System Size Is Only Half the Equation
A well-designed solar and battery system is the foundation. But how much you actually save depends heavily on how you use it. This guide shows you how to maximise your solar savings, whatever system you already have.
Perth has some of the best solar irradiance in the world, and some of the least generous export rates. The Synergy grid pays as little as 2 cents per kWh for electricity you export outside peak hours. Your electricity retailer charges you 33 cents or more to buy it back. That gap is where the savings opportunity lives. The more of your solar generation you consume directly or store in a battery, the less electricity you buy from the grid at full retail price.
This guide covers the practical strategies that make the biggest difference to your bill. These are timing your appliances, tuning your battery settings, choosing the right Synergy tariff, and understanding what happens with export payments.
Understand Your Generation Curve First
Before optimising anything, it helps to understand when your system actually generates. In Perth, a north-facing system typically follows this pattern:
- Generation begins: around 7am to 8am depending on season, as the sun clears the horizon and panels start producing.
- Peak output window: roughly 9am to 3pm, with maximum output around solar noon (12pm to 1pm).
- Generation falls away: from 3pm onwards as the sun angle drops. Most systems are producing very little by 5pm to 6pm.
- No generation: overnight. Your home draws entirely from the battery (if you have one) or the grid.
This curve shifts with the seasons. Summer days are longer and hotter. Generation peaks earlier and higher. But panel output drops slightly on very hot days due to heat. Winter days are shorter. Generation is lower in total. The peak window is narrower.
Your monitoring app shows this curve in real time and historically. Checking it regularly, especially in the first few months, gives you a clear picture of when to concentrate your appliance use.
Self-Consumption: Where the Real Savings Are
The most powerful savings lever available to Perth solar owners is self-consumption. This means using your own generated electricity instead of exporting it or buying from the grid.
The maths are simple. Every kilowatt-hour you use directly from your solar panels during the day avoids buying that unit at the retail rate. That rate currently sits around 33 cents per kWh on a standard Synergy tariff. If you export that same unit instead, you receive between 2 cents (off-peak) and 10 cents (peak hours, 3pm to 9pm) under DEBS. This only applies if your inverter is 5kW or under. For larger inverters, there is no export payment at all.
The numbers strongly favour using your generation rather than exporting it. A battery takes this further. It stores what you cannot use during the day and supplies it in the evening when generation has stopped.
Appliance Timing: What to Run and When
Shifting high-draw appliances into your peak generation window, roughly 9am to 3pm, is the single biggest habit change most households can make.
Not every appliance can be shifted every day, and that is fine. Focus on the two or three highest-draw appliances in your household. Timing them consistently makes a real difference to your bill.
Battery Optimisation: Getting the Settings Right
A battery is most valuable when it is set up to match your household’s actual usage pattern. The default settings on most batteries are a reasonable starting point. But a few changes can improve performance a lot.
Charge mode: solar-only vs time-of-use
Most hybrid inverters offer a choice between two charge modes. Solar-only charging means the battery charges only from excess solar generation. Time-of-use or scheduled charging means the battery can also charge from the grid during off-peak periods. For most Perth households on the standard Synergy A1 tariff, solar-only charging is the right setting. There are no low-cost off-peak grid rates to use on that tariff. If you are on a time-of-use tariff with low overnight rates, scheduled charging may make sense.
Minimum reserve (backup reserve)
Most battery systems let you set a minimum state of charge. This is a share of battery capacity that is held back and only used during a grid outage. A higher reserve means more protection during a blackout. But it leaves less capacity for daily cycling. For most households, a reserve of 10% to 20% is a reasonable balance between backup protection and daily savings. If blackout protection is a priority, set the reserve higher. If maximising bill savings is the goal, keep it lower.
Evening discharge strategy
The battery’s job in the evening is to supply your home’s load so you are not buying from the grid. Most battery systems handle this automatically. The battery discharges as your home draws power after solar generation has stopped. Where you have control is in managing the minimum reserve setting. Understanding how much capacity you actually need to get through the night, based on your evening and overnight use, helps too.
Monitoring your daily cycle
Check your monitoring app now and then. See whether the battery reaches near full charge during the day — a sign your system sizing is well matched to your generation. Also check whether it runs low before morning — a sign your evening use may be higher than expected, or that your battery capacity could be increased. A battery that regularly runs flat by midnight is not delivering its full overnight value.
DEBS: Export Payments Where They Apply
The Distributed Energy Buyback Scheme (DEBS) pays eligible Perth households for electricity exported to the Synergy grid. The rate is 10 cents per kWh during peak hours (3pm to 9pm) and 2 cents per kWh at other times.
