Clean energy: the state of play

The key information is that Australia's total fossil fuel consumption that year was 5796 PJ. Of that, 2222.4 PJ or 38% was burnt in power stations to produce 763.2 PJ thermal electricity. The rest, 62%, went elsewhere.

These numbers point unequivocally to the significance of "% renewables". If all electricity that year came from renewables it would properly be described as "100% renewables". Fossil fuel consumption would be lowered by 2222.4 PJ, the bulk would remain.

"100% renewables" does not mean the end of fossil fuels. Confusion on this matter is common.

This reasoning leads to another significant conclusion. Take the year quoted above as the example. Renewables generation of 950.5 PJ electrical energy, "100% renewables", would displace 38% of total fossil fuel consumption. This number immediately suggests a way of estimating how much clean electricity might be needed to get rid of all fossil fuels, including the other 62%.

1/0.38 = 2.63. As 950.5 PJ clean electricity would displace 38% of fossil fuel, it is a small step to suggest that 2.63 times that amount might replace all fossil fuel. So for this example 2.63 X 950.5 = 2500 PJ might constitute enough clean electricity to eliminate all fossil fuel consumption (in that sample year). In the current terminology that would translate to "263% renewables".

There are many assumptions implicit in the above reasoning and "260%" (rounded) can be only a rough estimate. In my view there is no possibility that it can be less than 260% and a strong likelihood it is higher. But 2500 PJ is a reasonable start for assessing adequacy of prevailing renewables growth rates in reaching targets.

The key to arriving at more reliable target estimates is greater knowledge of what is involved in "electrifying everything", including detailed process flow charts and electrical energy consumptions. That's a huge challenge. Anyone who thinks otherwise should talk to experienced process development engineers. Ideas are always plentiful; turning them into viable industrial technologies is a long, risky, expensive process.

Targets and growth rates: the state of play

Two targets are in play, one for replacing existing electricity supplies, the other for replacing all fossil fuel usage. A third higher target is emerging and should be included in scenarios. It provides for a surplus of clean energy for creating a clean energy export industry as described in Professor Ross Garnaut's book Superpower.

A relevant plan from conservation organisation WWF-Australia, Making Australia a Renewable Export Powerhouse (2020), quantifies three such stages of renewables growth. It is a convenient model for testing goals against the current state of play.

WWF goals are: