Want to get rid of the gas bill - Here's how

A range of academic analyses have now demonstrated that a transition from coal to gas is not a sensible approach to avoid dangerous global warming.

It doesn't reduce emissions by enough to keep us within the 2 degree carbon budget, and Cornell University research indicates that methane leakage can make the problem worse rather than better.

In addition it is likely to cost us more than moving straight to renewables and more energy efficient electric appliances, as shown by analysis from the ATA and University of Queensland and University of NSW.

Thanks to major gas price rises and advances in the efficiency of electrical appliances, gas is now a more expensive service than electricity. 

Heating with a gas ducted system costs about 16c/kWh (once you take into account flue inefficiency, ducting losses and pressure mismatch/equalization losses). While heating with a Daikin Ururu Sarara humidifying reverse cycle air conditioner in Melbourne costs around 4c/kWh.  And (these days) a gas hot water service even costs a little more than a heat pump hot water service (electric hot water was horrendously expensive before heat pumps).  In addition these disparities are likely to widen over time.  

Many of my friends have now started or are just completing their journey to get off gas and many more are wanting to learn how.

Here's how and the potential pitfalls you need to avoid.

Cooking (without) Gas.

It's easy to replace your gas cooktop with induction electric.  It's really important (for budding Master Chefs) to buy an electric INDUCTION cooktop as regular electric is too slow to respond and doesn't provide the same level of cooking experience as induction cooking.

The consumer group Choice note that induction cooktops heat food far faster, “the approximate time to boil 1 litre of water on a gas cooktop is eight minutes, on radiant ceramic six minutes, and on an induction cooktop just two minutes.” In addition they note, “when you change the temperature, this change is reflected immediately”. So if time is important to you and you also like precise control then induction is for you.  

Induction cooktops range in cost from $500-$4000. Note that Choice found a number of cheap models still scored well on performance and their cost is dropping rapidly.

If you're shopping at the cheaper Chinese end of the market make sure that the hob size is as wide as your pots. Some very cheap units have a very small heating zone, as an example, a friend recently got caught out here when he purchased a 2 heating zone unit for $200.

Whatever you do, don't let your electrician try to convince you that you need a supply upgrade (an unnecessary larger capacity connection to the grid).  An efficient all-electric house should work fine on a 7.5kW grid connection, and the smallest connections around are usually about 35Amps (8.4kW). 

In addition induction cooktops require cookware with a ferrous base to work properly - copper, glass and aluminium cookware won't work. You can test whether the cookware is suitable by checking whether a magnet sticks to the base of pot or pan.  

Efficient Electric Heating

Newly installed gas ducted heaters lose about 50% of their heat energy (measured at the meter) to the atmosphere due to flue inefficiency, ducting losses and pressure equalization mismatch.

Whereas small, modular mini split system air conditioners running in reverse cycle (heating mode) gain 500-600% of their delivered energy from the atmosphere.  

Also of note is that a Daikin Ururu Sarara has humidity control which can allow you to feel comfortable at a lower temperature set point e.g. 22degrees @ 50% controlled humidity versus 28 degrees @ 20% uncontrolled humidity. This can save up to a further 30% on heating bills.  No other heater on the Australian market (competitors have units in Japan) can achieve this level of direct humidity control.  2 to 4 Daikin Ururu Sarara's will adequately heat most houses and I recommend the smallest units (your air conditioning contractor will probably try to upsell you to a bigger unit, but that isn't necessary).

Furthermore it is fine to run a couple of Ururu Sarara's off a regular existing household general power point supply circuit, as they only consume about 400Watts in cooling mode and 600Watts in heating mode.  Avoiding the requirement for additional unnecessary circuits saves more money on installation, and lets you access a quicker financial return on your investment.

Electric Hot Water

Japan has pioneered the “Eco-cute” range of high performance CO2 heat pumps.  There is only one such unit that has made it to the Australian market which is the Sanden CO2 heat pump.  A Sanden CO2 heatpump can be installed to replace your gas storage, gas instantaneous or existing electric-resistance water heater.

Building Envelope.

Now that you've removed the danger of carbon monoxide poisoning from your home, by getting rid of gas, it's safe to significantly seal-up your house.  Organising a contractor to air pressure test and air seal your building will save significantly on heating and cooling energy costs. It can also  prolong the life of your newly installed reverse cycle air conditioners by not working them so hard.

Air sealing a house that formerly had gas ducted heating and/or evaporative cooling involves a primary focus on the vents in the ceiling and/or floors.  They are usually installed poorly and leak around the edges.  These must be completely sealed to remove the very costly thermal chimney effect that ducting introduces to a legacy gas heated house.

Dovetailing with an air-sealing regime is the requirement to move around the house with a thermal imaging camera to identify sources of heat leakage.  This is usually done at the same time as the air pressurisation-testing because the extra pressure acts to exaggerate heat leakage, making it easier to identify locations with missing insulation.  Best practice roof insulation is usually to have bulk batts combined with foil insulation. This can be patched up or installed depending on what the thermal imaging camera finds. Note:  always have the power turned off while working in the roof space.

Wall insulation is then either replaced by injecting expanding foams into the walls and sub floors by drilling a series of pilot access holes through exterior bricks/boards, or replacing plaster from the interior and placing batts in the walls or removing exterior boards for access.

That is pretty much it.

You are free of gas forever, you have lower (or no energy costs if you install solar PV), and your CO2 emissions are close to saintly.  All while you benefit from the comfort and convenience of living in a state-of-the-art, all-electric house.

Matthew Wright is executive director of Zero Emissions Australia, technical director at Efficiency Matrix and resident columnist at Climate Spectator.