Higher network charges could threaten battery value: what Perth owners should know

What's being proposed

The AEMC draft proposes shifting more of the cost of maintaining the electricity network from variable (per-kWh) charges to fixed (daily) charges. Under the current model, households that use less grid electricity — including solar and battery owners — pay lower network charges because they consume fewer kilowatt-hours. A flat fixed fee would change this dynamic.

Analysis suggests a flat fixed fee would raise bills most for energy-efficient households. In some scenarios it would also cut the value of the federal battery rebate, because it shrinks the per-kWh savings a battery delivers.

How batteries save money today

Battery savings come from two things. The first is self-consumption: storing solar through the day and using it at night, instead of buying grid electricity at 30–35c/kWh. The more per-kWh consumption you displace, the more you save. The second is export optimisation: sending stored solar to the grid during peak-value windows, such as the DEBS 3–9pm window at 10c/kWh, rather than during the midday solar glut when export rates are lowest.

If fixed charges rise while per-kWh charges fall, the first of these (self-consumption) is worth less. You save fewer cents per kWh displaced, even though you're still avoiding the same volume of grid consumption.

What this means for Perth

Western Australia operates its own electricity market (the WEM) separate from the NEM. This means the AEMC proposal would not directly change Synergy or Western Power pricing structures. However, there are reasons to pay attention:

• Regulatory precedent: Changes in the NEM often influence policy thinking in WA. If higher fixed charges prove workable in eastern states, WA regulators may consider similar approaches.
• Already partially in play: Synergy's existing tariff structure already includes a fixed daily supply charge (~$1.16/day). Any increase to this component would reduce the relative value of per-kWh savings from batteries.
• VPP value unaffected: Virtual Power Plant earnings (like Synergy Battery Rewards) are paid per-kWh and would not be reduced by changes to fixed network charges. This makes VPP participation even more important for maximising battery value.

Silver linings for battery owners

Even in a higher fixed-charge scenario, batteries retain significant value:

• Blackout protection: No network charge change affects the value of keeping your home powered during outages
• VPP earnings: Grid services payments are independent of network charge structures and may actually increase as more batteries join the grid
• Peak avoidance: Time-of-use tariffs still reward shifting consumption away from peak periods — batteries excel at this
• Energy independence: Reducing reliance on the grid has intrinsic value beyond pure economics, especially as electricity prices continue to rise

What you can do

For homeowners considering a battery now, the proposal shouldn't change your decision — it's a draft, it applies to the NEM (not WA), and current rebates are at their highest levels. If anything, locking in a battery now while per-kWh savings are maximised is the prudent approach.

For existing battery owners, maximise your system's value by:

• Joining a VPP program if you haven't already
• Optimising your time-of-use settings to maximise peak avoidance
• Maximising self-consumption by running high-energy appliances during solar hours