Solar Battery Tariffs Cardiff NSW: Worked Example | Kratos

Battery Tariffs in Cardiff: A Worked Time-of-Use Example

If you are considering a home battery in Cardiff NSW 2285, battery size is only one part of the financial equation.

Your electricity tariff can materially change how valuable the battery becomes.

A battery can potentially:

• Store excess daytime solar

• Reduce expensive evening grid imports

• Charge when electricity is cheaper

• Discharge when electricity is more expensive

• Reduce reliance on low feed-in tariffs

• Maintain a reserve for blackout backup

But the numbers depend heavily on when you use electricity and what your retailer charges at those times.

For this reason, the better question is not simply:

“How much can a 10kWh battery save?”

It is:

“What electricity is the battery replacing, and what would that electricity otherwise cost?”

Kratos Energy offers residential battery systems designed around solar production, household consumption and storage requirements. Explore Kratos battery storage options. Kratos Energy

What Is a Time-of-Use Electricity Tariff?

A time-of-use, or TOU, plan charges different electricity prices depending on when energy is consumed.

Typical categories include:

Peak

The most expensive electricity period.

Off-peak

Lower-priced periods when demand on the network is lower.

Shoulder

An intermediate price used by some plans.

Ausgrid explains that its current network time-of-use peak window is generally 3 PM–9 PM during June–August and November–March, with off-peak applying outside that window and no network peak period during April, May, September or October. However, retailers can set different retail rates and time windows, so the times on your actual electricity plan remain the ones that matter for your bill. Ausgrid

That distinction is critical when configuring a battery.

Why Cardiff Battery Owners Should Look at the Tariff First

Cardiff is within the Ausgrid distribution network, with Ausgrid's own outage records identifying Cardiff within its service area. Ausgrid

But Ausgrid is not your electricity retailer.

Ausgrid manages the network.

Your retailer determines the electricity plan shown on your bill.

Two neighbouring Cardiff homes could therefore have:

• The same network

• Similar solar systems

• Similar batteries

but very different battery economics because they use different retail plans.

Before modelling a battery, check your latest bill for:

Peak rate + off-peak rate + feed-in tariff + daily supply charge.

Battery Tariffs: The Basic Financial Logic

Imagine solar electricity is being exported during the day for:

8c/kWh

but the home later buys electricity during an evening peak period at:

56c/kWh.

The household is effectively:

Selling electricity cheaply during the day

and then:

Buying electricity back at a much higher price later.

A battery can interrupt that cycle.

Instead:

Solar → battery → evening home consumption

The financial benefit comes from the difference between:

the value you give up by not exporting

and

the grid electricity purchase you avoid later.

Worked Example: Cardiff Solar + Battery

The following example is deliberately transparent and illustrative only.

For the tariff inputs, we use rounded figures based on a current residential TOU offer shown on the Australian Government's Energy Made Easy service in an Ausgrid area as viewed in September 2026.

That example plan lists:

• Peak electricity: 56.58c/kWh

• Off-peak electricity: 22.59c/kWh

• Peak period: 3 PM–8:59 PM during specified summer and winter seasons

• Solar feed-in option: up to 8c/kWh

Retail plans change and eligibility differs by postcode, meter and customer. These figures are not a claim that this exact offer is available at every Cardiff address. Always compare the current offers available for postcode 2285 and your meter configuration. Energy Made Easy

Worked Example Assumptions

Consider a hypothetical Cardiff household with:

The 90% efficiency figure is an illustrative modelling assumption, not a specification for every battery.

Actual usable efficiency varies by equipment and operating conditions.

Scenario 1: No Battery

Without a battery, assume the household exports the full:

10kWh

during the day.

At an 8c/kWh feed-in tariff:

10 × $0.08 = $0.80 export credit

Later, the household uses:

9kWh during the peak period

At 56.58c/kWh:

9 × $0.5658 = $5.09 grid cost

So for these two energy flows:

Peak import cost:

$5.09

Solar export credit:

−$0.80

Net:

$4.29

Again, this is only the variable-energy component being modelled. It excludes the daily supply charge and other household consumption.

Scenario 2: Charge the Battery From Excess Solar

Now suppose the 10kWh of daytime surplus is used to charge the battery instead.

Using the assumed 90% round-trip efficiency:

10kWh in → approximately 9kWh returned

The household can then use around:

9kWh during the peak period

instead of buying it from the grid.

Avoided peak purchase:

9 × $0.5658 = $5.09

But because the solar was stored rather than exported, the household gives up:

10 × $0.08 = $0.80

in feed-in credits.

