CHAPTER 3: WHY GET OFF GAS
The cost difference of getting off gas
Along with the growth of renewables, another key reason electrification can reduce emissions and benefit households is that modern electric appliances are generally much more efficient than equivalent gas appliances.
Induction cooktops are more than twice as efficient as gas cooktops, reverse-cycle air-conditioners are more than three times as efficient as gas heaters, and heat-pump water heaters are generally four to five times as efficient as gas water heaters.
Modelling undertaken last year by Renew using their energy simulation platform Sunulator, has demonstrated that efficient, all-electric homes already save money. Annual bills in 2022 for a 7-Star all-electric home with solar were 69%-83% less than bills for a 3-Star home with gas appliances and no solar, depending on location. Savings on average per year for ditching the old gas heater in favour of a split system/reverse cycle air-conditioner (without solar panels) ranges from $256 in Perth, $440 in Adelaide, to $546 in Canberra and $409 in Melbourne. Heating a space with an efficient reverse-cycle air conditioner was found to be approximately four times more efficient than using ducted gas.
Likewise, when thinking about water heating electrification, on the existing electricity grid, the cost is roughly halved when using a heat pump compared to a natural gas water heater. With the additional benefit of financed solar panels and a home battery providing the energy, the costs fall even lower to around three times less than gas heating costs.
McCully, by Brave New Eco is a featured home as part of Sustainable House Day. The gas kitchen has been converted to electric using heat-pump hot water and induction cooking, running on renewable energy. Read more at the Sustainable House Day website.
In terms of payback, there is an enormous variation in the types of appliances that people have, as well as those that are available to purchase, and what their energy rating is. The difference between lower-priced electric appliances for heat pump hot water, reverse cycle air conditioner and induction stoves ($7,818) and higher end appliances ($14,936). Both scenarios included installation costs and $3,000 for electrical upgrades and other costs. The payback period ranged for low-priced appliances from 5 years in Hobart and Canberra to 15 years in Perth and Sydney, while the higher-priced appliances were in the order of 8-10 years for most cities and 12, 16 and 19 years for Melbourne, Perth and Sydney respectively.