The Queensland Competition Authority has confirmed in its draft 2026-27 determination that Ergon’s regional feed-in tariff drops from 8.66 c/kWh to 6.153 c/kWh on 1 July 2026. That is a 29% cut to the rate Mackay homes get paid for exporting excess solar back to the grid. At the same time, the federal STC rebate gets smaller again on 1 January 2027 (deeming period drops from 5 to 4 years), and the federal battery rebate steps down every six months from 1 May 2026.
If you are a Mackay homeowner sitting on a quote, you are right to ask: install now, or wait? Here is the honest answer with the numbers.
What is actually changing on 1 July 2026
Two things matter for Mackay:
- Ergon residential feed-in tariff drops from 8.66 c/kWh to 6.153 c/kWh (a 29% cut). This is set by the QCA, not Ergon, and applies to eligible regional Queensland customers on the standard contract.
- Tariff 11 usage rate is expected to soften slightly in QCA’s draft, but it stays around 32 c/kWh.
The gap between what you pay (around 32 c/kWh) and what you get paid for export (6.153 c/kWh) widens to roughly 26 cents. That gap is what makes self-consumption (and batteries) so much more valuable from July 2026 onwards.
The federal STC rebate is also winding down
In 2026 a Mackay home (Zone 2, factor 1.536, deeming 5 years, STC price approximately $38) gets roughly:
- 6.6 kW system: ~$1,900 off
- 10 kW system: ~$2,900 off
- 13 kW system: ~$3,800 off
From 1 January 2027 the deeming period drops to 4 years. The same systems then receive approximately:
- 6.6 kW: ~$1,540 (loss of about $360)
- 10 kW: ~$2,330 (loss of about $570)
- 13 kW: ~$3,040 (loss of about $760)
So should you install before or after 1 July 2026?
The short version: for almost every Mackay homeowner, installing in the first half of 2026 (before 1 July) gives a better dollar outcome than waiting.
Reasons to install BEFORE 1 July 2026
You lock in the 8.66 c/kWh feed-in tariff for the rest of the 2025-26 financial year. Four to six months of higher exports help payback in year one.
STC rebate is still at 2026 levels until 31 December. Installing in February versus February of the next year means a bigger upfront discount.
Battery rebate is at its highest until 30 April 2026. Under DCCEEW’s Cheaper Home Batteries Program, the STC Factor for batteries is 8.4 STCs per kWh before 1 May 2026 (around $319 per usable kWh at an STC price of $38), dropping to 6.8 STCs per kWh from 1 May 2026 (around $258 per usable kWh at the same STC price), with a new tiered structure applied at 100% for the first 14 kWh, 60% for 14 to 28 kWh, and 15% for 28 to 50 kWh.
You start saving on bills immediately. Every quarter you delay is a quarter of Ergon Tariff 11 bills you pay in full.
Reasons it does NOT actually matter much
If you size your system right and design for self-consumption (most of your power used during the day, or paired with a battery), the feed-in tariff drop hurts you less than you think. A well-sized 10 kW system on a Mackay family home with a battery will self-consume 60 to 80% of its output. The export portion is the smaller half of the equation.
A real Mackay example
Take a four bedroom home in Andergrove using around 24 kWh a day, with an annual power bill near $2,200.
Scenario A: 10 kW system installed June 2026 (before changes)
- System cost after STC rebate: roughly $9,500 to $11,500 installed
- Year one savings: around $2,000 (self-consumption) plus $300 to $400 (export at 8.66 c/kWh until 30 June 2026)
- Simple payback: 4 to 5 years
Scenario B: Same 10 kW system installed November 2026
- STC rebate still at 2026 levels, similar net cost
- Export entirely at 6.153 c/kWh from day one
- Year one savings: around $2,000 (self-consumption) plus $220 (export)
- Simple payback: 4.5 to 5.5 years
Scenario C: Same system installed February 2027
- Deeming dropped to 4 years, so STC rebate roughly $570 lower
- Export at 6.153 c/kWh
- You have already paid roughly $2,200 in full Ergon bills while waiting
- Payback worsens by 6 to 9 months
What about adding a battery?
The federal Cheaper Home Batteries rebate makes batteries much more attractive in 2026. A 10 kWh battery installed in April 2026 attracts roughly $3,190 off (at 8.4 STCs/kWh, STC price near $38). The same 10 kWh battery installed in June 2026 attracts approximately $2,580 (at 6.8 STCs/kWh). The same battery installed in January 2027 will be lower again as the STC Factor steps down every six months under the changes that took effect 1 May 2026.
If your design includes a battery, the urgency is even higher. Installing the solar plus battery package before 1 May 2026 captures the highest rebate tier on the battery side and the higher feed-in tariff on any temporary excess export.
Bottom line for Mackay homeowners
Install solar before 1 July 2026 if you can. Install solar plus battery before 1 May 2026 if you are going down that path. If life gets in the way and you install in late 2026 or 2027, you are still going to save money. You just lose the easy first year wins.
Next Phase Solar runs honest assessments based on your actual Ergon bills, your roof, and your routine. Book a free solar assessment at /quote and we will model the numbers for your address in Bucasia, Andergrove, Slade Point, Sarina or anywhere across the Mackay region.
