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Author: Tristan Edis
Date: 12 July, 2013

With the 2012-13 financial year coming to a close it seemed worthwhile checking in to see how South Australia had gone with all that wind in its electricity system. Not only that, but the croweaters are also unusually keen on those silicon contraptions that generate electricity from sunlight. They install solar PV at rates per household around twice that of the Australian average.

Overall for the 2012-13 financial year South Australia reached nearly 29 per cent renewables based on data from the Australian Energy Market Operator and the NEM Review analytical tool. Once Snowtown II is completed the state should break 30 per cent.

That means the state has gone from about zero to 30 per cent renewables in less than 15 years. 

Given this achievement is within sight we thought it was worth marking with some charts of the week.

The chart below tracks the market share of each major electricity source in the state since 2005-06. The green bar illustrates the steady rise of wind, which now supplies a quarter of the state’s electricity. And in 2012-13 solar PV in light blue appears as a material player with 3.5 per cent share.

Contrary to what had been expected back in 2003, coal has been the unambiguous loser out of the rise of wind and solar PV. It was thought that gas, with its higher operating costs, would be the first to be displaced by bottom of the merit-order renewables, but for some reason that hasn’t happened.

South Australian electricity generation market share by fuel

South Australian electricity generation market share by fuel

Source: NEM Review, AEMO (2012) and AEMO (2013)

Many people said this wasn’t possible, saying renewables were far too variable to be accommodated while maintaining reliable supply. But they’re eating their words now.

In fact Alan Moran of the Institute of Public Affairs lamented at the Alan Jones Anti-Wind Rally Flop, that wind, with its extremely low operating costs, was pushing out coal. Of course he says it’s because wind is a “must run” source of power, but this is rubbish. There is no technical reason why you can’t curtail the electrical output of wind turbines, but why would you when the effective marginal cost of generating power is close to zero. 

Delving down from annual levels into five minute increments from a few days ago, the chart below illustrates just how much wind has been integrated into the SA system at individual points in time. It shows that wind has reached levels where it represents as much as 90 per cent of SA’s power demands. 

Now this has led to points where total SA power generation exceeds total SA demand (the sum of all generating sources is greater than 100 per cent). This doesn’t mean power has disappeared or been spilled (although this can happen very rarely), rather during these periods power was exported to Victoria.  This probably ended up displacing black coal generation in NSW, as Victorian brown coal generation operating costs are lower than NSW’s.  Gas has continued to play an important role in SA and its flexibility has been a good complement to wind. But coal generation tends to stay steady as inflexible baseload.

Read the article at the Business Spectator