Clean energy: the state of play

CO₂ emissionsfall as fossil fuel usage in electricity generation declines. That's the main aim of replacing fossil fuels with renewables.

Table 2. A decade of fossil fuel consumption in Australia's electricity supply sector, PJ

Data from Department of Industry, Science, Energy and Resources, Australian Energy Statistics

Table F, Section 26 Electricity supply, Fuels consumed (September 2020)

Table 2 shows coal use dropping, especially higher-emission brown coal, where mine and plant closures were widely reported. On the other hand natural gas and liquid fuel usage rose. Total fossil fuel use (last row) showed a small irregular downward trend of around 1% per annum. Over 10 years renewables grew from 78.5 PJ to 187.3 PJ, i.e. 239%.

Why does the drop in fossil fuel consumption, 10% over 10 years, not reflect renewables growth? Solar and wind intermittency is the likely explanation. When generation drops the slack is taken up by fast-starting open-cycle gas turbines and/or diesel generators. Contrary to widespread opinion, batteries do not have that role though they do play a specialised part in the national grid, providing so-called Frequency Control Ancillary Services. There are plans to increase pumped hydro storage, which is suited to grid scale. But as things stand backup still relies largely on fossil fuels.

Fossil fuels – power stations vs the rest

The breakdown of total fossil fuel consumption for electricity generation (thermal electricity) can tell a lot about future reduction of emissions. Table 3 gives the data for financial year 2018-19, the latest full year available.

Table 3. Fossil fuels in Australia's electricity supply sector 2018-19, PJ

(Same source as Table 2)