So the approximate additional energy value created by shifting that solar becomes:

$5.09 − $0.80

= $4.29 for that example day

This does not mean a battery will save $4.29 every day.

Solar surplus, evening consumption, seasonal tariffs and battery state of charge all change throughout the year.

Why the Feed-In Tariff Changes the Result

Suppose the same household receives only:

3c/kWh

for exported solar.

The 10kWh export would then be worth:

10 × $0.03 = $0.30

The battery still delivers approximately:

9kWh

during the example peak period, avoiding approximately:

$5.09

in peak imports.

Difference:

$5.09 − $0.30

= $4.79

This illustrates an important principle:

As feed-in tariffs fall relative to retail electricity prices, storing excess solar can become more financially valuable than exporting it.

Kratos' current Feed-in Tariff Calculator similarly notes that 2026 export rates are generally much lower than retail import rates and that actual retailer tariffs should be entered for an accurate result. Kratos Energy

Check your solar export value with the Kratos Feed-in Tariff Calculator.

Scenario 3: Charging the Battery From Off-Peak Grid Power

Some battery systems can also be programmed to charge from the grid.

This can create another strategy:

Buy cheap electricity off-peak → store it → use it during peak

Using the same illustrative tariff:

Battery charging

10kWh purchased at:

22.59c/kWh

Cost:

10 × $0.2259 = $2.26

With 90% round-trip efficiency, the battery returns approximately:

9kWh

If that 9kWh replaces peak electricity worth:

56.58c/kWh

avoided peak purchase is:

9 × $0.5658 = $5.09

The theoretical tariff spread becomes:

$5.09 − $2.26

= $2.83 for that cycle

But this is not $2.83 of guaranteed profit.

The calculation has not included:

• Battery degradation

• Battery purchase cost

• Standby consumption

• Other conversion losses

• Retail plan fees

• Seasonal changes

• Battery reserve settings

• VPP operation

• Restrictions on grid charging

The example simply shows why tariff spread matters.

Solar Charging vs Grid Charging

For many solar households, charging the battery from excess rooftop solar will make more intuitive financial sense than charging from normal grid electricity.

Why?

Because the opportunity cost of excess solar may only be the feed-in tariff.

Using the example above:

Solar charging cost

Foregone export value:

8c/kWh

Off-peak grid charging cost

Electricity purchase:

22.59c/kWh

So excess solar is a much cheaper source of battery energy in this example.

Grid charging becomes more interesting when:

• Off-peak rates are unusually low

• Free-energy windows are available

• Solar production is weak

• A high evening peak rate applies

• The battery needs to preserve backup reserve

• The retailer specifically supports battery arbitrage

What About Free Midday Electricity Plans?

From 1 July 2026, the Australian Government introduced the regulated Solar Sharer Offer in eligible areas.

The offer includes a three-hour period around the middle of the day where the first 24kWh of electricity use can be free, with additional usage charged at the relevant off-peak or solar-soak rate. Energy Made Easy

That can materially change battery strategy.

For an eligible customer whose battery supports scheduled grid charging, a possible pattern might be:

Free midday grid energy → battery → evening consumption

However, do not assume every Cardiff household automatically has this plan.

Plan availability, eligibility, meter configuration and retailer conditions need to be checked through Energy Made Easy or directly with the retailer.

Battery Value Depends on When You Use Electricity

Consider two Cardiff homes with identical solar and battery systems.

Home A

Evening consumption:

12kWh

Daytime solar surplus:

10kWh

This household has substantial energy available to store and substantial demand to use it later.

Home B

Evening consumption:

3kWh

Daytime solar surplus:

10kWh

A large battery may fill during the day but have little household demand to serve overnight.

Same equipment.

Very different utilisation.

This is why battery sizing should start with smart-meter data, not package size.

Check These Four Numbers on Your Electricity Bill

Before modelling battery savings, identify:

1. Peak rate

What do you pay during the expensive period?

2. Off-peak rate

What does electricity cost during the cheapest period?

3. Feed-in tariff

What are you currently paid for exporting solar?

4. Daily supply charge

This usually remains even after installing a battery.

The battery primarily changes your usage charges, not the fixed daily network connection cost.

Smart-Meter Data Makes the Calculation Much Better

A quarterly bill can tell you how much electricity you consumed.

But smart-meter interval data tells you when you consumed it.

That is particularly important for a battery.

