A Beginner’s Guide To Home Batteries
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The home of James Goodlet and Claire Thomas of Altereco Design is an all-electric, energy-efficient home with a generous solar array and a home battery.
A home battery can significantly reduce how much power you need to buy from the grid, and ultimately lower your household power bills.
A household with both solar and battery storage enables maximum control of energy use.
With rebates available via the Government’s Cheaper Home Batteries Program, and features that allow you to store your solar energy to use when you most need it, investing in a battery has never looked so good. But getting started in this space can feel overwhelming, so to break it down, we’ve answered your frequently asked questions, in partnership wth AGL.
Why should I consider investing in a home battery?
For those living in a home with a solar power system, a home battery allows you to store excess solar energy generated during the day, to be used later when the sun isn’t shining. This can significantly reduce how much power you need to buy from an energy provider, and help avoid peak-time electricity prices.
‘Use your battery during high-price periods and charge from solar or off-peak grid power when rates are lower,’ advises Hilton Garcia, Product Lead in Home Electrification at AGL.
With the right energy plan, such as AGL’s Battery Rewards Plan, households can earn bill credits by exporting stored energy back to the grid during peak times to earn higher feed-in tariffs. You can also increase your savings further by adding a Virtual Power Plant (VPP) to your energy plan. More on those below.
A household with both battery storage and solar power has maximum control of their electricity use. ‘By storing your own solar, you’re less exposed to price changes and grid constraints,’ says Hilton. ‘Run flexible loads (dishwasher, washing machine, EV charging) when solar is abundant or off-peak, leaving more stored energy to use or export at peak times.’
Most households with a solar system but no battery use around 25% of the energy they generate, while systems with a solar and a battery use around 50-60%.
What size solar and battery system is best for my home?
Every household is different, but some common starting points are:
Small household (1-2 people): around 3-6 kW solar system and a 6-12 kWh battery
Medium household (3-4 people): around 6-8 kW solar system and a 12-20 kWh battery
Large/high-usage households (those with an electric vehicle, pool, etc): around 7-15+ kW solar system and a 16-30+ kWh battery
The best technology for you depends on your roof space, budget, when you use most power, and your goals — whether that’s having less reliance on the grid, or maximising feed-in tariffs, for example.
AGL’s Electrify Now™ tool provides users with personalised info on the savings they’re likely to achieve with solar and a battery, based on their existing power bills and usage habits. The tool also outlines estimated upfront costs, payback periods, available rebates, and can connect you with trusted installers in your local area.
How much does a home battery cost, and are they decreasing?
Battery prices have generally trended down over the past decade, says Hilton, while their capacity and performance has improved.
Rebates and incentives such as the Australian government’s Cheaper Home Batteries Program can save eligible households thousands of dollars (around 30% on the upfront cost) when purchasing a small-scale battery system connected to a new or existing solar system. Find out more about the Cheaper Home Batteries Program here.
Home batteries available in Australia start at around $4,000, and for a typical Australian home, a battery costs between $10,000 to $13,000, according to independent climate organisation Climate Council.
Consumers can expect to achieve ‘payback’ across their battery’s life by effectively managing their grid electricity, and maximising earning potential with AGL’S Battery Rewards Plan.
How can I maximise my battery’s earning potential?
In addition to reducing overall household energy consumption, a battery can earn households extra rewards by enabling access to peak feed-in tariffs. Joining a Virtual Power Plant can also boost your savings.
A feed-in tariff (FiT) is the rate your electricity retailer pays you for each kilowatt-hour (kWh) of electricity exported from your solar battery system back to the grid. The base rate per kWh is set by your retailer and influenced by state regulations, but some retailers offer additional incentives, such as AGL’s Battery Rewards Plan, which provides a higher FiT during peak times (5pm – 9pm), on top of your standard state-based feed-in tariff. Find out more about solar feed-in tariffs here.
A Virtual Power Plant (VPP) is a network of connected home batteries that can be coordinated to act like a single large power plant. When the grid is under pressure, such as during heatwaves, households with participating batteries can provide support to the grid, often in exchange for bill credits or discounts.
The benefits of joining AGL’s VPP include ongoing quarterly credits just for staying connected, on top of event-based credits. Once connected, AGL manages VPP events automatically, and you can track activity and estimated savings via the AGL app.