What Can Solar Export Data Be Used For ?

Uses for Solar Export Data — From Battery Sizing to Deciding on More Solar Panels

Last Updated: 2026-08-19

Key Takeaways

What can solar export data be used for ? It is a measured historical record of the surplus solar your home sent to the grid. That record supports decisions about batteries, extra panels, and your bill.
The main uses for solar export data are sizing a battery, judging whether to add panels, checking a feed-in credit, and tracking output over time.
Solar export data for battery sizing matters because your spare export sets the ceiling on what a battery could capture.
How much spare solar export do I have ? Your own recorded export answers that for your address. No rule of thumb replaces the measurement.
Am I exporting enough solar power to charge a battery ? Compare your recorded export against the capacity you have in mind, season by season.
Do I need more solar panels for a battery ? Where your spare export is small relative to the battery you want, adding panels increases the surplus available to charge it.

What Solar Export Data Actually Records

Solar export data is a measured historical record. It counts the solar electricity that left your property because your home was not using it at that moment.

Your smart meter records that flow on its own register, called B1. The B1 total is a real recorded quantity for your address, across every half hour of the period your file covers.

What your export figure counts	What it leaves out
Solar electricity your meter recorded flowing out to the grid.	The share of your solar the house used as the panels made it.
The surplus a battery would have had available to capture.	Your total solar yield, which is that surplus plus the share used on site.

The share your home uses at the time of generation is called self-consumption. The meter at your connection point cannot measure self-consumption, because that energy never crosses the connection point.

Where Your Own Export Figure Comes From

Your distributor or your retailer supplies it, usually as a NEM12 CSV file covering a year or more. For step-by-step instructions, see our guide on how to download your smart meter data.
The export figure sits inside that file. For step-by-step instructions on pulling it out, see our guide on how to extract solar export data from NEM12.
Your file names each register by a code. For what those codes mean, see our guide on how to interpret your smart meter data.

Solar Export Data for Battery Sizing

A home battery stores energy that would otherwise have left your property. Your spare export therefore bounds how much a battery could usefully capture.

A home with little spare export has little for a battery to capture, because most of its solar already goes into the house as it is generated.
A home exporting a large share of its generation has more surplus for a battery to work with, and usually more evening import to displace.
Timing counts as well as volume. A concentrated midday burst is easier to capture than the same total spread thinly across daylight hours.
Season counts in a cool climate. A home in Ballarat exports far less in July than in January, and July is usually when evening demand is heaviest.

Your spare export sets the ceiling on what a battery could capture. The capacity worth buying also depends mainly on your evening usage, the installed price, and any rebate you qualify for.

Try our NEM12 Solar-Export Battery-Sizer Tool

Turning that record into a capacity figure is a calculation on your own numbers. Our NEM12 Solar-Export Battery-Sizer reads a smart meter data file in your browser, and reports how much export was actually available to charge a battery.

For background on the wider retrofit question, see our info guide on whether to add a battery to an existing solar power system.

Do I Need More Solar Panels for a Battery ?

Where your spare export is small relative to the battery size you want, adding panels increases the surplus available to charge it. That relationship is physical, and it holds for any home.

Whether panels are the better spend for your household is a separate question, and your own figures drive the answer.

What moves the answer for a particular home

The size of the gap: how far your current spare export sits below the capacity you are considering.
When your household uses power: a home occupied through the day self-consumes more and exports less.
What each option costs: you buy panels and storage separately, at separate prices.
What your roof allows: available roof area and orientation both limit what an installer can add.

An installer builds a quote from your export history, your evening load, and your site. Arriving with your own export figures makes that conversation shorter.

Other Everyday Uses for Solar Export Data

The same export figure also answers several smaller questions around the house.

Checking the feed-in credit on a bill: compare your recorded export for the billing period against the units your retailer credited, after matching the two date ranges. Our guide on how to interpret your electricity bill covers where that credit appears.
Tracking export across a year: a drop against the same months last year can point to new shading, soiling, or a fault worth investigating.
Feeding a community platform: sites accept exported figures, which lets you compare your system against similar ones nearby.
Weighing a virtual power plant offer: your export volume is one input into what such a scheme is worth to you. Our info guide on what a virtual power plant is explains what you trade away.
Comparing electricity plans: a plan's feed-in rate is worth more to a household exporting a large surplus than to one exporting very little.

Where to Go Next With Your Export Figure

If you do not yet hold your data, start with the file. Our guides on working with smart meter interval data cover downloading it, reading it, and charting it.

If you already hold the file, a browser tool will read it for you. Our NEM12 Smart Meter Data Analyzer charts import and export together, and the full set of free online tools covers the other common jobs.

Try our NEM12 Smart Meter Data Analyzer Tool

When an Energy Assessment Helps With Your Export Data

Your export figure answers one question: what surplus exists at your address. An energy assessment sets that figure beside the rest of your household picture.

