WA solar & battery rebates are changing in 2026 — what to do before they drop

Three separate rebate changes hit in 2026, and each one reduces what you get back. If you've been sitting on the fence about solar or batteries, the next few months are the best window you'll have.

Change 1: Federal STCs dropped in January 2026

Small-scale Technology Certificates (STCs) — the federal rebate applied at point of sale — decreased on 1 January 2026 as they do every year. The deeming period shortened by one year, meaning fewer certificates per system.

For a 6.6 kW solar system in Perth (Zone 3), the STC rebate went from roughly $2,155 in 2025 to about $1,796 in 2026. That's around $360 less. Not catastrophic, but the reductions compound annually until the scheme ends in 2030.

| System Size | 2025 STC Value | 2026 STC Value | Reduction | |---|---|---|---| | 5 kW | ~$1,636 | ~$1,357 | -$279 | | 6.6 kW | ~$2,155 | ~$1,796 | -$359 | | 10 kW | ~$3,272 | ~$2,753 | -$519 | | 13.2 kW | ~$4,349 | ~$3,631 | -$718 |

Every year you wait, the deeming period shortens by another year — that's roughly a 17% cut from 2025 to 2026, and the bite gets bigger as 2030 approaches. By 2028, a 6.6 kW system will get about $700 less in STCs than it does in 2026.

Change 2: Federal battery rebate restructured on 1 May 2026

This is the big one. The federal Cheaper Home Batteries Program (CHBP) moved from a flat per-kWh rebate to a tiered system on 1 May 2026.

Pre-1 May 2026 rates (legacy):

• 8.4 STCs per usable kWh (all capacity treated equally)
• At ~$37/certificate = roughly $311/kWh rebate
• 10 kWh battery = ~$3,100 rebate

Current framework (since 1 May 2026):

• First 14 kWh: ~$243/kWh
• 15-28 kWh: ~$146/kWh
• 29-50 kWh: ~$36/kWh

For a standard 10 kWh battery, that's roughly $2,430 in federal rebate — still generous, but the per-kWh rate steps down further each year as the deeming factor reduces.

For larger batteries (20 kWh+), the taper bites harder: a 20 kWh system now receives roughly $4,290 versus the $6,200 it would have received under the pre-May rates.

Bottom line: Right-sizing the battery to actual household needs has the biggest impact on rebate value under the current framework.

Change 3: WA state battery rebate — new caps

The WA Residential Battery Scheme changed on 4 June 2025. The current structure:

• Synergy area (Perth metro / SWIS): $130/kWh, up to $1,300 (10 kWh cap)
• Interest-free loans: Up to $10,000 available for eligible households

The previous scheme offered $200/kWh up to $2,500 for all Synergy customers. The restructured scheme gives Perth metro $130/kWh (max $1,300). For a 10 kWh battery in Perth, you're getting $1,300 instead of the old $2,000 — a $700 reduction.

The interest-free loan component is new and potentially more valuable than the subsidy itself for households that would otherwise finance through a personal loan at 6-8%.

The combined picture

Stack all three and here's what a 10 kWh battery install looks like under the current framework versus the legacy pre-1 May 2026 rates:

| Component | Pre-1 May 2026 | Current (since 1 May) | |---|---|---| | Installed cost | ~$10,000 | ~$10,000 | | Federal battery STCs | -$3,100 | -$2,430 | | WA state rebate | -$1,300 | -$1,300 | | Your net cost | $5,600 | $6,270 |

The gap is roughly $670 for a 10 kWh system; for solar + battery combined the spread is wider because solar STCs continue stepping down annually too.

What's driving the steady demand

The CHBP was so popular in 2025 that installations blew past forecasts. Some brands — Sigenergy, GoodWe, BYD, Sungrow — had supply shortages. Tesla and Enphase were easier to source.

Forecasts suggest 75,000 battery installations nationally in 2026 (down from the 2025 rush). The pre-May surge in Q1-Q2 left most Perth installers with 4-6 week waitlists for popular battery models, and demand has stayed elevated under the new framework.

WA's inverter rules — in force alongside the rebate changes

Separate from rebates, Western Power's inverter connection rules also activated on 1 May 2026. Under the current framework:

• Aggregate inverter capacity is 30 kW under standard connections (up from 5 kW pre-May 2026)
• All new inverters support remote disconnection/reconnection
• Systems that don't meet the requirements have exports capped at 1.5 kW

This is good news for larger systems — 10-13 kW inverters are now standard connections without expensive network upgrades. But every new inverter must comply with the AS4777 standard configured for Australia Region B.

When comparing quotes, confirm with your installer that the inverter is on the Synergy SSL and configured for Australia Region B settings.

What we'd do

If we were a Perth household considering solar or batteries under the current framework:

1. Solar only: Order now. STCs continue to step down annually until 2030, and panel prices may rise as Chinese export subsidies are wound back.
2. Battery only (with existing solar): Right-size the battery — capacity tapers above 14 kWh shrink the per-kWh rebate, so a well-matched 10-13 kWh system often beats an oversized one for ROI.
3. Solar + battery together: Combined rebates total roughly $3,700 for a typical 10 kWh system after federal taper + WA state rebate. Stack DEBS + Battery Rewards on top.
4. On the fence: Run the numbers in our Savings Planner with current rebate levels. If payback is under 7 years, it's a go.

Related reading

• Home Batteries in WA — the honest ROI picture — Brand comparisons, degradation data, and when batteries make financial sense.
• WA Rebates & Incentives Guide — Full breakdown of every available program.

Check your specific numbers: Our Savings Planner uses current rebate rates and your actual postcode to calculate what you'd save. Takes 60 seconds.