Energy Made Easy notes that smart-meter data records electricity usage in 30-minute intervals and allows much more accurate comparison of time-of-use plans than generic household benchmarks. Energy Made Easy

For a Cardiff battery assessment, the most useful data is:

• Midday solar exports

• 3 PM–9 PM grid imports

• Overnight imports

• Seasonal changes

• Weekend vs weekday consumption

This shows how many kWh the battery could actually shift.

Should You Choose a Time-of-Use Tariff Just Because You Have a Battery?

Not automatically.

A battery can make TOU pricing more attractive because it may reduce consumption during expensive periods.

But the whole electricity plan still needs to be compared.

Look at:

• Peak rate

• Off-peak rate

• Supply charge

• Feed-in tariff

• Controlled-load tariff

• Discounts

• Fees

• VPP conditions

A plan offering a very low off-peak rate may also have:

• A higher peak rate

• Higher supply charge

• Lower solar feed-in tariff

So do not choose a tariff from one attractive number.

Energy Made Easy is designed to compare plans available at your postcode and can use actual smart-meter data where available. Energy Made Easy

What About a Single-Rate Tariff?

A flat or single-rate plan charges broadly the same usage rate regardless of the time of day.

Battery economics are different under this arrangement.

If you pay:

32c/kWh all day

rather than having a 56c peak period, avoiding evening grid imports is still valuable.

But there is less opportunity for tariff arbitrage between cheap and expensive time windows.

Under a single-rate tariff, the financial case is often driven more heavily by:

low feed-in tariff → battery storage → avoided retail electricity purchase

rather than peak/off-peak price differences.

Battery Settings Should Match the Tariff

Modern battery systems can offer operating modes such as:

• Self-consumption

• Time-of-use

• Backup reserve

• Scheduled charging

• Scheduled discharge

• VPP control

The correct setting depends on what you want the battery to achieve.

Self-Consumption Mode

Prioritises storing excess solar for later household use.

Time-of-Use Mode

May charge or preserve energy during cheaper periods and discharge during expensive periods.

Backup Reserve

Keeps part of the battery available for power outages.

The more capacity reserved for backup, the less is available for everyday tariff optimisation.

Kratos' battery range is designed around both solar storage and backup capability, depending on the selected equipment and system configuration. Kratos Energy

What If You Join a Virtual Power Plant?

A Virtual Power Plant (VPP) may allow a provider to control some battery charging or discharging in exchange for financial incentives or energy-plan benefits.

This can affect your tariff strategy.

Before joining, check:

• Who can control the battery?

• How much reserve remains for your household?

• Can the battery discharge to the grid?

• What payments or credits apply?

• Is there an exit fee?

• Does the agreement change your retail tariff?

• How does it affect blackout reserve?

Do not model a VPP benefit and normal battery savings independently if both rely on the same stored electricity.

Does the 2026 Battery Rebate Improve the Economics?

Eligible batteries connected to rooftop solar can currently receive support through Australia's Cheaper Home Batteries Program.

From 1 May 2026, battery STC support became tapered:

• First 14kWh — full applicable factor

• Above 14kWh to 28kWh — 60%

• Above 28kWh to 50kWh — 15%

The Clean Energy Regulator says the updated structure is intended to maintain support broadly around a 30% installation discount across battery sizes, although actual dollar values depend on certificate rates and eligibility. Clean Energy Regulator

You can estimate the current support using the Kratos Battery Rebate Calculator. Kratos Energy

The rebate reduces upfront cost.

It does not make an oversized or poorly utilised battery financially efficient.

Cardiff Battery Tariff Checklist

Before buying a battery, collect:

Without these numbers, an advertised battery-savings figure is largely guesswork.

Frequently Asked Questions

Battery Tariffs in Cardiff: The Bottom Line

For a Cardiff NSW 2285 household, the financial value of a battery depends on much more than battery capacity.

Start with:

Solar exports → evening imports → peak tariff → off-peak tariff → feed-in tariff → battery efficiency.

The worked example demonstrates the basic logic:

Without storage

Solar may be exported for a relatively small credit while expensive electricity is purchased later.

Solar-charged battery

Excess daytime energy can be shifted into the evening.

Off-peak grid charging

A sufficiently large price difference can create additional tariff-management opportunities.

But none of these strategies produces a guaranteed saving.

Your result depends on the actual retailer plan, smart-meter profile, solar generation, battery settings and equipment.

Explore Kratos battery storage solutions

Check your feed-in tariff value

Estimate your battery rebate

Contact Kratos Energy for a tailored assessment

A battery does not make every electricity tariff cheaper. The strongest combination is a correctly sized battery paired with a tariff that matches how your home actually uses energy.