The Big Switch: Australia’s Electric Future

by Saul Griffith

With low population density and extraordinary renewable resources, Australia has the easiest path of any developed country to zero emissions.

The first thing we will win is lower energy prices for all Australians. Driving our vehicles will be cheaper than it has ever been. Heating our homes and our showers will be cheaper than ever. Our electricity will be cheaper, too. The average household will probably save $5000 a year or more on energy and car expenses. There are two reasons for all this winning. One is the rooftop solar miracle. Through good policy and training programs, Australian rooftop solar is the cheapest electricity delivered to residential consumers in the world. This cheap solar energy will power more efficient electric vehicles (EVs), heat pumps and induction cooking, which is where the savings come from. It’s a simple recipe.

Looked at this way, roughly 22% of our emissions are for us, while 78% are for other people. Australians could reduce our domestic emissions to zero and still contribute heavily to climate change by continuing to export countless tonnes of fossil fuel. Cynical politicians argue that Australia should not have to cut emissions as much as other countries because these emissions aren’t ours and are actually in service of other economies. That is to admit we are arms dealers, selling the weapons (fossil fuels) that will be used against our children and future generations. What we’re missing is the opportunity that such an export-driven economy presents. In a world constrained by climate change, where we are one of only a handful of countries with ample, if not extraordinary, renewable-energy potential, the world will be hungry for decarbonised supply chains. Australia could still be first to offer zero-emission steel, aluminium, copper, other metals and agriculture.

If you put on a backpack full of all the fuels you needed to get through the day as an average Australian, it would weigh about 20 kilograms. Every day we burn those 20 kilograms of fossil fuels, which turn into 60 kilograms of CO2. In this day and age it is pretty hard to hide dead bodies, yet each of us basically hides a dead body-weight of carbon every day. It is amazing that we’ve hidden this from ourselves for so long . . . something sinister so easily achieved with a few swipes of a credit card and some auto-deposits.

We know that a good solar module can produce around 40–50 W per square metre (on average, all day, every day, through the whole year). To give us that comfortable 4000 to 5000 W electric lifestyle, some very basic maths tells us that each person needs the equivalent of 100 square metres of solar, a square ten metres on each side. If your population density is ten people per square kilometre, simple maths again tells us that around 1% of the land area of the country will need to be covered in renewables. If the population density is 100 people per square kilometre, you’ll need to cover 10% of the land. Most countries fall somewhere in between. To its great good fortune, Australia has 3.35 people per square kilometre. We need to cover less than one third of 1% of our land with renewable energy generation.

That is to say, we have solar in abundance. If we reduced our meat output by 20%, we could supply the whole world with energy on that rangeland. That idea might ruffle some feathers at the sausage sizzle, but it sure would beat 4°C of climate change.

Australian rooftop solar is the envy of the world. A small band of advocates on the south coast developed installation techniques in the early days that they translated into certification and training programs, which greased the skids for low-cost installation. The underlying modules cost 0.25 cents per watt, and wind up being roughly $1 per watt installed, which is a kind of magical number where the electricity costs around 5–7 cents per kWh – cheaper than the cost of transmission and distribution on a regular network.12 For the regular grid, if you include transmission costs, distribution and metering, the cost averages 12–13 cents per kWh, not including the cost of generating the electricity. This is momentous, because it means rooftop-generated electricity will now always be your cheapest option, even if nuclear fusion or some fantasy technology were free! And if batteries get to ten cents per kWh per cycle of storage, which is predicted as soon as 2024, then the economics will forever be in favour of installing as much local rooftop solar and as much battery storage as you can fit. Want to know why traditional energy suppliers are trying to slow this trend down? Because it kills the business model that was so profitable for so long. Yet some of the studies are still underestimating rooftop potential; here are three reasons why it’s even better than we think: (1) solar will be so cheap that we’ll start using north-facing vertical surfaces as well as our rooftops; (2) s...

In the US, 41% of all fresh water is used to cool nuclear, natural gas and coal power plants, and ultimately it is access to cooling water that limits the amount of nuclear power that can be deployed with current technology.

Why does cost matter? We don’t care so much about the cost per kWh as much as the cost per kWh cycle. This is the cost of the battery per cycle of storage, measured in cents per kWh. A Tesla Powerwall in 2021 comes with a ten-year, roughly 3700-cycle warranty. To achieve these long lifetimes, perhaps only 80% of the battery capacity is used. This makes the maths pretty simple – we divide the cost by the useful component of the battery, and divide that by the cycle life, to give us an estimate of the cost per kWh of storage: $1000 ÷ 0.8 ÷ 3700 ≈ 34 cents per kWh. This is why we are on the cusp of a revolution, but not quite there yet. At 34 cents per kWh, these storage costs make electricity very expensive. If you pair it with solar at six cents per kWh and you need to store half of the energy for later, the total cost of providing 24/7 energy will average out to 23 cents per kWh. This is almost but not quite competitive with the grid in most places. If you are in a remote area, it is likely to be economic.

