Perth solar feed-in tariffs: history, current rates, and what comes next

Perth households who installed solar before 2020 often have a very different feed-in arrangement than those installing today. Understanding how feed-in rates have changed — and why — helps you understand your current arrangement and what to expect from policy shifts.

The early days: the Renewable Energy Buyback Scheme (REBS)

REBS launched in WA in 2010 as a flat 7.135c/kWh feed-in credit for all excess solar generation exported to the grid. This rate was set for 10 years (2010–2020), providing certainty for early adopters.

REBS characteristics:

• Flat rate: 7.135c/kWh regardless of time of day
• Available to: Synergy customers in the SWIS network
• Period: 2010–2020
• Status: closed to new entrants (existing REBS participants continue until they upgrade their system)

REBS was generous by today's standards in terms of simplicity, but at 7.135c/kWh flat, REBS often earns less annually than the time-of-use DEBS for typical north-facing Perth systems — because most solar export occurs during the day when DEBS off-peak rate (2c) is lower than REBS (7.135c), but solar exported during 3–9pm peak earns 10c/kWh under DEBS, which is better.

The transition: DEBS (Distributed Energy Buyback Scheme)

DEBS launched 1 November 2020 for new solar customers. Instead of a flat rate, DEBS reflects the value of solar to the grid at different times:

| Time period | DEBS rate (from 2023) | |---|---| | Peak: 3pm–9pm (all days) | 10c/kWh | | Off-peak: 9pm–3pm (i.e., overnight and all day) | 2c/kWh |

Why time-varying rates? The WA grid has experienced increasing midday solar saturation. When thousands of Perth rooftop solar systems export simultaneously at noon, the grid has more power than it needs — the value of additional generation at noon is genuinely low. But between 3pm and 9pm, when solar drops off and household demand increases, solar exports are more valuable to the grid. DEBS was designed to reflect this economics.

Who gets DEBS:

• All new solar installations since 1 November 2020
• Customers upgrading an existing REBS system (upgrade triggers switch from REBS to DEBS)
• Households who had no previous feed-in arrangement and join the scheme

REBS vs DEBS: which earns more?

This depends on your solar system orientation and daily generation/export pattern:

A north-facing system (most Perth solar) exports most surplus during 9am–3pm off-peak hours. At DEBS off-peak (2c/kWh), this generates low export revenue. Under REBS (7.135c flat), the same export earns more.

Worked example (6.6kW north-facing system, summer day):

• Midday export (9am–3pm): 8kWh
• Afternoon export (3pm–6pm): 2kWh

| Scheme | Morning/midday export | Afternoon export | Total daily export income | |---|---|---|---| | REBS (7.135c flat) | 8 × 7.135 = 57c | 2 × 7.135 = 14c | 71c | | DEBS | 8 × 2c = 16c | 2 × 10c = 20c | 36c |

REBS earns approximately twice as much per day in this scenario. This is why REBS participants are often advised not to upgrade their system if preserving REBS is a priority — a system upgrade triggers a permanent switch to DEBS.

When DEBS earns more: For a household that has shifted consumption patterns to consume during 9am–3pm and only exports minimal surplus at midday, and instead exports significant power during 3–9pm (through west-facing panels, for instance), DEBS can earn more per kWh on those afternoon exports.

Feed-in tariff trajectory and what might change

The downward pressure on off-peak rates: DEBS off-peak (2c) is already low, reflecting the genuine oversupply problem on the SWIS during midday hours. The WA government has increased the off-peak rate from 2c to 10c at peak rather than raising the off-peak rate — because raising the off-peak rate would create perverse incentives to export at noon when the grid doesn't want it.

Future scenarios discussed publicly:

• Export limits tightening (Western Power has already reduced some export limits in inner suburbs)
• Negative pricing: in some Australian networks, wholesale electricity prices go negative at midday (too much solar) — retailers can potentially pass these through to generators including rooftop solar
• Virtual power plant (VPP) programs that compensate for controllable export during high-demand evening periods

Batteries and time-of-use export: A battery paired with Midday Saver can deliberately export at the 3–9pm peak window (DEBS 10c), by charging the battery from solar during the day and discharging to export during peak hours. This requires an inverter that supports time-based export scheduling — not all systems do this by default.

What your feed-in tariff means for your bill

For most Perth solar households on DEBS, the feed-in income is supplementary rather than the primary financial benefit. The main saving comes from self-consumption — solar generation replacing grid import at 33.26c/kWh (A1) or avoiding peak rates at 55.33c/kWh (Midday Saver). DEBS export credits are a secondary benefit.

If you're sizing a solar system or evaluating a battery, maximise self-consumption first and treat export credits as a bonus — don't size a system primarily to maximise export income at current DEBS rates.

REBS and DEBS rates apply only to Synergy customers in the SWIS network. Rates are set by the WA Economic Regulation Authority and WA Government and are subject to annual review.