DEBS strategy: how to maximise your solar export earnings in Perth

The Distributed Energy Buyback Scheme (DEBS) pays Perth solar households 10c/kWh for electricity exported between 3pm and 9pm, and 2c/kWh at every other time of day, including the 9am–3pm window when most rooftop solar actually generates. That's a five-to-one gap between the two rates, and it catches people out: the hours your panels work hardest are priced the lowest.

The real lever isn't chasing the 10c rate. Every kilowatt-hour you use directly, or store in a battery and use later, is worth 33.26c/kWh in avoided import, more than three times the best DEBS export rate. Get self-consumption right first. Then use timing to squeeze a bit more out of whatever you still export. Here's how to work with DEBS rather than against it.

DEBS at a glance:

• Evening peak export (3pm–9pm): 10c/kWh
• Off-peak export, including 9am–3pm: 2c/kWh
• Self-consumption on the A1 tariff: worth 33.26c/kWh in avoided import
• Daily export cap: 50kWh, combined peak and off-peak. Export beyond that earns nothing at all.

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Why does DEBS pay less for exports in the middle of the day?

Before DEBS launched in 2020, the Renewable Energy Buyback Scheme (REBS) paid every exported kilowatt-hour the same flat rate, no matter the time. DEBS replaced that with time-differentiated export pricing to reflect what the grid actually needs. Perth's rooftops are thickest with solar around midday, and by early-to-mid afternoon the grid is often oversupplied with it. Exports then aren't worth much to Synergy, so they're not worth much to you either.

The evening tells a different story. As the sun drops and household demand ramps up, ovens, air conditioners, televisions, the grid needs power from somewhere. Exports landing in the 3pm–9pm window earn five times more, because that's when the grid is short, not flush.

For the full mechanics of how DEBS is calculated and billed, see DEBS explained. If your system predates 2020, check how DEBS and REBS compare to confirm which scheme you're actually on.

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What does DEBS actually pay a typical Perth household?

Less than the headline rate suggests. A 6.6kW north-facing system peaks between 10am and 2pm, squarely inside the off-peak window. The 3pm–9pm peak window only opens once generation is already tapering off.

Typical generation by DEBS window (clear summer day, 6.6kW north-facing):

• 9am–12pm (off-peak): 15–20kWh
• 12pm–3pm (off-peak): 12–16kWh
• 3pm–6pm (peak): 4–8kWh
• 6pm–9pm (peak): 0–1kWh

Of the 30-plus kWh generated on a day like that, only around 8–9kWh falls inside the peak window, and the household usually consumes much of it in the late afternoon rather than exporting it.

Run a full year at that shape. A 6.6kW system exporting roughly 5,500kWh, split about 15% peak and 85% off-peak, earns (825kWh × 10c) + (4,675kWh × 2c) = $176 a year. That works out to an effective rate near 3.2c/kWh across all export, not the headline 10c. "Up to 10c/kWh" is a real number. It just applies to the slice of export landing in the 3pm to 9pm evening window.

The 15/85 split models a north-facing roof with no battery. West-facing panels, or a battery discharging into the evening, push more export into the 10c window and lift that effective rate.

Still on REBS? The same 5,500kWh profile earns 5,500 × 7.135c = $392 a year, roughly 2.2 times the DEBS figure. That's worth protecting. Upsizing your solar, replacing your inverter, or adding a battery can all trigger a permanent move to DEBS, so confirm any system change with Synergy first.

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What's the biggest lever if you don't have a battery?

Run your loads while the sun's up. Without a battery, self-consumption beats exporting under DEBS by a wide margin, at either rate.

Take a 2kWh dishwasher cycle. Run it at 11am, self-consuming solar directly, and you save 2 × 33.26c = 66.5c in avoided import. Export that same 2kWh instead (worth just 2c off-peak) and run the dishwasher later on grid power, and you earn 2 × 2c = 4c from the export but pay 2 × 33.26c = 66.5c for the import: a net loss of 62.5c.

Even timing that evening load to land inside the 3pm–9pm peak window, exporting the solar at 10c/kWh instead, only earns 20c: still a 46.5c loss against self-consuming at 11am. The gap between the two DEBS rates matters, but it's small next to the gap between exporting and using the power yourself.

Scaled up, the timing bonus stays modest too. On a system exporting around 20kWh a day, shifting all of that export from the 2c window to the 10c window is worth about $11.20 a week. Useful, but a fraction of what getting self-consumption right saves you outright.

Run washing machines, dishwashers, pool pumps and other flexible loads during daylight hours, whenever the sun's actually up. That holds whether it's 9am or 3pm.

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How does a battery change the strategy?

A battery gives you a third option: store midday solar instead of exporting or using it straight away, then release it when it's worth more.

