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Solar Sharer stress test31 July 2026Evidence-led guide

Solar Sharer Offer Stress Test: Is Three Hours of Free Electricity Actually Worth It?

Three free hours can reduce a bill, but only when the household can use enough energy at midday to overcome the supply charge, the rates charged during the other 21 hours and any solar export value it gives up.

Check your break-even pointSee how it is modelled
3 hoursfree window each day
Up to 24 kWhfree-window allowance
5 regionsin the first-release scope

The useful question is not whether three hours of free electricity sounds attractive. It is how much electricity you can genuinely move into the window, what your current plan charges outside it, and whether solar, battery losses or an absent EV reduce the value.

The useful test

Start with the rates on your bill, then test how much load you can genuinely move into the free window. The calculator separates supply charges, outside-window usage, feed-in credit and battery-wear assumptions instead of hiding them in one headline number.

The direct answer

Most promising conditions

Enough flexible or naturally occurring daytime load, an EV that is home during the window, and a current plan whose outside-window rates are not materially better than the offer.

Conditions needing care

Low daytime demand, a solar system already covering the free period, a commuter EV that is away, or a battery that gives up export value while charging.

That is a decision framework, not a promise of savings. The final study will compare the same interval shapes under the Solar Sharer Offer and the regulated time-of-use DMO, then report the distribution across retained profiles rather than one synthetic home.

What the offer actually includes

The Solar Sharer Offer is an opt-in regulated offer for eligible residential customers with a smart meter in the initial NSW, South East Queensland and South Australia scope. The free period is fixed in displayed local time: 11:00–14:00 in NSW and South East Queensland, and 12:00–15:00 in South Australia. The daily free allowance is up to 24 kWh. Supply charges and usage outside the window still apply.

NSW and SE Queensland
11:00–14:00 local time
South Australia
12:00–15:00 local time
Policy facts represented by the first-release model
QuestionModel treatment
Daily allowanceFree-window imports are allocated against a 24 kWh local-calendar-day allowance.
Above the allowanceAny excess uses the configured above-cap rate; it is not silently treated as free.
Daylight savingIntervals are evaluated in the region's IANA time zone and the displayed local window does not move.
Solar exportsNet meter import and export are calculated after solar and device flows, so charging a battery can give up feed-in credit.

The calculation hidden by the word “free”

For a household comparison, the annual difference is the free-window import benefit minus the extra cost of imports outside the window, any supply-charge difference, lost feed-in credit, efficiency losses and an optional battery-wear allowance.

What is counted

  • Half-hourly household demand and solar shape
  • Net meter import and export
  • Local-day allowance reset
  • Supply charges and feed-in credits

What is not claimed

  • Observed Solar Sharer customer behaviour
  • A national average household
  • A timeless retailer ranking
  • Guaranteed personal savings

How the stress test works

The model uses historical Ausgrid/CSIRO Solar Home Electricity Data as a source of half-hourly shape, not as a claim about current national averages. Retained profiles are quality checked, rescaled to explicit scenario targets and simulated across five DMO distribution regions. Flexible load, EV availability, battery power limits, state of charge, round-trip efficiency and optional wear are explicit inputs.

The primary comparison is regulated Solar Sharer versus regulated time-of-use DMO. Current market plans are deliberately secondary because the AER Product Reference Data API exposes current plans and those plans can change after publication.

How to read the model

Look beyond “free”

The result depends on the whole day

A useful comparison combines free-window imports with the other 21 hours, supply charges, solar export value and device losses. That is why the calculator asks for your existing plan rather than presenting a universal verdict.

  • Free-window useHow much of the daily allowance you can physically capture.
  • Outside-window costWhat the offer charges when the free window closes.
  • Device effectsWhether an EV is home and whether a battery gives up export value.

Find your Solar Sharer break-even point

Enter the rates from your current bill and the current Solar Sharer fact sheet. This quick estimate uses a transparent representative-day model to show the direction and size of the difference. It is a range-finding tool, not personal advice.

Quick estimate

Use cents, not dollars. Fields marked with an asterisk are needed to calculate a comparison.

1
Your householdStart with your region and typical daily use, then add the devices or load you can shift.
Use an annual bill divided by 365 if that is easier.
Only count load that can realistically move into the free window.
Use usable capacity, not nameplate capacity.
Enter zero when the EV is usually away.
Shown separately; it is not a battery-health forecast.
2
Your current planUse the rates on your current bill. This is the baseline the offer must beat.
3
Solar Sharer offerEnter the offer's charges from the current retailer fact sheet.

Practical decision checklist

  1. Confirm smart-meter eligibility and the local free window.
  2. Record supply charge, outside-window rates and feed-in tariff.
  3. Estimate genuine shiftable daytime load, not theoretical appliance energy.
  4. Check whether the EV is home and whether the battery has headroom.
  5. Compare with your current plan, not only a regulated benchmark.
  6. Monitor actual bills after any plan change.

Where automation changes the result

Automation can make a suitable tariff easier to use consistently by tracking time windows, EV availability, battery state of charge and manual overrides. It cannot turn a poor tariff into a good one. See the battery cycle economics guide, battery wear estimator, ROI calculator, automation ROI examples and market insights for related decision tools. For market structure context, read Australian Home Energy 101 and the electricity volatility guide.

Limitations

This is a general model, not personal financial or energy advice. Tariffs, eligibility, meter treatment and device behaviour vary. The source load shapes are historical and rescaled; they are not nationally representative. Tariffs are checked and versioned at build time. No result represents observed Solar Sharer customer behaviour.

Frequently asked questions

Is Solar Sharer really free?
Only eligible free-window imports up to the daily allowance are free. Supply charges, outside-window usage and any above-cap rate still matter.
Do I need rooftop solar?
No. Solar Sharer can be relevant without rooftop solar, although a solar system may already cover some midday load and may create a feed-in opportunity cost when a battery charges.
Should I charge my EV or home battery first?
There is no universal answer. Direct EV charging avoids home-battery round-trip losses, while a battery may be useful when the EV is away. The full study compares those priorities explicitly.
What happens after 24 kWh?
The model applies the configured above-cap rate. The daily allowance resets at local midnight.
Does daylight saving change the free period?
The displayed customer window remains fixed in local time. The model evaluates each interval using the region time zone and local civil date.

Sources and methodology

Rates checked: 31 July 2026. Tariffs, eligibility and device behaviour can change, so confirm the current retailer fact sheet before switching.

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