Clean energy: the state of play

A. 100% renewables, for cleaning up electricity supplies.

B. 300% renewables, for an all-electric economy.

C. 700% renewables, for yielding a clean energy surplus to supply new green energy export industries with products like "green hydrogen" produced electrolytically with clean electricity.

WWF chose 700% so as to yield green fuel exports at scale equivalent to Australia's present LNG trade.

Let's see how those targets look against 2020 solar/wind growth rates (Table 1). To keep things simple, numbers are rounded and adjustments for changes in GDP per capita, population etc. over the intervening years are ignored.

Starting parameters are: total electricity 955 PJ; existing renewables output 235 PJ; solar/wind growth constant at 31 PJ per annum. The above three WWF goals become

A. 955 PJ

B. 2865 PJ and

C. 6685 PJ.

Hence, reaching

A. 100% renewables would take 23 years

B. 300% renewables would take 85 years