Most Perth solar guides are written for the average household. A family using 20 to 25 kWh per day who wants to reduce their Synergy bill. That is a reasonable starting point. But if your home has a pool, ducted reverse-cycle air conditioning, and an electric vehicle, the average guide is not really written for you.
A high-energy Perth home can easily use 40 to 55 kWh per day. That is two to three times the typical household load — and it changes everything about how a solar and battery system should be sized, what inverter and battery you need, and how the economics stack up.
The good news is that high-energy homes get some of the best returns on solar and battery investment available. Positive Energy Solutions installs solar and battery together on every job — and homes with pools, ducted AC, and EVs are exactly the customer profile this model is built for. This guide explains how to size a system for your situation and what to expect.
1. What High-Energy Loads Actually Use in Perth
Before sizing anything, you need to understand what each load actually draws. Perth’s climate and driving patterns make some of these numbers different from national averages.
Pool pump
A variable-speed pool pump running 6 to 8 hours per day uses 6 to 10 kWh per day. If your pool has a heat pump for year-round temperature control — common in Perth given the mild winters — add another 10 to 18 kWh per day during the cooler months of May through September. Annual pool energy consumption: 2,500 to 9,000 kWh depending on whether a heat pump is fitted.
Ducted reverse-cycle air conditioning
Perth’s summers are genuinely hot and increasingly long. A 14 kW ducted system running 6 hours per day in summer draws 14 to 20 kWh per day. In shoulder months (spring and autumn) this drops to 4 to 8 kWh per day, and in winter it is similar for heating. Annual AC energy: 4,000 to 7,000 kWh — often the single largest load in the house.
Electric vehicle charging
A typical Perth commuter driving 40 to 60 km per day uses 8 to 12 kWh per day for EV charging. If your household has two EVs, or one driver with a longer commute, this figure doubles. Annual EV energy per vehicle: 3,000 to 4,500 kWh. This is also one of the most flexible loads in the home. The timing of EV charging can be moved entirely to solar generation hours with the right setup.
Base household load
Fridge, lighting, cooking, hot water, entertainment, and other standard consumption adds 10 to 14 kWh per day for a typical Perth family home.
Total consumption profile
Adding these together, a Perth home with pool, ducted AC, one EV, and base household load lands at approximately 40 to 55 kWh per day. One notable feature of this consumption profile: it is roughly consistent year-round. Summer AC load is offset by winter pool heating; EV charging is constant. This actually makes system sizing more straightforward than for a household with extreme seasonal swings.
2. Why Solar Without a Battery Does Not Work for High-Energy Homes
A standard 6.6 kW or even 10 kW solar-only system installed on a high-energy home produces a reasonable amount of energy during the day, but it misses the point. Here is why.
A 10 kW solar system in Perth generates around 45 to 50 kWh on a good summer day — roughly matching total daily consumption. But the timing is wrong. Solar generates from around 7am to 6pm, peaking in the middle of the day. AC runs hardest from 3pm onwards and into the evening. EVs are typically charged overnight. A pool pump can be scheduled to the middle of the day, but the heat pump and evening loads cannot be moved.
Without a battery, a high-energy home with 10 kW of solar still imports significant electricity from the grid in the evenings and overnight — at 30c/kWh or more on Synergy’s standard A1 tariff. The solar export during the middle of the day earns a DEBS credit of 2c/kWh. The maths does not favour a solar-only setup for this consumption profile.
A battery changes the equation entirely. A 13 to 20 kWh battery charged from midday solar can cover most of the evening AC load, the early evening EV top-up, and overnight base consumption. Self-sufficiency moves from roughly 40 percent on solar-only to 80 to 90 percent on solar-plus-battery — and annual savings increase accordingly.
Positive Energy Solutions installs solar and battery together on every project. For high-energy homes, this is not a luxury upgrade — it is what makes the economics work.
3. What Size System Does a High-Energy Perth Home Actually Need?
The sizing question has two parts: how much solar, and how much battery.
Solar array size
To cover 45 to 55 kWh per day in Perth (5.4 to 5.6 peak sun hours daily average), the required DC array size before losses is roughly 10 to 11 kW. But there are good reasons to go larger:
- A larger array generates more midday surplus to charge a battery fully, even on partially cloudy days.
- Perth’s west-facing afternoon generation window is valuable for catching summer peak demand — a larger array captures more of it.
- Panels have degraded to 95-plus percent by the time your EV arrives (or your second EV).
For a high-energy Perth home, Positive Energy Solutions typically recommends 13 to 15 kW of panels. This generates approximately 55 to 65 kWh on a good summer day, providing enough surplus to fully charge a 15 to 20 kWh battery and still cover daytime loads — including the pool pump running on solar during generation hours.
Battery size
The battery needs to cover evening and overnight loads not met by the solar array. For a typical high-energy home, this means:
- Evening ducted AC: 8 to 12 kWh (3pm to 9pm)
- EV top-up overnight: 4 to 8 kWh (if not fully solar-charged during the day)
- Overnight base consumption: 5 to 7 kWh
Total evening and overnight demand: 17 to 27 kWh. A 13.5 kWh battery covers the minimum case; for full coverage including a pool heat pump winter load, 20 to 27 kWh of usable capacity is a better target.
