Faster, easier, cheaper - getting to net zero using energy efficiency measures

With delays getting some of the big renewable energy projects off the ground to decarbonise the electricity grid, some energy experts think net zero can happen faster if more households and businesses install solar and batteries.

Australia’s has an estimated 11 million homes that produce more than 10 per cent of our total emissions and use more than 25 per cent of the electricity.

And we’ve already shown in Australia that the individual actions of thousands of householders can make a big difference – we have the highest uptake of rooftop solar in the world, which is helping kick coal out of the grid.

Gabrielle Kuiper, an independent specialist on distributed energy resources, and consultant to the Super Power Institute and Smart Energy Council, says, “if you can get the batteries and the flexible storage behind the meter [in the home] then you can soak up the solar in the day … and yield a 92% reduction in that peak [grid] demand”.  

However, other energy experts are more circumspect about relying on householders to decarbonise the grid.

“Over relying on every single house having to have all of their energy needs met on site is a much more expensive way,” Rob Murray-Leach, the Head of Market Transformation at the Energy Efficiency Council told the SwitchedOn podcast.

“Let's move away from the sort of Ayn Rand model of clean energy, towards more of a community based one where we're sharing solar resources, and we're sharing wind resources amongst the community,” says Murray-Leach, who thinks we need more community energy resources.

Like all renewable energy experts, Murray-Leach wants the whole grid to be clean, and affordable, as soon as possible, but he thinks households can help make this happen if they focus on energy efficiency measures.

Until recently energy efficiency measures that reduce the amount of energy we use – insulation, efficient appliances - have “done the heavy lifting” to reduce our greenhouse gas emissions, says Murray-Leach.

But as we get more renewables into the system, which is now happening, renewables become the major player in reducing emissions, and energy efficiency measures shift to a support role, “enabling us to get to renewables faster and cheaper.”

“It makes it easier and faster and cheaper to electrify our homes and ensure that our system, our electricity grid moves to 100% renewables as quickly as possible.”

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Efficient homes good for the grid

The way Murray-Leach explains it is that even houses with solar panels will have to draw extra power from a dirty grid if they are not energy efficient.

For instance, households with solar systems in places like Melbourne, Canberra, Adelaide or Tasmania, have dramatically lower solar production in winter.

If you also have a thermally inefficient house – drafty, no insulation - and inefficient appliances, “you're going to be losing a ton of heat out the walls and the ceiling of your uninsulated leaky home, which means you're going to need to draw a lot of energy from the grid at times when there isn't lots of renewables in there.”

Murray-Leach argues that this not only has an impact on the comfort of our homes but also on the decarbonisation of the grid. Houses will have to draw more from the grid, “using the last remaining bits of coal and gas fired generation on the grid, and it also means we have to keep [fossil fuel plants] operating for much longer.”

Murray-Leach says if we can reduce our energy needs during times when we're not producing much energy from renewable sources, by making our homes more energy efficient, and using efficient electric appliances, then we can reduce more of our carbon emissions.  

Households that invest in rooftop solar and batteries, who don’t do things efficiently, will also end up investing in a lot more renewables to ensure they have enough energy for winter, but this will mean massively over producing for what they need in summer.

Whilst he acknowledges there is no renewable energy system which doesn't over produce energy for parts of the year - and some excess is not a massive problem - what is a problem is the poor quality of our housing in Australia because they use more energy.  

Australian houses have an average energy rating of between 1.5 and 2.5 stars (out of 10). We don’t insulate properly, we use inefficient gas and electrical appliances, etc.

So when we make decisions about how much solar to put on the roof, or how many batteries to install, we’re probably basing that on the additional power our poor quality housing needs to achieve a level of comfort.

“Saving energy in the middle of winter or in the evening is really going to make a big difference for households and reduce the amount of batteries that they need and reduce the amount they need to draw from the grid.”

“If you build your home better, or you renovate your home, and do a draft proofing solution, not only is it cheaper to run and uses a lot less energy, but fundamentally, it's just a much more comfortable home.”

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Minimum energy efficiency standards

Compared to the average Australian home, houses in many parts of Europe are much more energy efficient and comfortable.

There’s solid evidence that minimum energy standards have reduced energy use in Europe. Energy standards indicate how efficient homes are and provide a clear direction of what needs to be done to improve the comfort and performance of a home, especially when people buy or rent.  

“In South Australia, there is 20% higher rate of mortality from hypothermia than Sweden. This is a country that regularly gets down to minus 20,” says Murray-Leach.

“But also in Sweden, if you die from hypothermia, you generally fell asleep drunk in the street, in the snow, or ice fishing and you fall in. Whereas in Adelaide, if you die from hypothermia, you were generally in your own home.”

Except for the ACT, where it became mandatory to declare the energy ratings for homes in 2010 when they are leased or sold, we don’t yet have mandatory ratings for residential buildings, despite years of advocacy trying to get them.

“Canberra is the only place in the country where new homes are built significantly above the minimum standard, and you see quite a good rate of retrofitting of existing homes,” says Murray-Leach.

Mandatory energy ratings were introduced for commercial buildings in Australia in 2010. This made it compulsory to disclose a buildings energy rating when an office over a certain size was leased or rented.

“In the last 10 years, the energy use per square meter in offices has fallen by pretty close to 50%, which is mind blowing.”

The property industry initially argued against the introduction of mandatory ratings, but 4 years later they opposed attempts by Tony Abbott’s government to abolish them, “because they realised how beneficial it was to the sector.”

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You can hear the full interview with Rob Murray-Leach on the SwitchedOn Australia podcast here.