Clean energy: the state of play

There is a buoyant mood within the renewables industry, its supporters, and various governments and agencies, typified by expansive claims, self-congratulation, bold plans and extravagant headlines. The habit of quoting growth in terms of added capacity (maximum power output) rather than energy magnifies impressions of growth since output of intermittent renewables varies between zero and nameplate capacity.

Evocative marketing descriptions like "renewable energy powerhouse" are common even in official government announcements. "Australia strengthened its position as a renewable energy powerhouse in 2020" says aFebruary 2021 press release from the Federal energy minister's office.

The excited mood tends to overshadow sober analysis. I'm reminded of the "irrational exuberance" of the dot-com boom. It encourages wishful thinking and presents a risk to sound policy development. Hence the present analysis, which relies on official statistics and energy quantities for targets and performance assessment.

Renewables growth rates and performance indicators

Table 1 summarises the recent history of Australia's electrical energy output. Units are petajoules PJ, the basis for most of Australia's energy statistics. 1 PJ = 10¹⁵ joules. For the size of Australia's energy systems (e.g. typical 1 gigawatt power stations produce about 30 PJ per annum)petajoules offers convenient numerical quantities and accessible analysis.

Table 1. Australia's electricity (PJ): the state of play

Data from Australian Energy Statistics Table O

Salient points are:

• Solar and wind were the growth sources.
• Total electricity output rose modestly (4.4%) over the period.
• Total renewables content grew from 14.1% in 2015 to 24.4% in 2020.
• Solar and wind components grew faster than total renewables. Solar rose nearly four-fold. Wind almost doubled.
• Annual growth of solar + wind energy (last row) shows signs of levelling off. This may well be temporary. The maximum growth rate to date is 33.1 PJ per annum, reached in 2019.

Growth rate as per the last row measures the true rate of approach to targets and ought to be the key performance indicator. It never gets mentioned.

Fossil fuel consumption in Australia's electricity supply