When you burn a hydrocarbon fuel, the carbon atoms get oxidised with two oxygen atoms each, and the fuel is turned from a solid or a liquid into a gas – and gets about 5000 times bigger in the process. Even if you compress it back down into a liquid (which requires a huge amount of energy), the carbon still ends up three times bigger than when it came out of the ground as a fossil fuel. This means that to capture and store it, we would need to fill giant underground reservoirs, larger than the reservoirs it came out of in the first place. In its most recent report, the Intergovernmental Panel on Climate Change (IPCC) outlined the best-case scenario for CCS. It assumed burying huge amounts – 10 billion tonnes – a year of CO2. That is as many gigatonnes of stuff as the entire fossil-fuel industry currently rips out of the ground. It imagines an industry as large as the entire fossil-fuel industry to transport, process and bury CO2, and that this industry will somehow magically spring into being by 2050.

An electric car uses one third of the energy of a petrol car if the electric car is charged from wind or solar.

Australian houses are some of the worst in the world in their leakiness and poor insulation. Leakiness is all the holes and gaps between doors and window frames that allow cold or hot air to come into the home, requiring more energy to compensate in heating and cooling. Most of our homes have little or no insulation in their wall and roof cavities, and for the most part we don’t have double-glazed windows. All these simple building technologies would make the process of electrification and decarbonisation easier and cheaper. But insulating your home or closing the gaps economically is generally only something that happens when the home is newly built or undergoes a significant renovation. We should be promoting better building codes and standards, and they should apply not only to new builds but also to any retrofits.

Electric vehicles are approximately three and a half times more efficient in converting energy into motion than their internal combustion engine (ICE) counterparts. This is because there is no engine throwing away 80% or so of the energy in the fuel and converting it into heat. That heat loss is why you can throw a pot under the bonnet of a Land Rover and cook a stew as you drive – there is a ton of wasted energy.

The battery in an electric vehicle weighs more, but the motor is around 95% efficient, and the motor is lighter than the ICE engine. Most electric cars only have one ‘gear’ because the motor has high torque at all speeds. This eliminates the need for a transmission, which is another source of waste (and weight) with an ICE. Finally, with an electric car you can do regenerative braking, which captures quite a lot of the energy that would otherwise be warming your brake disks, and recharges the battery.

A gas stovetop has an approximate efficiency of 0.3, and an electric resistive stovetop has an efficiency of 0.7, or even higher for electric induction stovetops. The efficiency of heating by various means is illustrated in Figure 5.4. When you heat a pot of water with a natural-gas burner, 90% or more of the energy in the natural gas gets converted to heat, but 70% or so of that energy is lost because it heats the kitchen or room, not the water. You can feel this energy in the kitchen if you have been cooking for a while. You can feel the heat escaping from underneath the pot and under the sides. Electric resistance is better, because the heat is more directly transferred to the pot, and is often 70% efficient, twice as good as gas. Induction burners are the miracle new technology using the mysterious powers of magnetic fields to heat the pot, not the room. These are as high as 90% efficient at turning electricity into boiling water and in every way are a better cooking experience than cooking with gas – faster to heat, more control, easier to clean, cooler kitchen, lower burn risks for children, cleaner air for the whole family.

You can use these simple rules of thumb to advocate for electrification: 1.Making electricity with wind, solar or hydroelectricity takes one third of the energy of making electricity with fossil fuels, which waste two thirds of their energy content. 2.An electric vehicle, regardless of size or type, will use about one third as much energy as a fossil-fuel vehicle. 3.For low-temperature heat like domestic hot water and space heating, a heat pump needs only one third to one quarter of the energy of heating the same thing with fossil fuels. 4.For high-temperature heat, induction heating needs only half to three quarters of the energy that would be required using fossil fuels.

A friend and fellow Aussie expat, Andrew ‘Birchy’ Birch, wrote an influential piece about replicating the Australian model of rooftop solar in the US. He showed how most of the costs in the US are ‘soft costs’, or those not directly tied to hardware. These include permits inspection, overheads, transaction costs and sales. The Department of Energy agrees with him and its current $1 per watt target is focused on eliminating soft costs.

Here is the transformative point about rooftop solar. Because there are no transmission and distribution costs, it can be phenomenally cheap. Even if utility-scale generation were free, we don’t know how to transmit it and distribute it to you and sell it to you for less than the cost of rooftop solar. Transmission, distribution and billing costs are often more than half the cost of Australian electricity and add up to as much as 15 cents per kWh.

Households and investors will end up financing most of the cost of rewiring Australia, but governments have to help. They can do this in three significant ways: (1) stopping subsidising the problem (i.e. fossil fuels); (2) eliminating green tape to make the task cheaper; and (3) focusing government money on speeding this energy transition through pilots, incentives, rebates and subsidies that help the nascent market develop.