What size battery do I need in Newcastle?

The single most common question we get, and the one most often answered badly. Battery size is not about your roof or your total consumption. It's about the power you draw when the sun isn't shining.

Start with your evening load

Look at your bill or, better, your smart meter data. Daytime consumption is largely covered by solar. The portion you use from late afternoon through to the next morning is what a battery displaces — and that's the number that sets the capacity.

The range most Newcastle homes land in

Most households we quote sit between 10 and 20 kWh. Smaller homes and couples often do well under that; families with ducted air-conditioning, a pool pump or an electric vehicle push above it.

Why bigger isn't better

A battery only pays for itself on the energy it cycles. Capacity that sits unused every night is capital doing nothing. Oversizing is the most common way people end up disappointed with a battery's payback.

Things that change the answer

• An electric vehicle, now or planned — charging at home shifts the calculation considerably.
• Your energy plan: free or very cheap power windows make a fast-charging battery more valuable.
• Whether you want backup, and how much of the house you want backed up.
• Whether you're likely to add solar capacity later.

Sizing for the rebate tiers

Incentive thresholds mean certain capacities are better value than others. Some systems, like the AlphaESS SMILE, use module sizes chosen to line up with those tiers. It's worth knowing where the thresholds sit before settling on a number.

Our estimator gives an indicative size in a couple of minutes. We confirm it against your actual bills before quoting — it's a starting point, not a promise.