Changes to the Trends Engine in preparation for IESS

This article has been superseded (and expanded) with these two later Release Notes:


As many of our clients may be aware, our development team is currently preparing our software products to be compatible with upcoming Integrating Energy Storage Systems (IESS) market rule changes to be incorporated in v5.3 of the AEMO’s MMS. Paul last provided an update on this progress on the 9th of April 2024, which included a timeline of key dates with respect to the rule changes. Prior to this, Paul posted a short note on January 9th 2024 which contained an outline of how the IESS rule change will impact ez2view.

In this short release note, we would like to highlight specific changes that we have begun to implement in the Trend Engine within ez2view. These changes specifically relate to the labelling and interpretation of data series and the data selection interface itself.

We have moved the existing Generators tab, and marked it as ‘legacy’

Some of our users may have seen the message below appear in their copy of ez2view whilst using the trend editor in recent times:

As described in this note, our new distinction between ‘power’ and ‘energy’ necessitates us to slowly transition users away from the existing paradigm for how users select unit-level data. As an interim step in this process, we have moved the existing Generators tab to the end of the menu bar and labelled it as ‘legacy’.


Users who have existing trends with certain data series within the Generators tab will need to be aware that the calculations/definitions of some of these data series have changed.

We have renamed ‘Energy Generated’ to now be labelled ‘Energy Generated (Estimate)’ to better reflect that this is an estimated value. But more importantly, since this ‘Generators’ tab includes all units (and since consuming units do not “generate” energy), we have altered the series to be zero for any unit that is consuming – this mostly affects loads but also bi-directional units in the future.

Similarly, in this tab the InitialMW data series has been named ‘Initial MW (Generation)’  and the FinalMW series has been renamed ‘Final MW (Generation)’. We are altering the definition of these series to be representative of units that are generating. Previously, this series had positive values for both loads and generators which when aggregated could produce potentially misleading results.

Consistent with this we have created a new series ‘Initial MW (Load)’ which provides for backwards compatibility to allow the aggregation of consuming units. Therefore, this value will be zero for generators but will still present positive values, representative of the load-side / consumption.

We’ve created a new Units tab, which makes the distinction between ‘power’ and ‘energy’

In a new move, we have created a new ‘Units’ tab in the menu bar which we plan to eventually replace the Generators (Legacy) tab.

To make the distinction between rates and volumes of electricity clearer we have now:

  1. Created a new data series ‘Power (MW)’ which essentially is a replacement for the ‘InitialMW’ series detailed above , but
  2. Changed the logic so that this new series will show a positive value for generation, and show a negative value for consumption.

Therefore, for those units that will be registered as a ‘Bi-Directional Unit’ (BDU), these values will be positive when generating and negative when charging.  Similarly, the equivalent of our historical ‘Energy Generated’ data series (i.e. megawatt hours), has now been labelled as ‘Energy (MWh)’ in the new tab and will similarly show positive values for generation and negative values for consumption. Scheduled loads will also show generally show negative values.

We’ve added a new Group By category, named ‘Type’

In the new ‘Units (NEM)’ tab we have amalgamated AEMO’s ‘Fuel Type’ and ‘Load Type’ as previously appeared in the now legacy Generators tab. As shown in the screenshot above, there are currently eight values within this new category. We have implemented this new category in order to make it simpler for users to select aggregations of units, especially for storage units. Please note that the new ‘Units (NEM)’ tab only includes units registered for the Energy Market. In a future release, we will introduce another new tab focused on the selection of Units registered for FCAS.