WA's DEBS Feed-In Explained: The Two-Rate Solar Buyback

If you're on Synergy in WA and you've got (or you're weighing up) rooftop solar, the money you earn for exporting power comes through the Distributed Energy Buyback Scheme (DEBS). Unlike the old flat feed-in tariffs, DEBS pays you two very different rates depending on the time of day you export. That single design choice changes the maths on almost every solar and battery decision in the state — so it's worth understanding properly before anyone quotes you anything.

The two-rate structure, in plain numbers

DEBS is a time-of-use buyback. On Synergy in the South West Interconnected System (SWIS), the rates are:

Export period	Time	Buyback rate
Peak	3pm–9pm	10c per kWh
Off-peak	All other times	2c per kWh

The catch built into the design: the higher rate applies to roughly the first ~50 units (kWh) of export per day, and — critically — the 10c window sits in the late afternoon and evening, exactly when your solar panels are winding down or already off for the day. Most of a typical rooftop system's export happens in the middle of the day, when the rate is only 2c.

Why the timing matters more than the headline rate

It's easy to see "10c" and feel good about it. But your solar generation curve peaks around midday and fades before 3pm. So a standard export-heavy setup earns most of its buyback at the 2c off-peak rate, and only catches the 10c rate in the shoulder of the afternoon.

That flips the usual advice about solar. Under a flat feed-in tariff, exporting spare power was simply "free money". Under DEBS, exported midday power at 2c is worth far less than the power you avoid buying from the grid. On Synergy's Home Plan A1 or the Midday Saver time-of-use plan, the electricity you consume yourself is worth well more than 2c a unit — so self-consumption beats export by a wide margin during the day.

What this means in practice

• Run big loads — dishwasher, washing machine, pool pump, hot water — during daylight, so your own panels power them instead of exporting at 2c.
• Don't oversize a system purely to export more; the export earns the low rate.
• The 10c evening window rewards anyone who can shift export to the late afternoon — which almost always means storage.

Where a battery fits (and where it doesn't)

The two-rate design is genuinely battery-friendly. A battery lets you soak up cheap or self-generated midday solar and either use it in the evening (avoiding peak grid prices) or discharge some into the 3pm–9pm window to earn the 10c rate rather than the 2c one. That arbitrage is the whole logic of DEBS's structure.

WA also has real support for storage right now. The WA Residential Battery Scheme is open (expected to run to around 2027) with an indicative rebate in the range of $1,300–$3,800, and it stacks with the federal Cheaper Home Batteries program (a battery-STC discount, factor 6.8 per usable kWh for May–Dec 2026, stepping down roughly every six months). An optional no-interest loan of $2,001–$10,000 is available for households earning under $210k.

Some conditions to note before you get excited:

• The state rebate covers batteries with 5–10 kWh usable capacity.
• VPP participation is mandatory for the WA rebate — you're agreeing to let the battery be used as part of a virtual power plant.
• The battery must be installed on or after 1 July 2025.
• Exact dollar figures and eligibility shift — confirm the current numbers before committing.

The honest part: it still might not pay

Here's the beat nobody selling batteries will lead with. A battery earns its keep three ways under DEBS: avoiding peak grid purchases, capturing the 10c evening export, and (for the state rebate) VPP participation. But those returns are modest per kWh, and typical battery payback in our data sits around 8 years — sometimes longer if your evening usage is low or your household is out during peak.

If you're a low-usage household, or you're rarely home between 3pm and 9pm, the value of shifting energy into the peak window shrinks fast. In that case the cheaper, higher-return move is usually right-sizing your solar and simply shifting your daytime loads — no battery at all. Also worth flagging: WA has a low single-phase export limit (1.5 kW in our pack), so a huge export-oriented system can be constrained anyway, and WA is not part of the federal Solar Sharer free-power window that some eastern states get.

The right answer depends entirely on your load profile, your plan (A1 flat vs Midday Saver), and when you actually use power — not on a brochure average.

We don't sell panels, batteries or plans, and we don't take a cut from anyone who does. Our only job is to model your actual usage against DEBS's two rates and tell you the truth — even when the truth is "keep your current setup and just move your washing to lunchtime."

Figures in this guide are current at the date of publication and indicative only — rebate and certificate values change over time (federal battery certificates step down each January and July), and state schemes are amended often. Confirm the current numbers for your situation before you commit. This is general information, not personal financial advice.