What an assessor reads alongside your export data

Your import as well as your export: what you draw from the grid after dark decides how much stored energy your home could use.
Your tariff: the price you pay at each time of day changes what a stored unit of energy is worth to you.
Your evening load: the appliances that run after sunset set the size of the gap a battery would fill.
Any quotes you already hold: an assessor can read a quoted capacity against your own recorded export.

An energy assessment covers the whole-home picture, and your export data is one part of it. An independent assessor works from the figures your own meter recorded.

If you would rather have a professional turn all of this into a clear, costed plan for your home, find out more about how our Energy Assessments can help you.

Frequently Asked Questions

What does the B1 register on my smart meter record ? B1 is always Solar Export — the electricity your meter records as flowing out to the grid, in kWh.
Is solar export data measured or estimated ? It is a direct measured historical record of the surplus solar your site sent to the grid.
Does my export figure show my total solar generation ? No. It counts exported surplus only, and the meter at your connection point cannot measure the share of solar your home used on site.
How much spare solar export do I have ? Your own recorded export over a full twelve months answers that for your address. A published average for other households does not.
Am I exporting enough solar power to charge a battery ? Compare your recorded export against the capacity you have in mind, month by month. Your own figures decide it for your home.
Why does solar export data matter for battery sizing ? Your spare export bounds how much a battery could usefully capture, because a battery can only store energy that would otherwise have left the property.
Do I need more solar panels for a battery ? Only where your spare export is small relative to the battery you want. Adding panels then increases the surplus available to charge it.
Can I use solar export data to check my feed-in credit ? Compare your recorded export for a billing period against the exported units your retailer credited, once the date ranges match.
Can solar export data show that my system output has dropped ? Compare your export month by month against the same months a year earlier. A sustained drop can point to new shading, soiling, or a fault worth investigating.
Can I share my export figures on a community comparison platform ? Some community platforms accept exported figures, which lets you compare your system against similar ones nearby.
How does my export data help me judge a virtual power plant offer ? Your recorded export volume is one input into what such a scheme is worth to you. The offer's own terms and your battery capacity are others.
Does my export data help me compare electricity plans ? A plan's feed-in rate is worth more to a household exporting a large surplus than to one exporting very little. Your recorded export shows which case applies to you.
Does solar export vary by season in a cool climate ? A home in the Victorian Central Highlands exports far less in July than in January. Winter is also usually when evening demand is heaviest.
What is self-consumption ? Self-consumption is the share of your solar generation that your home uses on site rather than sending to the grid.
Where do I get my solar export data ? Your distributor or your retailer supplies it, usually as a NEM12 CSV file. See our guide on how to download your smart meter data.
Can solar export data tell me which battery brand to buy ? No. It shows what surplus exists to capture, and product choice turns mainly on warranty, price, installer support, and compatibility with your inverter.
Does a low feed-in tariff make my export data less useful ? The rate your retailer pays changes what an exported unit earns. The recorded volume remains the measurement that battery and panel decisions rest on.

Try our NEM12 Solar-Export Battery-Sizer Tool

Glossary

B1: In the NEM12 Format, the Meter Register code for Solar Export — electricity generated on site and fed back to the grid, typically measured in kWh.
kW: KiloWatt — the standard unit of (Electrical) Power: 1,000 Watts of Power used continuously for one hour is equivalent to 1000 Watt-Hours or 1 KiloWatt-Hour of Energy. Power is not an Amount of Energy but a Rate of Energy Transfer. See also: kWh.
kWh: KiloWatt-Hour — the standard unit of (Electrical) Energy: 1,000 Watts of Power used continuously for one hour is equivalent to 1000 Watt-Hours or 1 KiloWatt-Hour. NEM12 CSV records Electricity Use in kWh. See also: kW.
NEM12: The AEMO file format (version 12) for exchanging Interval Data from Smart Meters across the Australian National Electricity Market (NEM). NEM12 Format records the Amount of Energy per Time Interval in kWh. And also other types of data, using specific types of labelled rows or records (100, 200, 300, 400, 900) to record different types of data. This makes it a 'Semi-Structured' 'Non-Tabular' Format. See also: AEMO, NEM, kWh, Semi-Structured, Non-Tabular.
NEM12 CSV: A NEM12 File stored as comma-separated values — the form most DNSP and retailer portals distribute. See also: NEM12, CSV.
Self-Consumption: The share of the electricity generated by your own solar panels that your household uses on site, rather than exporting it to the grid.
Smart Meter Data: Electricity import and export readings recorded by a digital interval meter at regular intervals. In Australia, typically supplied in NEM12 CSV Format with 30 Minute Intervals. See also: NEM12 CSV.
Solar Feed-in Tariff (FiT): The credit paid (in cents per kWh) by your Electricity Retailer for solar electricity you export to the grid (B1 Meter Register). In Victoria, a minimum rate was historically set annually by the Essential Services Commission (ESC). However, since July 2025, the ESC no longer sets a minimum, and Electricity Retailers are free to pay a Market Rate.

Try our NEM12 Solar-Export Battery-Sizer Tool