What is IESS, and why is it relevant to ez2view

We’ve previously mentioned IESS on this ez2view timeline site on several occasions:

1)  firstly on 9th January 2024 with ‘Preparing ez2view for IESS (IRP and BDU), which goes live Monday 3rd June 2024’,

2)  then in this ‘Progress report, in upgrading ez2view for IESS’ on 3rd April 2024,

3)  and then in Dan’s article from 17th April, which is being superseded today with this more detailed explanation of enhancements to the ‘Trends Engine’ within ez2view.

It’s become clearer that we should have started with an article something like this, which provides some starting context to the looming IESS Market Changes* before going into detail about what it means for different facets of ez2view.

*   the bulk of which are scheduled to go live in the market from Monday 3rd June 2024.


Background to IESS

Back on 2nd December 2021, the AEMC made a Final Rule for the Integrating Energy Storage Systems into the NEM.

(a)  you can find more detail about the AEMC processes on the AEMC website at their rule change sub-site for ERC0280 (their project ID)

(b)  note that in May 2023 the AEMC modified this original rule … you can find more detail about the AEMC processes on the AEMC website at their rule change sub-site for ERC0351 (their project ID)

Following the Rule Change process at the AEMC, the AEMO established its own processes for the implementation of the AEMC’s rule change.

…  you can find more detail about the AEMO implementation process on their Major Programs sub-site here.

Relevant to this rule change are a few key dates, including the following:

9th August 2023 = Aggregated Dispatch Conformance went live, as an option for Registered Participants.

Wednesday 10th April 2024 = the AEMO’s EMMS Data Model v5.3 went into production (i.e. with changes that facilitate BDUs and IRPs)

Monday 3rd June 2024 = IESS goes live.

Sometime after Monday 3rd June 2024 = when we might see the first registrations of Hybrids (and particularly DC-coupled Hybrids).

On our WattClarity® market commentary site, you’ll find an expanding collection of articles pertaining to IESS collated in this ‘Market Reform’ sub-category.

… after the rule change has gone live, we will endeavour to provide some updates as to the level of market participation this has stimulated, and the results.  Where time permits, these new articles will be aggregated in that category, so you might like to subscribe there, if not already.


Where this is relevant to Market Participants using ez2view

Our ez2view product serves the needs of a range of stakeholders in the NEM – who all have something in common, in that our ez2view-using clients all have significant (e.g. financial) exposure to what happens in the wholesale NEM.

This cohort includes:

  • Organisations such as:
    • Generators, particularly those with exposure to assets that suffer from transmission congestion,
    • Financial traders, particularly those who want to understand the details of what happens in the physical market,
    • Network companies, and
    • Some large energy users, who augment the visibility they gain from our other products with the more detailed view provided by ez2view.
  • Within these organisations we deal with two types of people:
    • Type A = There are those individuals very familiar with, and able to query directly, their own* EMMS database;
      • worth noting (re *) that for some clients we also provide assistance in establishing and maintaining the clients Hosted EMMS.
    • Type B = But there are also individuals who:
      • Don’t have so much familiarity with the EMMS
      • And don’t have the time and/or capability to write their own SQL Queries

It’s for clients in the ‘Type B’ category that we’ve built the ‘Trends Engine’ component within ez2view.


IESS increases Market Complexity

Unfortunately (in our view) some specifics of the IESS Rule Change (and implementation of it) makes the market more complex for analysts who are seeking to directly run their own queries in the AEMO EMMS database.  This complexity increases the risk that an analyst might make analytical errors in their queries, unless very thoughtful about all the corner cases the IESS changes impose.

This complexity is something we’re seeking to reduce/remove for our clients using the ‘Trends Engine’ … indeed is a stimulus to prompt us to try to declutter/simplify ‘Trends Engine’ as noted here (i.e. beyond just IESS-related market changes).


Three different types of Facilities (i.e. collections of DUIDs)

As at April 2024, our understanding of how this rule change will be implemented is that there will effectively be several different types of units.  In this note we specifically highlight three types of facilities (though there are others):

Facility Type #1 = batteries

As part of this Rule Change, it is expected* that all batteries will migrate:

1)   from having two DUIDs to represent a unit (i.e. one DUID-G1 unit to represent injections to the grid and one DUID-L1 to represent withdrawals from the grid).
2)  to having just a single DUID-NEW, which

* though there’s some uncertainty about this (for instance, about when these transitions will occur) … so we will be watching what unfolds for all existing batteries in the NEM, and any that are registered after this change.

Indeed, from constraint equations we see at April 2024, we suspect the transition will be as follows:

A key point here is that trending battery discharges over time (including ‘before IESS’ and ‘after IESS’ dates) will require selecting two different DUIDs.

Facility Type #2 = other storage units, like pumped storage hydro

However as part of this Rule Change, it is expected* that pre-existing pumped storage hydro stations (and new ones like Kidston) will continue registering as two separate DUIDs (i.e. in the same way as battery units have … up until IESS).

Facility Type #3 = hybrid units

It is likely that it won’t be some time until after the ‘go live date’ (i.e. after 3rd June 2024) that we see the first hybrid units registered into the NEM.  The rules seem to prescribe several different options by which this might be effected:

1)   In some cases (like perhaps with the already-registered complex sites at places like Bulgana and Kennedy) there may not be any substantial changes, other than the BESS at those sites becoming BDUs.

2)  But in other cases there might be some significant differences (with one being that it may not be possible to accurately identify a ‘fuel type’ for an export from a hybrid site.

… so suffice to say we will be watching these developments closely.


Number sign on Discharging/Charging becomes more confusing

Coupled with the above, the changes implemented by the AEMO will now mean that the number sign (i.e. when a data point is positive or negative in the EMMS) will mean different things depending on the data point one is looking at.

without the changes we’ve made in ‘Trends Engine’ in April 2024 (and are also making throughout the other widgets in ez2view), this would mean that one unit’s Target might be positive if charging/consuming, whereas another unit’s Target would be negative if charging/consuming … with increasing complexity coming with respect to specific configuration of units.

So within ez2view we’re attempting to make comparisons simpler, including longitudinally (e.g. if trending data back to times back before IESS went live) such that all data operates by a simple rule:

Positive numbers = represent injections onto the grid (i.e. discharge from a battery, generation from hydro, coal, gas, wind, solar, etc…).

… remembering Tripwire #3 (introduced with WDRM), this will continue to mean that dispatch of Negawatts will be seen as a positive number (i.e. a supply-side quantity, even if intangible).

Negative numbers = represent withdrawals from the grid (i.e. charging a battery, pumping uphill to a pumped storage reservoir, and consumption by other Scheduled Loads).