A modern home energy system can do more than generate solar power. Rooftop panels can supply the house, a battery can store surplus electricity for later, and a smart EV charger can use available solar to charge the car. The challenge is making those parts work together.

Designing a home energy system in 2026 starts with the household—not the biggest products available. Electricity use, EV driving, roof conditions, evening demand, electrical supply and future energy needs should all be considered before choosing system sizes.

When properly planned, solar, battery storage and EV charging can operate as one connected setup rather than three separate purchases.

Key Takeaways

• Start with current electricity use and future EV demand before selecting equipment.
• Solar size should reflect roof conditions, household demand, EV charging and network limits.
• Size the home battery around evening use, surplus solar and backup needs—not the capacity of the EV battery.
• A 7–7.4kW EV charger is enough for many homes; 11kW and 22kW charging generally require suitable three-phase power and vehicle support.
• Solar-aware charging and dynamic load management can help use more rooftop solar at home.
• Check inverter, battery, charger and monitoring compatibility before installation.
• Backup capability should be designed rather than assumed.

How Solar, Battery and EV Charging Work Together

Each component has a different role.

Component	Main role
Solar panels	Generate electricity during daylight hours
Inverter	Converts solar electricity for household use
Home battery	Stores surplus energy for later
EV charger	Charges the vehicle at a controlled rate
Smart meter / CT monitoring	Tracks household imports, exports and energy flow
Energy management system	Coordinates solar, battery, EV and grid use

A typical daytime energy flow might look like:

Solar → Home → EV or Battery → Grid

The EV and battery do not always need to charge in the same order. A household that wants more blackout reserve may prioritise the battery, while someone with a regular daytime charging opportunity may direct more surplus solar into the car. That flexibility is one of the main benefits of designing the system as a whole.

Design the Energy Flow

Once the main components are sized, the next question is how they should operate throughout the day.

Time	Typical energy strategy
Morning	Solar begins covering household loads as generation rises
Midday	Solar powers the home and charges the EV and/or battery
Afternoon	Battery and EV charging adjust to the remaining solar surplus
Evening	Stored battery energy helps reduce grid purchases
Overnight	EV may charge on an off-peak tariff if additional energy is required

The exact strategy will vary between households. A commuter whose EV is away during the day may have limited opportunity for direct solar charging. A work-from-home household may be able to direct much more surplus solar into the vehicle.

This is where smart monitoring and automation become useful. The aim is not simply to own solar, a battery and an EV charger, but to make them respond to the way electricity is actually used.

Solar Panel Systems: Sizing, Cost & Performance

Solar sizing should start with how much electricity the household currently uses and how that demand may change.

Check recent bills or smart-meter data for:

• Average daily electricity consumption
• Daytime versus evening use
• Air-conditioning
• Electric hot water and cooking
• Pool equipment
• Current or planned EV charging
• Future electrification

Future demand matters because a solar system can remain in service for many years. Adding an EV, heat-pump hot-water system or other electric appliances can significantly increase household electricity use.

The Australian Government solar sizing guidance recommends considering electricity consumption, when energy is used, available sunny roof area, local sunshine, tariffs, budget and network limits when selecting system size.

How Much Solar Does a Home with an EV Need?

There is no single solar size that suits every EV household.

Start with:

Household electricity demand + expected EV charging demand

Then consider:

• Whether the EV is home during solar hours
• Roof orientation and shading
• Seasonal solar production
• Battery charging
• Export limits
• Available roof space
• Future household demand

For some EV households, an 8kW, 10kW or larger solar array may make sense where roof conditions and network rules allow it. A household with lower electricity use may not need the same capacity.

Inverter Sizing Matters Too

Solar panel capacity and inverter capacity are not always identical.

For example, Australian Government guidance notes that a 6.6kW solar array is often paired with a 5kW inverter. Panels rarely operate at their full rated output for long periods, although the final design must remain within manufacturer specifications and scheme requirements.

When solar, battery storage and EV charging are combined, inverter output, battery power, phase connection and network limits should be considered together.