DEBS is only available to systems with an inverter of 5kW or under. If your inverter is larger than 5kW, you are not eligible for DEBS export payments. This is common with three-phase systems or larger hybrid setups. In this case, maximising self-consumption and battery storage is the only way to capture the value of your generation.
For those who are on DEBS, the 10 cents per kWh peak rate (3pm to 9pm) is worth considering when setting battery discharge schedules. If your battery discharges before 3pm, you are buying that peak-rate capacity back from the grid in the evening instead of exporting solar directly. On a system without a battery, any solar generation that occurs after 3pm and is not used right away exports at the higher rate. This is one reason afternoon west-facing panels can add value to a DEBS-eligible system.
DEBS payments appear as credits on your Synergy bill and are netted against your consumption charges. They do not wipe out the bill entirely for most households. But they reduce it by a meaningful amount for systems with good afternoon generation.
Choosing the Right Synergy Tariff
Your Synergy tariff affects how much you pay for grid electricity and how you benefit from solar. The three main residential options in 2026 are the A1 (standard flat rate), Midday Saver, and the EV plan.
- A1 (standard flat rate): a single rate for all grid electricity, currently around 33.26 cents per kWh. Simple to understand and works well for most solar households. DEBS export credits offset your consumption charges directly.
- Midday Saver: a time-of-use tariff with lower rates during the middle of the day (9am to 3pm) and higher rates in the morning and evening. If you have a battery that is largely charged by your own solar during the day, the Midday Saver rate applies mainly to any top-up grid draw during those hours, which should be minimal. Midday Saver can work against solar owners if a lot of grid draw happens in the evening at the higher rate. Worth checking against your actual usage before switching.
- EV Plan: designed for households with electric vehicles. Includes a very low overnight rate for EV charging (11pm to 6am) and higher daytime rates. If you charge a vehicle overnight, this tariff can work well, but the higher daytime rates mean solar self-consumption matters even more.
The right tariff depends on your usage pattern, system size, and whether you have a battery or EV. A chat with your Positive Energy Solutions consultant can help identify which option suits your household best.
Seasonal Adjustments: Summer vs Winter
Perth’s solar resource changes significantly between summer and winter, and the best savings strategy adapts with the seasons.
Summer:
- Longer days and higher sun angle mean more generation, often 30 to 50% more daily output than winter.
- Battery reaches full charge earlier in the day. Excess generation has nowhere to go if self-consumption is not managed.
- Air conditioning is the biggest load. Running it during peak generation hours (pre-cooling before 3pm) avoids evening grid draw.
- Export to the grid is more likely in summer. DEBS eligible households benefit most in these months.
Winter:
- Shorter days and lower sun angle reduce daily generation. The battery may not reach full charge on overcast days.
- Heating loads shift to morning and evening when generation is low, so timing becomes more important.
- Pool pump hours can be reduced. Less filtration is needed in cooler months, which reduces load.
- Hot water heating may need to run longer. Consider whether the solar window is long enough to cover it or whether a grid top-up is needed.
Checking your battery’s state of charge at the end of each day gives you a quick read on whether your system is well matched to the season. A battery consistently running flat in winter may mean your usage pattern needs adjustment, or that extra capacity would help.
Using Your Monitoring App to Improve Over Time
Your monitoring app is not just a display, it is a tool for spotting problems. The households that get the most from their solar and battery systems are the ones that check the data now and then and adjust their habits.
A few things worth tracking:
- Self-consumption rate: the share of your solar generation you use directly or via battery, rather than exporting. A well-optimised household typically achieves 70% to 90% self-consumption. If yours is lower, there is room to improve through appliance timing or battery settings.
- Self-sufficiency rate: the share of your total electricity needs met by your own solar and battery. This is the number that shows how much of your bill you have cut. Most solar households with a battery achieve 80% to 95% self-sufficiency in summer; winter figures are lower.
- Grid import timing: check when during the day your home draws from the grid. If a lot of import is happening during solar hours, there is an appliance or a habit that can be shifted.
- Battery depth of discharge: if the battery is running flat regularly before morning, either your evening use is higher than your battery can cover, or the minimum reserve is set too high. Adjusting one or both can improve overnight coverage.
Most monitoring apps give weekly and monthly summaries that make these trends easy to spot. Checking them once a month, especially in the first year, builds a clear picture of how your system and your household interact.
A Bonus: Synergy Battery Rewards VPP
If you received the WA Residential Battery Scheme rebate ($1,300), your battery is enrolled in the Synergy Battery Rewards Virtual Power Plant. Synergy can call on your battery to export during high-demand events, up to 30 times per year, and pays 70 cents per kWh for energy exported during those events.
