2014-12-16 was windy in South Australia. Renewables (entirely wind) provided 7.5% of the Whole Grid energy and 62% of South Australia’s electrical energy.
Unfortunately the peak of wind power 9am-7pm did not coincide with the peaks of demand at 8am and 8pm and there was 80-100% of reserve power available from other operating generators. This amount of instant reserve power seems untypically large and implies some fuel wastage.
The Regional Reference Price in South Australia dropped to almost 10 $/MWh for much of the day. While good news for electricity retailers, it may be below the survival price for other types of generators which are need on calm days
The Lake Bonney Stage 3 Wind Farm (LKBONNY3) raises some interesting questions which I don’t have time to investigate at present.
For most of the time that the state price was down near 10 $/MWh, the LKBONNY3 Local price was -50 $/MWh. Yes MINUS $50. For most of this -$50 period LKBONNY3 produced no power, which seems sensible if the Local price actually means anything. However for some of the -$50 period LKBONNY3 was running at 80% Capacity factor, which is interesting.
At about 12:40pm the state price spiked down to less than -30 $/MWh at the same time as LKBONNY3 Local price spiked down to -300 $/MWh. As LKBONNY3 was producing no power at the time of the spike, it can hardly have been a signal to produce less power. Was it a threat?