The instinct that is usually right
Ask anyone with a big rooftop solar system what to look for in an electricity plan and you will hear the same answer: the highest feed-in tariff you can get. When you are exporting thousands of kilowatt-hours a year, every extra cent per kWh is real money. If you export 5,800 kWh a year, the gap between a 3c and a 10c feed-in tariff is over $400 a year, bigger than the difference between most plans usage rates.
For a solar-only home, that instinct is correct. Chasing the best feed-in is exactly the right move. It stays right up until you install a battery, and then it flips, and most people never notice.
What a battery quietly changes
A home battery exists to keep your own solar instead of selling it. Power that used to flow to the grid at a few cents now charges the battery and runs your house that evening, offsetting electricity you would otherwise buy at 30 to 60 cents. Avoiding a 40c import beats earning a 10c export every single time.
The knock-on effect is the important part: your exports collapse, and with them the value of any feed-in tariff, no matter how high. You simply are not sending much to the grid to be paid for. A plan chosen for its generous feed-in now delivers almost none of that promised value.
A worked example
Take a Sydney home on the Ausgrid network: strong solar, exporting about 495 kWh a month, and a newly installed 30 kWh battery. Re-cost every plan on that usage and the battery self-consumes about 446 kWh a month of solar that used to be exported, so the annual feed-in credit does not shrink, it vanishes, from about $175 to zero.
The bottom line moves just as sharply. The best plan without the battery costs about $2,165 a year; with the battery modelled, the best plan costs about $636 a year, because the usage still bought from the grid has collapsed. The winning plan is not the one with the best feed-in. It is the one that prices the small remaining import cheaply.
These are illustrative figures for a worked example, not a specific customer’s bill. Your own numbers depend on your usage, solar, battery size and how it is configured, which is exactly why a rule of thumb is the wrong tool here.
What actually matters once you have a battery
When your usage charge falls from roughly $1,900 to around $110 a year, the things that used to be rounding errors become the whole game. In rough priority order:
- A low daily supply charge. This fixed cost does not move when your usage drops, so it becomes the largest slice of your bill, arguably the single most important number for a battery home.
- Cheap rates on the little you still import. After the battery covers your evening peak, most of your remaining grid use is off-peak or overnight, so a low off-peak (or EV) rate on a time-of-use plan matters far more than a low peak rate.
- Feed-in tariff, almost last. You export so little now that even a headline feed-in rate barely registers. Nice to have, not worth optimising for.
Why the highest-supply plan can still win
For our Sydney household, the winning plan actually had the highest supply charge on the shortlist. It just paired that with a rock-bottom off-peak rate that their small overnight import sat neatly inside, and on the total that beat every low-supply plan. It looks wrong at a glance and is correct on the maths, which is precisely why you should compare on the total cost for your real, battery-adjusted usage rather than on any single rate.
The honest caveats
A battery never perfectly times every peak. On cloudy days or big-usage evenings some import still lands at expensive peak rates, so a plan with a cheap off-peak but a brutal peak rate carries a little risk. It also depends on sizing: a battery too small for your solar still leaves real export on the table, where feed-in keeps mattering. See how to size a solar and battery system and whether a home battery is worth it for the trade-offs. The point is not to ignore feed-in, it is to let your actual, battery-adjusted usage decide, not a rule of thumb.
Frequently asked questions
Should I still get the highest feed-in tariff if I have a battery?
Usually not. A battery self-consumes most of the solar you used to export, so a high feed-in tariff applies to very little energy and earns you little. A low daily supply charge and cheap rates on the power you still import matter far more.
Does a battery reduce how much solar I export?
Yes, often dramatically. The battery stores your daytime surplus to run the house that evening instead of selling it to the grid, so your exports can fall close to zero. In a worked example, a 30 kWh battery cut about 446 kWh a month of export down to almost nothing.
Why did the recommended plan change after I added my battery?
Because a battery changes your usage profile: it slashes what you import at peak and nearly eliminates your export. Once that happens, the plan that is cheapest for you is a different one, and any tool that does not re-cost plans on your battery-adjusted usage will point you at the wrong plan. EnergySorted re-costs the whole market on your real, battery-adjusted usage.
What should a battery owner look for in an electricity plan?
In rough order: a low daily supply charge, cheap rates on the small amount you still import (usually off-peak or overnight), and only then the feed-in tariff. When your usage charge collapses, the fixed supply charge becomes the biggest lever.
Can a plan with a high supply charge still be the cheapest for me?
Yes. If your battery leaves you buying only a little power, a plan can pair a higher supply charge with a very cheap off-peak rate and still win on the total. That is why you should compare the whole cost on your real usage rather than judging by a single number.
What type of tariff suits a home battery best?
Usually a time-of-use tariff with a cheap off-peak or overnight window, because the little you still import tends to happen overnight after the battery has covered your evening. Some EV or dedicated off-peak plans do this especially well, see the best EV electricity plans.
Does my battery size change the answer?
It does. A battery that is small relative to your solar still leaves real surplus to export, where a good feed-in keeps mattering. A large battery soaks up nearly all your export, making feed-in almost irrelevant. See how to size a solar and battery system to understand your own position.
So should I ignore feed-in tariffs completely?
No. Feed-in still matters for any surplus your battery cannot store, and it matters a lot if you do not have a battery yet. The mistake is optimising your whole plan choice around it once a battery has cut your exports to a trickle. Let your actual usage decide.
Without a battery, is chasing the highest feed-in still smart?
Yes. A solar-only home that exports thousands of kWh a year can gain hundreds of dollars from a better feed-in rate, so for that household it is one of the most important numbers. The advice flips only once a battery starts consuming that export itself.
How do I actually compare plans with my battery in the mix?
Tell the tool you have a battery and let it re-cost the market on your real usage. EnergySorted models self-consumption and peak-shifting, so the plan it recommends is the one genuinely cheapest for your setup. Compare your plans on your real usage rather than trusting a rule of thumb.