Large instantaneous jump in ‘Market Demand’ in NSW on Tuesday afternoon 18th February 2025

We’ve written before (such as with respect to the large apparent drop on Friday 31st January 2025) about that ‘Notifications’ widget alert in ez2view looking at large changes in ‘Market Demand’ for various regions:

1)  The alert setting for NSW (with a tolerance of a 400MW change) has been set for ages;

2)  But (apart from 31st January and 7th February) I can’t recall it triggering many times before … which makes today’s second instance (at least that I remember!) noteworthy:

To accompany this and show some context, here’s a snapshot of NEMwatch for the 16:10 dispatch interval (NEM time) on Tuesday 18th February 2025:

Notable here that the jump in demand was up +504MW or up 7.6% (with correct rounding).

1)  That’s not insignificant

2)  What’s the cause:

(a)  Is it some glitch?

(b)  Is it due to some treatment of flow or losses (not sure I can see how, immediately – but it’s been a while since I checked into the detailed logic for how AEMO adds up to that number)?

(c)  Is it a byproduct of the rise and rise of rooftop PV?

… or something else?

3)  What are the implications for the future?

Note that in the same dispatch interval there were other significant changes in ‘Market Demand’:

• in South Australia up from 727MW to 829MW (i.e. up 102MW or 14%)
• in Victoria down from 4,309MW to 3,989MW (i.e. down 320 MW or 7.4%)
• So NEM-wide up from 20,006MW to 20,356MW (i.e. up 350 MW or 1.7%)