Is solar and a battery worth it in WA?

What your solar exports earn

On the SWIS grid, Synergy's Distributed Energy Buyback Scheme (DEBS) pays for the solar you send back rather than use. It pays a higher rate for exports in the afternoon-to-evening peak window and a lower one the rest of the time, on a capped number of kilowatt-hours a day. That buyback is real money, and it's a big part of why solar on its own already stacks up for most Perth roofs.

Peak export rate (3pm–9pm)

10c/kWh

Off-peak export rate

2c/kWh

Daily export credited

up to 50 kWh

A1 rate you pay to import

about 33c/kWh

But look at the gap. You're paid a couple of cents for a kilowatt-hour exported at midday, then charged around 33 cents to buy that same energy back after sunset. Every unit you send out cheaply and buy back dearly is the economic doorway to a battery.

Why a battery, and when it earns its keep

A battery closes that gap. Instead of exporting your midday surplus for a few cents and buying it back at the full rate that evening, you store it and run your own home on it after the sun goes down. In Perth that evening block — roughly 3pm to 9pm — is when a typical household's demand is highest and when grid electricity costs the most.

So a battery's value is mostly self-consumption, not export. Every stored kilowatt-hour you use yourself is worth the ~33 cents you didn't pay Synergy, not the couple of cents you'd have earned sending it out. How big that prize is depends entirely on your usage shape: a home that's busy in the evening — cooking, air-conditioning, an EV on charge — captures far more of it than a home that sits empty until late. That is the single biggest variable in whether a battery is worth it, and it's the one only your own habits can answer.

What the WA Residential Battery Scheme changes

The single biggest recent shift in the maths is the WA Residential Battery Scheme. For Synergy customers it comes straight off the upfront price, which shortens payback more than any tariff tweak.

State rebate

$130/kWh, up to $1,300

Eligible capacity

5–10 kWh

Interest-free loan

up to $10,000

Loan income cap

household under $210,000

Federal small-scale technology certificates (STCs) stack on top and come off the installed price as well, but the federal amount tapers over time, so the combined figure moves — an installer's quote is where you see the exact number for your system and install date, not a headline. One condition worth knowing up front: the state rebate requires you to enrol in Synergy's Battery Rewards virtual power plant (VPP), covered next.

The VPP condition, in plain terms

Battery Rewards lets Synergy briefly draw on your battery during grid peaks in exchange for a credit. Enrolling is a condition of the state rebate.

Activation credit

70c/kWh discharged

Typical events a year

about 6–12

Maximum events a year

30

Contract term

2 years

Western Power: what to expect

Western Power is the distributor — the poles, wires and connection approval — separate from Synergy, who is the retailer that bills you. Any solar-and-battery system needs Western Power's sign-off, and since 1 May 2026 new systems fall into export tiers based on how the system is connected and monitored.

Basic (fixed) export limit

1.5 kW

Managed connection limit

Typically 3 kW or 5 kW

VPP participation

dynamic limit

Residential system cap

30 kVA

None of this is a reason to hesitate — it's routine, and a good installer handles the paperwork. But your export limit shapes what your solar can earn, so it's worth understanding before you size a system. Our guide to the May 2026 connection requirements goes through the detail.

How long does solar and a battery take to pay back?

As the sections above show, it turns mostly on how much of your own solar you use at home, and that differs from one household to the next. That is why we don't quote one payback for every home. Our size pages model it for two example households, and an installer can work it out from your bill.

See the 6.6 kW and 10 kW solar and battery pages for the modelled savings and payback at each size.

Does a time-of-use plan make sense with solar and a battery?

Often, if a battery covers your evening. Synergy's Midday Saver charges 8.85c/kWh from 9am to 3pm, 55.33c/kWh from 3pm to 9pm and 24.34c/kWh overnight, against 33.26c/kWh on the Home Plan (A1). It needs an advanced meter, and its supply charge is 132.78c a day against 119.24c, so a home buying little from the grid may do better on A1.

Is now a good time to buy, or should I wait?

Federal support steps down. The battery discount per kWh is set by the install date and next falls in Jan-Jun 2027, and the solar discount falls each 1 January until the scheme ends in 2030. So waiting means less support, not more. A well-sized system matters more than timing, and solar now with a battery later still works.

The 1 January 2027 step-down sets out the dates. This is general information about the schemes, not financial advice.

Worth it for whom

No honest page ends with “yes, always.” A battery is a good buy for some Perth homes, a marginal one for others, and a sensible thing to defer for plenty more. Here is roughly how the three cases break down.

A strong fit

You're home and using power in the evening — air-conditioning, a pool pump, an EV on charge — your bills already sting at peak, and your roof has room for enough panels to refill the battery each day. Self-consumption does the heavy lifting, the rebate shortens the payback, and the system earns steadily rather than on paper.

A weaker fit

Your usage is low, mostly daytime (the house is empty until late), or your roof is small or shaded. Here solar on its own already captures most of the benefit through self-consumption and DEBS exports, and a battery tends to add cost faster than it adds value. Solar first is often the sounder call.

Better to wait

Many homes are best served by putting solar in now, living with it for a season to learn their real usage shape, and adding storage once their evening load — and the scheme — clearly justify it. Nothing about the current rebate forces solar and a battery into a single purchase, and a battery bought to match a usage pattern you can actually see beats one sized on a guess.

Get a read on your own place

The four things above all turn on your home. Tell us a little about your usage and roof and we'll give you a personalised read, then match you with WA installers for the system you choose. We're the matchmaker, not the retailer — the installers quote and install; we don't sell systems ourselves.