In the record-breaking heatwave that led up to the Black Saturday bushfires in Victoria, an estimated 374 people died due to the heat – before the fires even started. This is more than double the official figure of 173 deaths in the fires themselves.
Hot weather is a bugbear for many Australians. For the majority, living in temperate areas, summer heatwaves are a source of dread – and not just for the frail, or those in bushfire-prone areas.
It’s even become a topic of national debate – but not because of the early deaths of vulnerable people, or the sweaty discomfort. Rather, because so many people now have air-conditioners due to which electricity networks have implemented expensive network upgrades to cater to peak demand on a few hot days or weeks a year.
But what if those few days or weeks of summer peak load were not the main energy use peak? In fact, winter has by far the largest seasonal energy use across south-eastern Australia. In annual terms, heating energy demand is bigger than the demand for cooling energy by 80:1 in Victoria (and 10:1 nationally).
This doesn’t register in the peak energy use debate, partly because the individual daily peaks are lower – but also because consumers have become accustomed to paying for a parallel, redundant energy network that caters to heating: the gas network.
If this peak energy use debate could be compared to an iceberg, there’s a lot of issues hidden “underwater”. Australia, in general, uses far more energy than it needs to for basic services to buildings, and most of it is not summer cooling. Energy efficiency measures can take the edge off peak demand, and reduce much of that massive winter energy splurge.
Viewers who watched the ABC documentary 10 Bucks a Litre, narrated by Dick Smith, last week would have seen a fairly accurate (and typical) representation of a suburban household’s energy use. Unfortunately, the recommendations to save energy were underwhelming – shorter showers, and setting the AC thermostat a bit higher in summer was about as far as it went.
But energy efficiency measures can do much more than these trivial behaviour modifications: they can do some of the heavy lifting in decarbonising our energy supply. This idea is backed up by the new Zero Carbon Australia report released by Beyond Zero Emissions today, the ZCA Buildings Plan.
A simple upgrade to the building envelope – comprehensive insulation (walls and floors included), draft-sealing and double-glazing makes a large impact on energy use, and is a good first step.
But the key measure that’s not widely understood yet is replacing gas heaters (and electric radiators, as seen in 10 Bucks a Litre) with reverse-cycle air conditioners.
A lot of well-meaning people avoid using reverse-cycle air conditioners for heating, instead opting for those atrocious electric radiators, and gas heaters. Sometimes despite having a reverse-cycle air conditioner sitting there, only used for summer cooling.
This is partially a by-product of the discussion around air-conditioners driving peak demand, with many assuming they must be energy-guzzling monsters. But it’s wrong. Reverse-cycle air-conditioners can heat a room with a fraction of the energy that a five-star gas furnace (or an electric radiator) uses. The same technology (heat pumps) can also heat a hot water tank more efficiently than gas or electric alternatives.
To get houses to zero emissions, we have to get them to zero gas. Sounds like a big deal? Actually, the large factor by which heat pumps outperform gas appliances means it is already cheaper to run a heat pump unit (for water or space heating) than a brand new gas unit.
And comparing heat pump air conditioning to a brand new 5-star gas furnace doesn’t show the much greater energy savings that can be made from replacing old, even less efficient systems such as ducted gas heating.
The following chart illustrates the energy input (and waste) from a typical such system, as compared to the reverse-cycle air-conditioner that could replace it.
To go all the way, we can replace gas stoves with electric induction cooktops (which cook as fast as gas, but use much less energy). Then households can get rid of all the extra charges they pay to service a second, redundant energy network for gas, and use less energy to boot.
What will the coal-seam gas industry say about needing farmland for its gas wells, if Australia doesn’t need gas at all?
Gas prices are being pushed up steeply by exposure to international markets for our new LNG export capacity.
But the series of retrofit measures recommended in the Plan have a cost in the same order of magnitude as what would be spent on gas under business-as-usual.
If we’re going to be spending so many billions a year on our buildings and energy anyway, do we want to spend it on high energy bills, or on avoiding them with smarter measures? In this Plan the costs are upfront, but the economic benefits are clear – and economics doesn’t capture all of them.
To return to our starting point, rolling out the recommendations of this report would make houses more comfortable to live in, with flow-on benefits to health and well-being. If homes had full insulation and heat-pump air conditioners available for those heatwaves (as well as our regular cold winters), there wouldn’t just be lower peak energy use for cooling: how many early deaths from heat stress could have been avoided if homes had good insulation and air conditioners available?
This is the kind of benefit that is real and tangible, yet impossible to capture adequately in a dry cost-benefit analysis. Like many of the benefits of action to avoid disastrous climate change, most of the Plan’s recommendations are good ideas in and of themselves, and we hope they are taken up enthusiastically from the highest levels of government down to our streets and lounge-rooms, nationwide.
