Spring brings a lot more solar into Australia’s electricity grid. As the days get longer and rooftop systems generate more power, wholesale electricity prices tend to fall during the day, often into negative territory.
Later in the day, the picture changes. Solar generation drops away as the sun sets, while spring is also a common time for generators to schedule maintenance. That can mean tighter supply and higher wholesale prices in the evening.
For households with a battery, the gap between those daytime and evening prices can create more opportunities to make use of the energy sitting on the wall.
What happens to electricity prices in spring
Australia’s rooftop solar systems produce a huge amount of electricity during the day. In spring, increasing solar generation adds even more cheap energy to the grid, pushing wholesale prices down when solar output is high.
At the same time, generators tend to schedule maintenance during spring, when electricity demand is typically lower than during winter and summer. Some of that generation is therefore unavailable later in the day, just as rooftop solar starts dropping away.
The result can be very different wholesale prices within the space of a few hours: cheap or negative electricity during the day, followed by higher prices in the evening.
Most households don’t see those movements directly. On a standard retail plan, the price you pay for electricity is fixed or close to it, and exports are generally paid at a set feed-in tariff.
That also limits what a battery can do with those changes in the market.
How most home batteries work
A lot of home batteries run in self-consumption mode. Your solar charges the battery during the day, then your home uses that stored energy later instead of buying electricity from the grid.
That can reduce your electricity bill. But the battery is responding to your solar generation and household consumption, rather than the wholesale value of electricity at different times of day.
The feed-in tariff matters too. If your electricity plan pays around 4 cents per kilowatt hour for exports, there may be little reason to deliberately keep energy available to sell back to the grid. Once the battery has enough stored energy to cover your household usage, there isn’t much more for it to do.
Spring makes that limitation more noticeable because the difference between daytime and evening wholesale prices can become larger.
What changes with wholesale pricing
The size of the price difference matters to a battery. Cheap or negative daytime prices create an opportunity to charge, while higher evening prices increase the value of avoiding grid consumption or exporting stored energy.
To make use of that difference, the battery needs to be connected to an electricity plan that exposes it to wholesale prices.
Amber customers pay the wholesale price for the electricity they buy and receive the wholesale price for the electricity they export, with no markup in either direction. Amber’s margin comes from a flat monthly subscription.
For battery customers, SmartShift monitors wholesale prices and automates when the battery charges and discharges. It can charge when electricity is cheap or negatively priced, then use or export that stored energy when prices are higher.
During wholesale price spikes, export prices can reach up to $19 per kilowatt hour. Amber customers keep 100 per cent of that wholesale export price.
This gives the battery another way to create value beyond storing excess rooftop solar for use later in the day. The amount of energy in the battery can be managed according to what electricity is worth at different times.
Spring tends to create more of those price differences, which gives SmartShift more to work with.
What this can look like for a battery owner
Before switching to Amber, Anthony and his family were exporting 70–80 kWh of solar to the grid each day in summer and getting 5c/kWh for it. At night, they were paying 35c/kWh to buy electricity back from the grid.
That experience was part of what prompted Anthony to install a battery and eventually switch to Amber.
Today, his household earns between $1,200 and $1,600 a year through Amber. During one wholesale price spike, they earned $375 in a single day by exporting energy from their battery back to the grid.
Over two and a half years, Anthony estimates the household is around $10,000 better off through a combination of avoided electricity bills and earnings.
His experience shows why the electricity plan behind a battery matters. Storing solar for later use can reduce how much electricity you need to buy from the grid. Access to wholesale prices gives the battery another option: exporting stored energy when it’s worth more.
Getting more from a battery this spring
Spring is a useful time to look at how your battery is being used.
More rooftop solar can push wholesale prices down during the day, while tighter evening conditions can push them back up. A battery running in self-consumption mode will continue charging from solar and supplying the home as usual, regardless of those movements.
A battery connected to wholesale prices can respond to them.
If you already have a battery, it’s worth looking beyond how much energy it stores and considering what your electricity plan allows it to do with that energy.
And if you’re considering buying a battery this spring, the electricity plan it will run on is worth factoring into the decision from the start.
Want to see what your battery could be doing this spring? Get a quote with Amber and find out.