Positive Energy Solutions’ battery range scales to meet this. The SigEnergy SigenStor stacks to 54 kWh usable capacity. The BYD Battery-Box Premium HVS/HVM reaches 66 kWh. The Tesla Powerwall 3 at 13.5 kWh usable can be paired with multiple units where budget allows. The right battery depends on load profile, budget, and how much backup capability matters to you.
Note: Under WA regulations, residential battery installations are currently limited to a maximum of three battery stacks in most configurations. Positive Energy Solutions will confirm what is achievable for your specific setup during the design process.
4. Scheduling Loads for Maximum Solar Self-Consumption
Sizing the system correctly is step one. Getting the scheduling right is where the real savings come from. The goal is to shift as many high-energy loads as possible into the solar generation window — roughly 9am to 4pm for peak generation, with useful output from 7am to 6pm.
- Pool pump: Schedule to run from 10am to 4pm. Most modern variable-speed pumps have timer settings; if yours does not, a basic smart switch handles this. Running the pool pump in the solar generation window removes 6 to 10 kWh from the evening and overnight import load.
- Pool heat pump (winter): Schedule to run from 10am to 2pm when solar output is strongest. This is the highest-draw load in many high-energy homes; running it on solar rather than grid is a significant saving.
- EV charging: Set the charger to solar mode if supported (available on most modern EV chargers including Wallbox, Zappi, and integrated solutions from SigEnergy). This ensures the EV only draws power when there is a solar surplus, minimising battery depletion and grid import.
- Ducted AC pre-cooling: Set the AC to run at maximum cooling from 1pm to 3pm, using solar to cool the house’s thermal mass before the evening peak. Many Perth homes can coast through to 8pm or later on pre-cooling alone in summer.
- Hot water: If you have a heat pump hot water system, schedule it to run at 10am. Heat pump hot water on solar is at almost no cost water heating.
Positive Energy Solutions installs SigEnergy SigenStor batteries with built-in AI energy management on most residential projects. The SigenStor system learns household consumption patterns and adjusts battery charging and discharging automatically — including prioritising load scheduling to maximise solar self-consumption without manual timer programming. For EV integration and pool load management, the AI scheduling handles the optimisation that would otherwise require manual setup.
5. Inverter and Battery Selection for High-Energy Homes
Not all inverters and batteries are equally suited to high-energy home profiles. Several factors matter specifically for this use case.
Inverter: continuous output capacity
A high-energy home may have the pool pump, ducted AC, and EV charger running simultaneously. The peak draw from these loads combined can exceed 10 kW. An inverter rated at 5 kW continuous output will clamp generation and limit what the battery can deliver in parallel. Positive Energy Solutions specifies the Fronius GEN24 PLUS (available in 6, 8, and 10 kW ratings) and SigEnergy hybrid inverters (8 and 10 kW) for this reason — both are sized for simultaneous high-load scenarios.
Battery: round-trip efficiency and continuous discharge rate
A battery that holds 20 kWh but can only discharge at 5 kW continuous is a bottleneck for a home trying to run ducted AC plus lights plus other loads from storage. The SigenStor and Tesla Powerwall 3 both offer high continuous discharge rates (5 kW per unit for SigenStor, 11.04 kW continuous for the Powerwall 3) that are appropriate for high-energy home profiles.
Three-phase consideration
Homes with three-phase power can install larger solar systems (up to 30 kW without export limiting concerns), faster EV charging (11 kW single-phase EV charging versus 22 kW on three-phase), and have more flexibility with battery connection. If your home already has three-phase power — common in larger Perth homes built in the last 20 years — Positive Energy Solutions will design your system to take advantage of it. If you are on single-phase, a 13 to 15 kW solar system with export limiting is still viable and sufficient for most high-energy home profiles.
Positive Energy Solutions has a dedicated blog post on three-phase solar and battery systems in Perth if your home is three-phase connected.
6. Cost and Payback for a High-Energy Perth Home
The cost of a well-specified solar and battery system for a high-energy Perth home in 2026, after Federal STC rebates and the WA Cheaper Home Batteries Program:
- 13 to 15 kW solar array (SunPower P-Series): $9,500 to $13,000 installed after STC rebate
- Battery (SigenStor 18 to 27 kWh usable, or equivalent): $6,000 to $14,000 after CHBP and Federal rebates
- Hybrid inverter (Fronius GEN24 PLUS 10 kW or SigEnergy 10 kW): included in above
- EV charger (7 kW wall charger, solar-integrated): $3,200 to $4,000 installed
- Total turnkey (indicative): $18,000 to $28,000 depending on battery capacity and configuration
Annual electricity savings for a high-energy home running 40 to 55 kWh/day, with smart load scheduling and 80 to 90 percent self-sufficiency: $5,000 to $6,500 per year versus a pre-solar Synergy bill. Simple payback at the mid-range: 4 to 5 years.
