PEC Stage 2 enters the ST timeframe

As of today, the 24^th September, there are 7 days until the 1^st of October:  when the new NSW1-SA1 interconnector will become effective in dispatch.

That 1^st of October date is now inside the ‘ST’ (short term) time horizon.  As such, we are seeing the new NSW to SA interconnector included in ST-PASA results.

We can view ST-PASA results with ez2view:

Before discussing these results, a reminder on STPASA LOR assessments can be useful. I’ve take these points from the ST-PASA procedure:

• • Since LOR (Lack of Reserve) assessment is required for each region in the NEM, ST PASA runs a separate reserve assessment for each region.
  • The region for which the LOR reserve is assessed is taken as the study region.
  • Supply demand balance is met in other regions and the surplus/deficit supply in other regions is transferred to the study region, subjected to network constraints. Then the reserves are assessed for the study region to determine reserves and LOR conditions. Each region is taken as study region in-turn and the reserve assessment is conducted.

Overall, we can see the capacity MW flows constrained to 0 MW until about midday on the 1st. This is in line with the cutover plan. The current PASA outlook runs until 4am on the 2nd and see only see data for the new interconnector from when it becomes effective on the 1st.

Once the shackles are losened – the NS_ or SN_ZERO constraints are lifted – from about midday on the 1st, we see capacity for non-zero flows in the ST-PASA results.

In the SA LOR assessment, we see NSW1-SA1 generally being able to flow at the calculated limit of 150 MW into SA to support SA reserve levels.

In the NSW LOR assessment, we see capacity for flows in the midday not directly supporting NSW until the afternoon (16:30).  This is a reminder that we’ll be needing to consider all arms of the loop as we go forward.

For VIC, the NSW1-SA1 flows are similar to the NSW study region results.  There appears to be a tendency for capacity to supply SA to support the study region in the middle of the day and then swing back to NSW for the evening. A brief check of V-SA indicates this would have capacity to flow in the SA-to-VIC direction in those midday situations.

We look forard to analysing the results further, and to the inclusion of NSW1-SA1 in P30 predispatch results in the coming days!