Wind curtailment falls to one per cent in South Australia

Curtailment of wind generation in South Australia has fallen dramatically over the first quarter of 2019, driven by changes to operating guidelines and increased availability of synchronous generation on the grid.

The Australian Energy Market Operator, in its latest Quarterly Energy Dynamics report said that the level of curtailment in the state had been reduced to around 1 per cent of the unconstrained intermittent generation forecast (fig 35).

This is a quite a change from record levels of reached in November 2018, when the market operator put curtailment at 76GWh, or about 10 per cent of the state’s non-synchronous generation.

In its report released on Tuesday, AEMO said the reduction in curtailment over the first few months of 2019 was driven by increased availability of wind and solar generation in the region, comparatively fewer periods of high wind conditions, and changes to operating guidance.

Those changed allowed dynamic levels of non-synchronous generation – ranging from 1,000MW to 1,460MW – based on the synchronous unit combinations available.

This compares to the strict rules of the previous quarter, that limited total wind and large scale solar output to 1295MW at any one time if there are not enough gas generators available to protect what it calls system strength.

AEMO said that the level of directions for system security in South Australia had also declined in Q1 2019, relative to prior quarters, with directions in place for 4.4 per cent of the time, compared to 13 per cent during Q4 2018 (Figure 34).

“This represents the least time directing (for a quarter) since the South Australian system strength arrangements were introduced,” the report notes.

This reduction in the level of directions had the happy result of also reducing direction costs, down from around $3.2 million in Q4 2018 to about $1.3 million for the quarter.

AEMO said the reduced time directing was a function of more wind and solar generator availability, influenced by periods of high demand (typical of summer) and expectations of comparatively higher spot prices.