The key insight: the higher the pre-solar electricity bill, the faster the payback. A household spending $8,000 to $10,000 per year on electricity before solar has a faster payback than one spending $3,000 — and high-energy homes are typically in the former category.
7. Why Positive Energy Solutions Is Built for High-Energy Homes
Positive Energy Solutions does not install solar without a battery. Every system we install is a complete solar and battery setup — designed from the start as a whole-home energy management solution, not a roof-mounted generation source that happens to have storage bolted on.
For the average 20 kWh household, the difference between solar-only and solar-plus-battery is meaningful. For a 50 kWh household with a pool, ducted AC, and an EV, it is the difference between a system that works and one that does not.
Positive Energy Solutions specifies the Fronius GEN24 PLUS hybrid inverter and SigEnergy SigenStor AI battery on most residential projects specifically because these components handle the variable, high-draw loads that high-energy homes generate. The SigenStor’s AI energy management removes the need for manual scheduling across pool, AC, and EV loads. The Fronius GEN24 PLUS provides the continuous output rating to run these loads from solar and battery simultaneously without throttling.
Every Positive Energy Solutions installation also includes Omnidian performance assurance — continuous monitoring of your system’s output by a dedicated after-sales company. For a high-energy home where the ROI depends on consistent performance across a 25-year panel life, active monitoring is not an optional extra.
Talk to Positive Energy Solutions About Your High-Energy Home
If your home has a pool, ducted air conditioning, or an EV — or you are planning to add any of these — a standard sizing guide will not give you an accurate picture. Positive Energy Solutions designs systems around your actual consumption profile, not an average household assumption.
Get in touch with Positive Energy Solutions to discuss your home and get a system design matched to your loads. We will model your solar generation, battery sizing, load scheduling, and expected savings before any commitment.
Related guides
- Best Solar Batteries for Perth Homes in 2026
- How SigEnergy SigenStor Uses AI to Manage Your Home's Energy
- Best Solar Panels Perth 2026: What to Look For and What We Install
- Adding a Battery to Your Existing Solar System in Perth: 2026 Costs, Rebates, and Inverter Compatibility Guide
Frequently Asked Questions
What size solar system do I need for a Perth home with pool, AC and EV?
For a home using 40 to 55 kWh per day — the typical range for pool plus ducted AC plus one EV — Positive Energy Solutions recommends 13 to 15 kW of solar panels paired with 15 to 27 kWh of usable battery storage. Smaller solar systems are undersized for this load profile and result in continued high grid imports during evenings and winter. The battery is essential — solar-only does not deliver adequate self-sufficiency at this consumption level.
Is a battery worth it for a high-energy Perth home?
Yes — and more so than for the average household. High-energy homes have large evening loads (AC, EV) that cannot be met by daytime solar without storage. A battery shifts solar-generated energy to cover these loads, converting what would otherwise be low-value grid export at 2c/kWh into avoided grid import at 30c/kWh or more. For a home spending $8,000 to $10,000 per year on electricity, the battery payback is typically under 5 years as part of a solar-plus-battery system.
Can I charge my EV from solar with a Positive Energy Solutions system?
Yes. Positive Energy Solutions installs solar-integrated EV charging as part of the system design where required. The SigenStor AI energy management can direct surplus solar to an EV charger during generation hours, meaning EV charging costs effectively become zero on most days. For homes with overnight charging habits, the battery covers the EV top-up while the solar array recharges the battery the following day.
Do I need three-phase power for a pool, AC and EV solar setup?
Not strictly. Single-phase Perth homes can run a 13 to 15 kW solar array with export limiting, a 10 kW hybrid inverter, and a battery — sufficient for most high-energy home profiles. However, three-phase power enables faster EV charging (up to 22 kW versus 7 kW on single-phase), larger solar export allowances, and more flexible battery configurations. If your home is already three-phase, Positive Energy Solutions will design the system to use it. We have a dedicated post on three-phase solar and battery systems in Perth.
How much can I save with solar and battery on a high-energy Perth home?
A high-energy Perth home using 40 to 55 kWh per day with a well-specified 13 to 15 kW solar system and 15 to 20 kWh battery typically saves $5,000 to $6,500 per year on electricity costs, assuming smart load scheduling for pool, EV, and AC. The exact saving depends on your tariff, how much of your load is schedulable to solar hours, and seasonal variation. Positive Energy Solutions models this as part of the system design process before any commitment.
What battery does Positive Energy Solutions recommend for a high-energy home?
It depends on how much storage you need and your backup priorities. For most high-energy homes, Positive Energy Solutions recommends the SigEnergy SigenStor — it scales from 9 kWh to 54 kWh usable capacity, has built-in AI load management, and handles the continuous discharge rates needed to run AC and EV loads simultaneously from storage. For homes with extreme overnight loads or strong backup priority, the BYD Battery-Box HVM reaches 66 kWh capacity. We will recommend the right configuration after reviewing your consumption data.
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.
