TL;DR: Time-of-use billing charges a different rate depending on when you draw power. In NSW that means peak in the late afternoon and evening, shoulder either side of it, and off-peak overnight. For a solar household the gap between those rates decides whether your system pays for itself in six years or ten.
What Are Time-of-Use Rates?
Three prices for the same kilowatt-hour, applied by the clock.
Peak covers the hours when everyone is home and the grid is under load. Shoulder sits either side of it. Off-peak is overnight, when demand collapses.
On a flat tariff, the timing of your consumption is irrelevant. On time-of-use it is half the equation. Running the dishwasher at 6pm can cost three times what the same cycle costs at 10pm.
Why Retailers Moved Away From Flat Rates
Electricity costs more to supply at 6pm than at 3am, and flat pricing hid that from customers entirely.
Most new NSW connections now default to time-of-use, and many existing customers were shifted across when their meter was replaced. Plenty found out on a bill rather than in a phone call, which is why checking your tariff after any meter work is worth five minutes.
The Smart Meter Requirement
Time-of-use pricing needs interval data, so it needs a smart meter.
A smart meter records consumption in 30-minute blocks and sends it to your retailer. An old accumulation meter shows one number for the quarter, which supports exactly one pricing structure: a flat rate. That relationship is covered in more detail in our guide to smart meters and time-of-use tariffs.
Finding Out What You Are Actually On
Your bill names the tariff, usually near the usage breakdown. If you see separate line items labelled peak, shoulder and off-peak with different rates against each, you are on time-of-use. A single usage rate for the whole quarter means you are still on a flat tariff.
The bill also names your distributor. In Sydney that is Ausgrid or Endeavour Energy; regional NSW is Essential Energy. The distributor sets the window boundaries your retailer prices against, which is why two customers with the same retailer in different suburbs can have different peak hours.
When Do Peak, Shoulder and Off-Peak Apply in NSW?
The windows vary by retailer and network area, but the shape is consistent.
Peak is typically weekdays from 2pm to 8pm, or 5pm to 9pm on some plans. Expect 40-50c/kWh.
Shoulder covers weekday mornings from around 7am to 2pm, the late evening from 8pm to 10pm, and much of the weekend daytime. Expect 20-30c/kWh.
Off-peak runs overnight, roughly 10pm to 7am, and often all weekend. Expect 10-15c/kWh.
Check your own plan rather than these ranges. Retailers move the boundaries, and a peak window that opens at 2pm instead of 5pm costs an afternoon household real money.
Peak Is Where the Damage Happens
At 50c/kWh, an hour of air conditioning plus an electric oven can cost more than the entire overnight period.
For a solar household this is the window that matters most, because it opens while your panels are still producing and closes long after they have stopped. Everything you can either self-consume or shift out of it comes straight off the bill.
Weekends are usually treated as shoulder or off-peak across the whole day, which is worth knowing before you reorganise your washing around a peak window that does not apply on a Saturday.
Shoulder Is the Useful Middle
Shoulder rates are not cheap, but they are roughly half of peak.
The practical use is for loads that cannot wait until midnight. A wash cycle at 9am or 9pm lands in shoulder rather than peak, and for most households that is easier to sustain than trying to run everything overnight.
Off-Peak Is Where the Timers Go
At 10-15c/kWh, off-peak is the cheapest grid power you will get.
Dishwashers, washing machines and EV chargers all have delayed-start functions. Set them once and the saving is permanent. If you have a battery, off-peak is also when it makes sense to charge from the grid on days your solar has not managed to fill it.
Hot water is often billed separately again, on a controlled load tariff that runs overnight at a lower rate than even off-peak. If your storage tank is on controlled load, leave it there. Moving it onto the main circuit so it heats during the day is common advice that only works if your solar reliably covers the whole heating cycle.
Why Time-of-Use Matters More If You Have Solar
Because the value of a self-consumed kilowatt-hour is not fixed. It equals whatever you would otherwise have paid at that moment.
Use your own generation during a 50c/kWh peak and you have saved 50c. Use it during a 15c/kWh off-peak window and you have saved 15c. Export it and you earn a feed-in tariff of 5-8c/kWh.
That spread is the whole argument. The same solar panels producing the same output can return wildly different amounts depending on what you do with the power.
Self-Consumption Beats Export, Heavily
Say your system puts out 5kWh during a peak window.
Use it in the house and you avoid $2.50 of imported power. Export it at 7c/kWh and you earn 35c.
Seven times the return, for the same electricity. That is why shifting heavy loads onto the middle of the day matters more on time-of-use than it ever did on a flat rate.
When Exporting Is Still the Right Call
If you genuinely cannot use the power, export it. A feed-in credit beats nothing.
The judgement only gets interesting at the margins. With a 7c/kWh feed-in and a 10c/kWh off-peak import rate, exporting now and importing later costs 3c per unit, which is trivial. Against a 45c/kWh peak rate it is not trivial at all, and closing that gap is what a battery is for.
Watch for Demand Charges
Some NSW plans add a demand charge on top of time-of-use. It bills you on your single highest half-hour of consumption during the month, not your total.
One evening where the air conditioner, oven and dryer all run together can set the charge for the entire billing period. If your bill carries a line measured in kW rather than kWh, you are on one of these, and staggering large appliances matters more than the total you use.
How to Actually Cut Your Bill
Two levers: move your consumption, or store your generation.
Shifting Load
Put the dishwasher, washing machine and dryer on the middle of the day or the overnight window. Most have a delay timer.
Set the pool pump to run while your solar panels are generating rather than in the evening. Pre-cool the house from 1pm rather than switching the air conditioner on at 5pm, when both the outside temperature and the tariff are at their worst.
None of this is dramatic. It is a handful of timer settings that keep paying every quarter.
Adding Storage
Battery storage is what lets you consume your midday generation at 6pm.
Charge it from surplus solar during the day, discharge it through the peak window. Instead of exporting at 7c and buying back at 50c, you keep the difference.
Most modern systems can also charge from the grid during off-peak and discharge during peak, which earns its keep on overcast days when there is no surplus to store. Whether that stacks up depends on your specific rates, but a 35c spread between off-peak and peak makes it worth configuring.
Review the Plan Once a Year
Peak windows and rates both move. A plan that suited your household two years ago may now be charging peak rates across hours you are reliably home.
Your retailer holds the interval data to check it, and will usually run the comparison on request. Compare on total annual cost using your own usage, not on the headline peak rate.
Key Takeaways
- NSW peak is usually weekdays 2pm-8pm at 40-50c/kWh, shoulder 20-30c/kWh, off-peak overnight at 10-15c/kWh.
- Check your actual plan. Retailers set different windows, and when peak opens matters more than the rate itself.
- A self-consumed kilowatt-hour is worth whatever you avoid paying, so solar used during peak is worth roughly seven times the same power exported.
- Timers on the dishwasher, washing machine and pool pump are the cheapest saving available.
- A battery converts cheap midday power into expensive evening power, which is where time-of-use pays a solar household best.
Read More
For an overview, check out our master guide: Read the Full Guide Here.