Solar System Cost in 2026

Current Aussie Solar Tech pricing provides the following planning guide:

Solar system size	Current guide price	Typical planning context
6.6kW	A$3,999	Small to medium household demand
8kW	A$4,599	Higher daytime use or growing demand
10kW	A$5,599	Higher-use homes or regular EV charging
13kW	A$6,999	High household use, battery storage or EV demand
15kW	A$8,790	Larger high-use homes where site conditions allow

Prices are current guide prices after applicable rebates and may vary according to equipment and installation requirements.

See the Aussie Solar Tech solar system prices guide for current package options.

The largest system that fits on the roof is not automatically the best design. Local network connection and export limits also need to be considered.

Battery Storage: Sizing, Cost & Backup in 2026

A home battery should not be sized according to the capacity of the EV battery.

The stationary battery normally has a different job: storing surplus solar for later household use, reducing grid purchases and providing backup where the system is configured for it.

Battery sizing should consider:

• Evening and overnight electricity use
• Available surplus solar
• Backup requirements
• Electricity tariffs
• Battery power output
• Future household demand
• Budget

Battery capacity is measured in kWh, while battery power output is measured in kW. Both matter. A battery can have enough stored energy for the evening but still be unable to run several large appliances simultaneously if its power output is too low. Australian Government guidance specifically distinguishes battery capacity from rated power output for this reason.

Battery Cost in Australia

Current Aussie Solar Tech estimates provide a useful capacity-based comparison:

Battery capacity	Example inverter capacity	Approx. installed guide price
5kWh	5kW	A$3,499
10kWh	5kW	A$5,099
15kWh	8kW	A$5,799
20kWh	8kW	A$6,799
25kWh	10kW	A$7,299

These are estimated installed prices including an inverter. Brand, configuration, location, backup hardware and installation complexity can change the final cost. For additional capacities and brand comparisons, see the Aussie Solar Tech solar battery price guide.

Should the Home Battery Charge the EV?

It can, but routinely discharging a relatively small home battery into a much larger EV battery may leave little stored electricity for the house.

When the EV is parked at home during daylight hours, direct surplus solar charging can often make more sense.

If the vehicle arrives home after sunset, another strategy is to preserve battery energy for household loads and charge the EV during a cheaper overnight tariff where available.

The best approach depends on electricity tariffs, driving patterns, solar generation and backup priorities.

Battery Rebate in 2026

Eligible battery systems connected to new or existing rooftop solar can receive support through the Australian Government’s Cheaper Home Batteries Program.

From 1 May 2026, the STC factor became tiered according to usable battery capacity:

Portion of usable battery capacity	STC factor applied
0–14kWh	100%
Above 14kWh to 28kWh	60%
Above 28kWh to 50kWh	15%

The STC factor also declines every six months. The changes are intended to maintain an upfront discount of around 30% across eligible battery sizes as battery costs change, although the actual dollar value depends on capacity, STC settings and installation date.

See the Clean Energy Regulator battery rebate guidance for the current rules. A larger battery should therefore be selected because the household can use the additional storage—not simply because a larger system is available.

Backup Power Needs to Be Designed Separately

Having a battery does not automatically mean every appliance will continue operating during a blackout.

Backup design	What it generally means
Essential-load backup	Priority loads such as refrigeration, lighting and internet
Selected-circuit backup	A chosen group of household circuits
Whole-home backup	Most or all household loads where system power allows

Actual backup capability depends on:

• Battery state of charge
• Battery discharge power
• Inverter output
• Backup hardware
• Circuit configuration
• Appliances operating at the same time

Australian Government guidance confirms that a battery must be configured for blackout backup and that some systems support the whole property while others only support selected circuits. High-power appliances such as an EV charger, large oven or powerful air-conditioner may be excluded unless the system has specifically been designed to support them. Backup requirements are best decided before installation because adding backup circuits later can require additional electrical work.

EV Charger Design: 7kW, 11kW or 22kW?

