Case Study of Tuesday 23rd August 2022 (Part 1) … large instance of collective over-performance for Semi-Scheduled units

This weekend we’ve been completing analysis for GenInsights Quarterly Updates for Q1 2023 – and in particular (at present) focusing on Semi-Scheduled units, and instances of large collective Aggregate Raw Off-Target in either direction.

In doing this we’ve flagged two days during Q1 2023 that say large deviations:

1)  On Friday 20th January 2023 we saw several large deviations of collective over-performance; and

2)  On Friday 3rd February 2023 we saw two sequential deviations of collective under-performance (in megawatt terms, larger than the above).

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Given we’re posting about events like these, I thought it would also be useful to post this quick overview of Tuesday 23rd August 2022 (which was initially flagged in GenInsights Quarterly Update for Q3 2022) which saw a large collective over-performance at 13:15 on the day:

As noted on the chart, the largest collective over-performance was AggROT = -650MW at 13:15.

What’s not noted on this chart was that this incident was second-largest ever incidence of collective over-performance at this point in time.