1. Charge from solar during 9am–3pm. Exports in this window are only worth 2c/kWh, so there's little cost to filling the battery instead.
2. Discharge during the 3pm–9pm evening peak, replacing grid imports at 33.26c/kWh. This is the single biggest saving in the whole strategy, bigger than anything DEBS's export rates offer directly.
3. Once the battery's full, let any remaining solar export. If it's still generating into the 3pm–9pm window, common in a Perth summer, that surplus earns the 10c peak rate rather than the 2c you'd get earlier in the day.

Most hybrid inverters default to something close to this in their "self-consumption" or "time-of-use" mode. If yours has a manual schedule, check it's set to discharge across 3pm–9pm, not just at one fixed evening hour. For the settings themselves, see configuring your battery for maximum savings.

Battery charge reserve strategy

Starting each day with a low, or near-zero, minimum state of charge lets the battery absorb more solar during the 9am–3pm window. Because exports in that window are only worth 2c/kWh, there's little to lose by prioritising the battery over the grid.

Arrive at 9am with a full battery and that morning's solar spills straight to export at 2c/kWh instead. Not a big dollar loss on its own, but it's generation you paid for, sold at a token rate, when it could have gone into an evening discharge worth over ten times as much.

Set a minimum reserve of 10–20% overnight, let the battery fill from solar during the day, and discharge it through the evening. Not sure what size battery actually covers your evening load? Our sizing guide walks through the calculation.

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Do west-facing panels earn more DEBS income?

A little, but rarely enough to plan around. West-facing panels generate more between 2pm and 5pm, just as north-facing panels taper off, so some of that output lands inside the 3pm–5pm slice of the peak window.

The catch is total output. A pure west-facing array generates roughly 13% less energy a year than a north-facing one, and the extra peak-window generation usually doesn't cover that shortfall. If your roof genuinely gives you the choice, north still wins. West earns its place when roof geometry rules north out. West-facing solar in Perth works through when that trade-off pays, and solar orientation myths covers the rest.

One more reason not to chase peak export: if you're on Midday Saver, importing during the 3pm–9pm peak costs 55.33c/kWh. Using stored solar yourself in that window beats exporting it at 10c every time.

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Is it worth timing air conditioning around DEBS?

Air conditioning is Perth's biggest discretionary load, typically drawing somewhere in the 1.5–5kW range depending on the unit and how hard it's working. Under DEBS, the timing question isn't really about export. It's about which import rate you're avoiding.

Pre-cool in the early-to-mid afternoon, before 3pm, while solar is still doing the work. A 3kW air conditioner run for two hours at midday, powered directly by solar, only costs you the export you're giving up: 6kWh × 2c/kWh = 12c. Run that same 6kWh during the evening peak without a battery, importing from the grid, and it costs 6kWh × 33.26c/kWh = $2.00.

Cool the house down while the sun's doing the work, not before it starts. Pre-cooling on grid power before 9am pays the full import rate for no upside, since the window you'd be avoiding, 9am–3pm, is priced at only 2c/kWh anyway.

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Why is midday solar worth so little under DEBS?

The 2c/kWh rate applies everywhere outside the 3pm–9pm evening peak, and that includes the 9am–3pm window when most Perth rooftops generate the bulk of their solar. It's a genuine trap in the DEBS structure: the hours your panels work hardest are priced the lowest.

Don't confuse this with the Midday Saver tariff's "super off-peak" import rate, also 9am–3pm, but a completely different number: that's the cheap rate Synergy charges you for buying power, not what DEBS pays you for exporting it. Our Midday Saver guide covers that side separately.

There's also a daily ceiling. DEBS credits the first 50kWh of combined peak and off-peak export each day. Anything beyond that earns nothing at all, it isn't downgraded to the lower rate, it's simply uncredited. Most households never get close. A large system, 13.3kW or more, paired with a battery discharging heavily into the evening peak, is the kind of setup that can.

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How do you check your DEBS strategy is actually working?

Compare your Synergy bill's export breakdown against what you'd expect. The bill shows separate line items for peak export (the 3pm–9pm window) and off-peak export (everything else). If most of your credit is landing in the off-peak line, your battery isn't holding enough charge back for the evening, or your export is happening earlier than it should be.

Your inverter's monitoring app, Fronius SolarWeb, Sungrow iSolarCloud, Goodwe SEMS, whichever you've got, shows the daily generation curve. Check that your battery is actually discharging, or your solar is actually exporting, inside the 3pm–9pm window, not petering out by mid-afternoon.

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DEBS rewards evening exports over midday ones, but self-consumption beats both. Run flexible loads and air conditioning while the sun's up, size and time a battery to cover the 3pm–9pm evening peak, and treat the 10c rate as a bonus on genuine surplus, not the main event.