The fastest charger is not automatically the right charger. A standard household power point can charge an EV at up to around 2.4kW, while dedicated home chargers generally operate between 7kW and 22kW.

Home EV Charging Options

Charging option	Typical maximum power	Electrical setup	Often suited to
Standard power point	Up to 2.4kW	Standard 240V outlet	Low daily kilometres or occasional charging
7–7.4kW charger	7–7.4kW	Usually single-phase dedicated circuit	Most everyday home charging
11kW charger	11kW	Usually three-phase dedicated circuit	Higher daily charging demand
22kW charger	Up to 22kW	Three-phase dedicated circuit	High demand where the EV supports 22kW AC

Actual charging speed is limited by:

1. Charger output
2. Available electrical supply
3. The EV’s onboard AC charger
4. Vehicle and battery conditions

Installing a 22kW charger does not mean every EV will accept 22kW. Government guidance notes that Type 2 AC charging can provide up to 22kW, while some vehicles accept only 11kW AC.  For many households, a 7–7.4kW charger already provides plenty of capacity for overnight top-ups.

Single-Phase vs Three-Phase

Single-phase power is suitable for many residential solar, battery and EV systems.

Three-phase becomes more useful where the property has several large electrical loads or genuinely requires higher-rate 11kW or 22kW AC charging.

Before deciding on a charger, an electrician should assess:

• Existing electrical supply
• Main switch capacity
• Solar and battery inverter output
• Other large household loads
• EV onboard charger limit
• Network requirements

For a new build or major renovation, planning the charger cable route, conduit and switchboard capacity before walls, landscaping or driveways are completed can also reduce additional work later.

EV Charger Cost

Several home EV charger options are available at different power levels and price points:

EV charger	Power options	Guide hardware price
Myenergi Zappi	7.4kW / 22kW	From A$1,245
SolarEdge EV Charger	7.4kW	Around A$1,300–A$1,800
Sigenergy Sigen EV AC Charger	7kW / 11kW / 22kW	From around A$1,239
GoodWe EV Charger	7kW / 11kW / 22kW	From around A$840

Installation costs vary with cable length, switchboard condition, phase configuration and any additional electrical work.

Solar Surplus Charging and Dynamic Load Management

A solar-aware EV charger can monitor energy flowing through the property. When rooftop generation exceeds household demand, more power can be directed into the vehicle. If solar generation falls or another large appliance switches on, charging can reduce. This can increase solar self-consumption instead of exporting surplus electricity during the day and buying more electricity later for EV charging.

It is better described as low-cost surplus solar charging rather than automatically calling it free, because exported solar may otherwise have earned a feed-in tariff.

Dynamic Load Management

Dynamic load management helps keep total household demand within the available electrical capacity. For example, if the EV is charging while an oven and air-conditioner are operating, a compatible charger can temporarily reduce charging power. When household demand falls, charging can increase again.

This can be more practical than selecting the highest-powered charger and upgrading the entire electrical supply simply to accommodate its maximum output.

System Integration: AC/DC Coupling and Compatibility

Solar and battery storage can generally be integrated in two ways.

Design	Often suits	Main consideration
DC-coupled / hybrid	New solar + battery installations	Solar and battery generally share a hybrid inverter
AC-coupled	Adding a battery to existing solar	Existing solar inverter can often remain

Australian Government guidance says either arrangement can be used when installing solar and a battery together, while AC coupling is the usual arrangement when adding a battery to an existing solar system.

Neither approach is automatically better.

The decision should consider:

• Existing solar equipment
• Battery compatibility
• Inverter limits
• Backup requirements
• Future expansion

Using equipment from one ecosystem can simplify monitoring and energy control. Mixing brands can provide greater flexibility, but compatibility should be checked before purchase.

A charger described as solar compatible does not necessarily communicate directly with every battery or inverter. Some chargers instead use CT monitoring at the switchboard to measure imports and exports and adjust charging accordingly.

V2H and V2G: Worth Future-Proofing For?

Vehicle-to-home (V2H) allows a compatible EV to provide stored energy back to a home.

