WA solar feed-in tariff history: how Perth went from 40c to 2c per kWh

In 2010, a Perth household exporting solar electricity to the grid received 40 cents per kilowatt-hour. In 2026, the standard export payment on the Renewable Energy Buyback Scheme (REBS) is 7.135 cents per kilowatt-hour — and on the Distributed Energy Buyback Scheme (DEBS) peak rate, it's 10 cents per kWh for three hours in the evening. Understanding how this happened matters for understanding why battery storage now makes economic sense when it previously didn't.

Timeline: WA solar feed-in tariff and export payments

2010–2020: Renewable Energy Buyback Scheme (REBS) at its highest

2010: REBS launched at approximately 40c/kWh. The scheme was designed to support early solar adoption at a time when residential solar cost $8–$12/kW installed. At 40c/kWh export rate, with electricity import rates around 21c/kWh, Perth households were paid substantially more to export than to consume solar.

2011–2013: The high FiT attracted rapid uptake. Synergy's cost of buying back solar at above-market rates created financial pressure. Many early adopters on 40c REBS locked in the rate for 10 years — those contracts ran through to approximately 2020–2023 depending on connection date.

2013: New REBS connections began receiving lower rates. The tariff stepped down for new entrants as the scheme's cost to Synergy became apparent.

2014–2017: Successive reductions for new connections as the economics of solar changed. System costs had fallen dramatically — a 5kW system that cost $20,000+ in 2010 could be installed for $7,000–$9,000 by 2016. The policy rationale for a high export subsidy weakened.

2020: REBS rate for new connections settled at approximately 7.135 cents per kWh. This is now the REBS rate — a flat rate regardless of time of export. Existing grandfathered customers at 40c/kWh began rolling off as their 10-year terms expired.

2021: DEBS introduced

In July 2021, the Western Australian Government introduced the Distributed Energy Buyback Scheme (DEBS) as an alternative to REBS for new solar connections.

DEBS structure:

• Peak rate: 10 cents per kWh — exports 3pm to 9pm
• Off-peak rate: 2 cents per kWh — exports all other hours

DEBS replaced REBS for new solar system connections (systems connected after 31 July 2021 are enrolled in DEBS, not REBS).

The significance:

• For households that export predominantly during off-peak (10am–3pm solar generation peak), DEBS off-peak at 2c/kWh is dramatically lower than REBS at 7.135c
• For households that can shift load or have battery storage that charges during the day and exports during the peak window, DEBS peak at 10c is marginally better than REBS flat at 7.135c

2021–2026: Battery economics change

Why low export rates change the calculus:

At the 2010 export rate (40c/kWh), selling solar electricity was more valuable than self-consuming it (avoiding a 21c import). Maximising system size and export was optimal.

At the 2026 DEBS off-peak rate (2c/kWh), the economics reverse:

• Self-consumed solar avoids 33.26c/kWh import (A1) or 24.34c/kWh off-peak import (Midday Saver)
• Exported solar earns 2c/kWh

Self-consumption is now 10–16 times more valuable than export. This completely restructures solar + battery economics:

• In 2010: battery storage made limited sense (the export rate was high)
• In 2026: battery storage makes sense because diverting daytime solar into battery (instead of exporting at 2c) and consuming from battery at night (instead of importing at 33c) has a spread of ~31c/kWh

Why export rates won't return to high levels

Understanding the underlying cause of export rate decline explains why a return to high rates is unlikely:

The value of exported solar to the grid:

Solar generation peaks 10am–2pm when household electricity demand is relatively low. When many households export simultaneously (the "noon solar glut"), the grid receives more electricity than it needs at that moment. The wholesale price of electricity at noon on a sunny Perth day can fall to zero or even negative values.

Synergy, as the retailer buying REBS exports, is effectively paying 7c for electricity it cannot sell at that moment without loss. At 40c, Synergy was paying far above wholesale value — a cross-subsidy supported by policy intent to kickstart the solar market.

DEBS peak rate rationale:

The 10c/kWh DEBS peak rate (3pm–9pm) reflects that the grid genuinely values solar+battery exports in the evening — when demand is high and solar generation has ended. The 2c off-peak rate reflects that midday solar exports have minimal grid value.

Future directions:

Some jurisdictions are moving toward time-varying export tariffs that more accurately reflect real-time grid value. A system that exports reliably into evening peak demand (via battery) is genuinely more valuable to the grid than one that exports randomly during midday. WA's DEBS already embeds this concept.

What this means for system sizing decisions in 2026

The low export rate changes optimal solar system sizing:

2010 era (40c export): Maximise panel area. Every kWh exported earned 40c. Oversizing made sense.

2026 (2c export, 33c import):

• Size for self-consumption: panels that generate more than you consume during daylight hours create exports at 2c — low return
• Adding battery storage changes this: excess solar charges battery (avoiding 2c export), battery discharges at night (avoiding 33c import)
• The optimal system is: enough panels to fill daily self-consumption + charge battery, plus battery sized for evening/overnight load

A 6.6kW panel array with a 10kWh battery fills most Perth households' daytime self-consumption and charges the battery. Systems significantly beyond this size have their excess export valued at only 2c/kWh.

REBS vs DEBS: which is better for existing customers?

Customers who connected before 31 July 2021 remain on REBS (7.135c flat) unless they switch. Switching to DEBS is permanent.

DEBS is better if:

• You have or plan to add battery storage that can shift energy to the 3pm–9pm peak export window
• You have significant evening export (e.g. DEBS peak window sees significant exports)
• Your household is home in the evenings and can shift loads to DEBS off-peak periods

REBS is better if:

• You have no battery and export predominantly during midday (REBS 7.135c > DEBS off-peak 2c)
• You're on an A1-equivalent tariff and don't plan to change

The transition from 40c to 2c/kWh export represents a fundamental shift in solar economics — from a policy-supported export premium to near-market-value energy trading. Battery storage is the response to this shift: self-consumption is now the dominant value driver, and battery makes self-consumption possible at night.