If you’ve ever looked at your energy bill and wondered why the cost of your electricity changes depending on the time of day, you’re not alone. The idea of paying different rates at different times can feel a bit mysterious. But understanding it can help you take control of your bills and your environmental impact.
In Australia, our electricity use isn’t steady throughout the day. Some times of the day, called peak electricity hours, see huge demand, putting extra pressure on the grid. At other times, known as off-peak electricity times, demand drops, prices fall, and renewable energy is often more abundant.
A time of use tariff zooms way out on what’s happening in the market, showing only the broadest trends. With Amber, you can see the market changing in detail. Read on to understand what peak and off-peak really mean.
Why the time of day matters for electricity prices
The electricity system has to balance supply and demand in real time. When demand spikes - for example, on a hot summer evening when everyone’s running air conditioning - prices go up. When demand drops, prices fall.
This is where time of use tariffs come in. If you’re on a plan like this, the price you pay changes depending on the time of day:
- Peak - the most expensive times, when demand is highest
- Off-peak - the cheapest times, when demand is lowest
- Shoulder - shoulder electricity times sit in between peak and off-peak, at a mid-range price
If you’re on a single rate tariff, you’ll pay the same price 24/7, regardless of demand. That’s simpler, but it means you can’t take advantage of cheaper times. Amber works differently - we give you direct access to real-time wholesale prices that reflect what’s actually happening in the market.
What is off-peak electricity?
Off-peak electricity times are periods when demand for power is lower and wholesale prices tend to be cheaper. These can be late at night, in the middle of the day, or on weekends - depending on your network and meter.
In earlier times, coal stations delivered the bulk of Australia's power, and those plants were designed to run 24/7 (at least while they were still within their planned lifetime). Overnight, demand fell but generation kept humming - so electricity was plentiful and cheaper.
But here’s the important part: off-peak doesn’t always mean “middle of the night” anymore. In solar-heavy states, prices can actually drop during the day when rooftop solar is flooding the grid with renewable energy. That’s why understanding your local patterns is key.
What is peak electricity?
Peak electricity hours are the times of day when demand is highest and the grid is under the most pressure. This often falls in the early evening - when people arrive home from work, start cooking dinner, and switch on appliances. It’s also when the sun has set, so solar generation has dropped.
Meeting this demand often means switching on more expensive (and usually more polluting) generation sources. By avoiding peak hours, you’re not just saving money - you’re reducing reliance on those sources.
Why prices change - and why the long view matters
In Amber’s model, you’re buying your power at the real-time wholesale price - the same price retailers pay. These prices move up and down throughout the day and across the seasons, influenced by things like:
- Supply and demand - high demand pushes prices up, low demand pushes them down
- Weather - heatwaves, cold snaps, and even mild sunny days can all shift demand and supply
- Renewable availability - solar and wind can flood the grid with cheap, clean energy or dip when the sun sets and wind slows
That means some months you might pay more, and some months you’ll pay less. What matters is the long-term view, and this is where the Amber wholesale model shines. Over the course of a year, you have the ability to come out ahead by using more power when it’s cheap and green, and less when it’s expensive and fossil-fuel heavy.
The renewable energy connection
At Amber, shifting your energy use isn’t just about finding cheap electricity times - it’s about using power when renewables are abundant. This could be:
- Midday solar surges - tapping into excess rooftop and utility-scale solar
- Windy nights - when wind generation can push prices down
- Mild weather days - when neither heating nor cooling drives huge demand
The more we collectively move our energy use to these windows, the more renewable energy we use and the faster Australia can transition to 100% clean energy.
A household example
Let’s say you have a dishwasher, washing machine, and an electric vehicle.
If you run them all during peak hours, you’re paying more and likely drawing on dirtier energy. But if you shift those loads to midday (when the sun’s out) or a windy off-peak period overnight, you can:
- Save significantly on your bill
- Use more renewable energy
- Help reduce pressure on the grid
Amber’s SmartShift automation takes this a step further by moving your battery and EV charging to the best times automatically - no manual juggling required.
How Amber helps you take advantage
With Amber’s wholesale pricing, you can see real-time prices in the app (not just set peak/off-peak windows) and plan your usage accordingly. You’ll know exactly when power is cheapest and greenest, so you can shift your usage and exports for maximum benefit.
This isn’t just about saving on your own bill. It’s about changing how energy is used across the country - putting the power back in customers’ hands and making the most of renewables when they’re available.