Vehicle-to-grid (V2G) can allow a compatible EV and bidirectional charger to send electricity back to the electricity network.

Australia is continuing to develop V2G and smart-charging capability, but it should still be treated as a future-proofing consideration rather than a standard feature available to every household in 2026.

Compatibility can depend on:

• EV model
• Bidirectional charger
• Approved equipment
• Electrical system
• Retailer and network requirements

Do not pay extra for assumed bidirectional capability unless the intended EV and charger combination is confirmed to support it.

Example Home Energy System Designs

These are planning examples rather than fixed packages.

Household profile	Solar	Battery	EV charger	Main goal
Moderate-use home + short EV commute	6.6–8kW	5–10kWh optional	7–7.4kW	Increase daytime solar use
Family home + regular EV charging	8–10kW	Around 10–15kWh	7–11kW	Balance EV and evening demand
High-use all-electric home + EV	10–13kW+ where suitable	15–20kWh+ if justified	11kW where suitable	Manage several large electrical loads
Very high-use home or multiple EVs	13–15kW+ where suitable	20–25kWh+ if justified	Up to 22kW where suitable	Manage higher demand and future electrification

These ranges should not replace a site-specific design.

A property with limited roof space may rely more heavily on off-peak EV charging. Another home with a large sunny roof and an EV parked there during the day may benefit from more rooftop solar and need less stationary storage.

The household’s actual energy profile should determine the final design.

Common Home Energy System Design Mistakes

Mistake	Better approach
Choosing products before analysing electricity use	Check current and future demand first
Installing the largest solar system without checking network limits	Confirm inverter and export limits first
Sizing the home battery from the EV battery	Base storage on household use and surplus solar
Looking only at battery kWh	Check both capacity and power output
Installing the fastest EV charger available	Match charger power to the EV and electrical supply
Assuming a battery means whole-home backup	Define backup circuits before installation
Mixing equipment without checking compatibility	Confirm monitoring and control requirements first
Ignoring dynamic load management	Consider smart control where several large loads operate
Designing only around today’s demand	Allow for future EVs and electrification

Final Verdict: How Should You Design a Home Energy System in 2026?

The best home energy system is not necessarily the biggest one. Start with household electricity consumption and future EV demand. Choose enough solar to cover a useful share of that consumption, while considering roof conditions and network limits. Then size battery storage around surplus solar, evening use and backup requirements. For EV charging, match the charger to the vehicle, electrical supply and actual driving pattern instead of assuming that faster is always better. Finally, make sure the components can work together.

A properly designed solar, battery and EV charging system can increase solar self-consumption, reduce unnecessary grid purchases and provide room for future electrification without paying for capacity the household may never use.

The financial return also depends on how the system is operated. A household that can charge an EV from daytime solar and use stored solar after sunset may reduce more grid purchases than a similar property that exports most of its generation.

Frequently Asked Questions

What Size Solar System Do I Need With an EV?

There is no universal size. It depends on household electricity consumption, driving requirements, roof conditions, available daytime charging, battery plans and network limits. Future EV demand should be included rather than sizing solar only from the current electricity bill.

Is a 7kW EV Charger Enough for Home Charging?

For many households, yes. A 7–7.4kW charger is suitable for regular overnight charging. An 11kW or 22kW charger becomes more useful where the vehicle supports the higher AC rate and the property has a suitable three-phase supply.

How Big Should a Home Battery Be With an EV?

Do not size the home battery from the EV battery capacity. Focus on evening household use, available solar surplus, electricity tariffs, backup requirements and battery output power.

Can I Charge My EV Using Solar?

Yes. A compatible solar-aware charger can adjust charging according to available rooftop solar and household demand. The amount of surplus solar available will vary throughout the day and across seasons.

Can I Add a Battery and EV Charger to Existing Solar?

Usually, yes. The existing inverter, switchboard, electrical supply, network connection and equipment compatibility should be assessed first. AC coupling is commonly used when a battery is added to an existing solar installation.