Want to fully electrify your house? Don’t start with a battery

BeyondImages/Getty Many Australians want to go fully electric.

But it’s often hard to know where to start.

Solar? A home battery? Or quitting gas? To find the best way to make the shift, we modelled three pathways for a three-bedroom house in Melbourne’s western suburbs.

These pathways show it’s important to do things in the right order.

It’s best to start by lowering energy demand through better insulation and stopping draughts, and then switch from gas heating to an efficient reverse-cycle air conditioner.

Home batteries should ideally be done last.

What did we do? We used benchmark data to model a household with ducted gas heating, gas hot water and cooktop, common electric household appliances and a petrol car.

Each year this household uses 5,300 kilowatt-hours of electricity, just under 50 gigajoules of gas, and about 1,230 litres of petrol (to drive 11,100 kilometres).

This costs A$2,477 for electricity, $1,494 for gas and $2,255 for petrol.

Total energy costs are $6,226 a year.

We modelled replacing these with a 10-kilowatt ducted reverse-cycle air conditioner, a hot water heat pump and an induction cooktop.

We model two further options: one where the household switches to a mid-range EV with a battery of about 60kWh and another where the household keeps its petrol car.

Which pathway? We tested three pathways to going electric.

These don’t include rebates or the cost of the EV.