This is fully automatic. You do not need to do anything during an event, and the battery recharges afterwards. The typical yearly payment is between $130 and $350 depending on battery size and number of events. Think of it as a modest bonus that sits on top of your everyday savings, not a main strategy, but a welcome extra for those enrolled.
Get a System Designed to Perform From Day One
The strategies in this guide make the biggest difference when they are built on a well-designed system in the first place: the right panel count, the right inverter size, and the right battery capacity for your household. If you are still choosing a system, or want a second opinion on whether your current setup is well tuned, visit the Positive Energy Solutions showroom in Osborne Park or request a quote online.
Related guides
- Adding a Battery to Your Existing Solar System in Perth: 2026 Costs, Rebates, and Inverter Compatibility Guide
- How Much Can You Save with Solar and Battery in Perth? 2026 Breakdown
- Parker Lane Green Loan Perth 2026: Solar and Battery Finance When the WA Scheme Doesn't Apply
- Solar Battery Finance Perth 2026: WA Scheme, Plenti and Parker Lane Explained
Frequently Asked Questions
What is the best time of day to run appliances with solar in Perth?
The peak solar generation window in Perth is roughly 9am to 3pm, with maximum output around midday. Running high-draw appliances, dishwasher, washing machine, pool pump, hot water system, during this window gets you the most use out of your own solar generation, and avoids grid imports at full retail rates.
Does it matter what direction my panels face for self-consumption?
North-facing panels produce the most energy overall and perform best during the midday generation window, ideal for appliance timing. East-facing panels produce more in the morning, which is great for early battery charging, getting the battery full earlier in the day so it is ready for the evening peak. West-facing panels are even better for battery conservation. By generating through the afternoon and into early evening, they cover your home’s load later in the day and delay the point at which the battery needs to start discharging. This means more battery capacity is kept in reserve for overnight use. For DEBS eligible systems (inverter 5kW or under), west-facing panels also export at the higher 10 cents per kWh peak rate from 3pm to 9pm. A mix of north and west facing panels often delivers the best overall outcome for households with a battery.
How do I know if my battery minimum reserve is set correctly?
Check your battery state of charge at two points: first thing in the morning (it should be close to your minimum reserve setting, not flat) and at the end of the day (it should be close to 100% on a clear sunny day). If the battery is flat before morning, your evening use is going over your battery’s usable capacity. If it rarely goes below 50%, you may have more capacity than your usage needs, or your minimum reserve is set higher than needed.
I have a larger inverter, does any of this still apply?
Yes, most of it applies even more. If your inverter is larger than 5kW and you are not eligible for DEBS export payments, every unit you export to the grid earns nothing. Self-consumption and battery storage are the only ways to capture the value of your generation. Appliance timing and battery settings become even more important for larger systems.
Is it worth switching to the Synergy Midday Saver tariff?
It depends on your usage pattern. Midday Saver lowers rates during 9am to 3pm (when your solar is generating and grid import should be minimal) but raises rates outside those hours. For households with high evening loads that cannot be shifted, the higher evening rate can outweigh the midday benefit. The best way to check is to run your actual usage data against both tariff structures. Your Positive Energy Solutions consultant can help with this.
What self-consumption rate should I be aiming for?
A well-optimised household with a battery typically achieves 75% to 90% self-consumption, meaning 75 to 90 cents in every dollar of solar generation is used by the household rather than exported. Without a battery, 40% to 60% is more typical. If your self-consumption rate is lower than expected, appliance timing changes and a review of your battery settings are the first things to look at.
About the Author
Jason Wiktorowicz
Sales Manager, Positive Energy Solutions | Perth, WA
Jason has been at the centre of Western Australia’s energy transition for over a decade. As Orchestration Lead on Project Symphony — WA’s largest virtual power plant pilot — and Stream Lead on Project Encore, he worked directly with AEMO, Western Power and Energy Policy WA to shape how distributed energy resources connect and operate on the SWIS. That work included developing and rolling out CSIP-AUS, now mandatory for all new WA grid connections. He also led Emergency Solar Management (ESM), the first program of its kind in WA, VPP for Schools (VPP4S), which provided direct market benefits through Supplementary Reserve Capacity, and REBAR, the WA Residential Battery Rebate scheme.
His earlier career spanned Synergy, Infinite Energy and Curtin University’s Sustainability Policy Institute, where he co-authored peer-reviewed research on net-zero urban precincts, solar integration and peer-to-peer energy trading, published in the journal Urban Planning in 2018.
At Positive Energy Solutions, Jason leads sales with a focus on system design accuracy and long-term performance. Positive Energy Solutions installs solar and battery systems, EV chargers and heat pumps, and holds partner accreditations with Fronius, SigEnergy, iStore and SunPower. Connect with him on LinkedIn.
