Wind power nice in theory, better in practice

Back in March Climate Spectator explained how the large proportion of wind in South Australia's electricity supply has been pushing out fossil fuel power generation and reducing CO2 emissions. But it seems the crazies and the lazy are still out there arguing that wind power doesn't really reduce emissions; that it's all just a theory based on highfalutin modelling.

So I thought it was worthwhile revisiting, with new, real-world data based on meters not models, how wind is pushing out fossil fuels.

Back in March I presented this chart below showing the sources of power generation in SA on March 23. It shows wind (in dark blue) largely dominating with gas sitting between 35% and 50% of demand and coal at a touch above 10%.

Power fuel sources' proportion of South Australian electricity demand – 23 March 2012

Source: AEMO data provided by Infigen Energy

Now fast forward to September 5 last week. Wind battled it out with gas to meet South Australia's electricity needs. It also contributed to Victoria's needs at several times (the percentage share of wind and gas together exceeds 100% at times). And poor old coal is that purple line running along the bottom at 0%.

Power fuel sources' proportion of South Australian electricity demand – 5 September 2012

 Source: AEMO data provided by Infigen Energy

Expanding out beyond a single day, using data from 2005 up to June 2012, we can see wind has grown at the expense of gas and coal generators in SA, and to some extent the interconnector with Victoria (primarily brown coal generation).

South Australian sources of electricity supply by fuel and year

Source: AEMO (2012) South Australian historical market information 2012

And if you extended the chart back further in time you'd see that SA, largely thanks to wind, has transformed itself from almost entirely being an importer of power from Victoria, to also being an exporter during high wind periods. This change in the flows on the interconnector is illustrated below back to 1999/2000, with orange being imports from Victoria and yellow being power exports from SA into Victoria.

Total SA-VIC interconnector flows

Source: AEMO (2012) South Australian historical market information 2012

And naturally CO2 emissions associated with SA's electricity supply have declined as illustrated below.

Annual CO₂ emissions from South Australian power supply

Source: AEMO (2012) South Australian historical market information 2012

Now if some retired engineer claims that wind is not reducing emissions because the coal generators are burning coal in the background, can they please explain how this is possible when the two coal generators in SA have just been taken out of operation?

O and by the way the lights have not gone out.