof photo. New roofs, extensions, removed trees and new neighbours won't be reflected until Google reflies the area.
Your export limit
Ergon Energy and Energex cap how much solar each home can push back into the grid, and on some streets the transformer is nearly full. If exports are limited, a battery or a larger self-use share matters more than extra panels. Our export checker looks your address up on the network's own capacity map.
Roof obstacles and electrical setup
Vents, skylights, aerials, hot water units and the condition of the roof itself all move panels around. Single or three-phase supply and your switchboard decide the inverter, which decides the practical maximum size.
How and when you use power
A home that runs the pool pump, dishwasher and air conditioning during the day self-consumes far more than one that's empty until 6 pm. Move the self-consumption slider in the full breakdown to see how much this changes the savings.
Solar panel checker, answered
What is the Google Solar API and where does the roof data come from?
The Solar API is a Google service built from aerial imagery and a 3D surface model of buildings. For each roof it publishes the roof segments (size, pitch and compass direction), the hours of usable sunshine per year, the maximum number of panels that fit and how much energy each panel count would produce. We query it for your address and draw the result on the aerial photo.
Why does the aerial photo of my roof look old?
Google's imagery date varies by area. Many Queensland suburbs use flights from 2016 to 2023, so a new roof, an extension or trees that have grown since won't show. The panel counts and sunshine figures are calculated from the same imagery, so if your roof has changed, treat the result as a guide and ask us to check it.
Is the panel layout what QVolt would actually install?
Not exactly. Google places identical 400 W panels in the sunniest positions first, without knowing about vents, skylights, aerials or your switchboard. A real design uses the panel model you choose, keeps sensible clearances and groups panels into strings for the inverter. It's usually close, but the layout on this page is a starting point rather than a plan.
How accurate is the savings figure?
As accurate as its inputs. Generation comes from Google's shade-aware yearly energy figure with a 0.85 performance ratio, and the dollar value uses your state's typical power price and feed-in tariff, the same numbers as our solar calculator. Your real tariff, how much power you use during the day and any export limit on your street will move the result. That's why the full breakdown lets you change self-consumption, add a battery and enter a real quote.
Do I have to upload a bill?
No. A bill gives the most accurate result because we read your actual kWh and billing period from it, but you can type in your quarterly bill amount or your average daily usage instead. Every bill shows average daily usage, usually next to the usage graph.
What happens to my bill after I upload it?
It is checked, encrypted with a key that never leaves our server and stored in our database. It's never shared, sold or used for anything other than your estimate. Unless you ask for a quote, it is deleted automatically after 30 days. Only a logged-in QVolt team member can open it, and only to prepare your quote.
Why don't you show a system price?
Because no two installs cost the same. Roof type, switchboard, phases, panel and inverter brands and access all change the price, and a number that doesn't match your real quote just causes confusion. Enter a fully installed quote from us or anyone else and the checker shows payback and 25-year return on that figure.
Does the checker work outside Queensland?
The roof analysis works anywhere in Australia that Google has Solar API coverage, which includes most capital cities and larger regional centres. The savings use state-based tariffs. QVolt installs in Queensland and northern New South Wales; if you're elsewhere, the numbers are still yours to take to a local installer.
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