On this page we’ve provided some basic details of the data points delivered in the RenewEconomy widget.
On this page we’ll delve into more details….
(A) The Unit of Measure is “megawatts”, which is a Rate
As noted in the FAQs here, all data is shown in megawatts (i.e. MW) … with 1MW = 1,000kW = 1,000,000 W.
Remember that a rate of energy generation/transfer/consumption is measured in MW whereas a volume of energy generation/transfer/consumption is measured in MWh (i.e. a rate over a period of time).
On 24th April 2018 we published this lengthy ‘explainer about electricity demand’ that includes the following animated image that helps to explain this visually:
What is included in the RenewEconomy widget are instantaneous MW … so they are rates of Supply and Demand (not volumes).
(B) A “point in time” view
The widget shows data aggregated together from several different data providers – so the data points shown in the widget are of slightly different cadence, and timestamps.
1) We have designed the widget to show the most current data available
2) You can mouse-over a particular data point to understand more.
If you’d like to trend data over time, you might find our NEMreview product to be of use in that respect – all of the data sets in the widget (and 10,000’s more) are available for licensed users.
(C) About the main grids
It should be noted that the widget does not provide visibility of all of the electricity supplied across the country – however it does provide visibility of the lion’s share. This is the case because the NEMwatch widget shows the supply and demand balance across Australia’s two main electricity grids:
1) In the east, Australia’s National Electricity Market (NEM) covers only ½ of the Australian land-mass but accounts for roughly 90% of electricity consumed across the country.
2) The second major grid is the South-West Interconnected System (SWIS) that supports Wholesale Electricity Market (WEM) which supplies the cities of Perth and Fremantle, and surrounding areas of south-western WA.
3) See the FAQs for information about the other (missing) grids … and why ACT is not directly visible.
(C1) The SWIS, in Western Australia
In the widget we show data from the SWIS as representing the whole of Western Australia – which is not strictly correct, but which is an approximation that is of a reasonable level of accuracy (i.e. given the total electricity consumption in other parts of Western Australia (including in the missing grids below) is relatively low).
The WEM operates in local Perth time, which is UTC + 8 hours. This means that clocks in the WEM are 2 hours behind “NEM time” clocks – however all data in the widget (e.g. when you mouse over) is translated to NEM time to reduce confusion (though we know this will not totally alleviate all confusion, unfortunately).
With respect to the data shown as Supply-and-Demand for the whole of Western Australia (but in most cases representing just the SWIS), please note the following:
Supply-side Data
in Western Australia |
In response to questions we’ve fielded on this widget since it was first launched in early 2015, we’ve provided some details below about the sources of the data used to represent Western Australia.
| Black Coal, Gas, Liquid, Wind, Large Solar |
Data for these fuel types is supplied by the AEMO West (formerly the IMO) and is of a 30-minute cadence.
A focus of the widget is providing a high-level picture, so rather than distracting with unit-level data (which is available as a time-series in NEMreview v7) in the widget we take the raw data published by AEMO West, and aggregate up to fuel type using mapping functions we have established in our Asset Catalog.
|
| Other |
The primary objective of the widget is to assist in raising the general level of awareness of the big picture of the current fuel mix providing for electricity supplies across Australia. Hence on some occasions simplifications are used.
One of these simplifications has been to omit specific fuel types where they represent only a tiny proportion of the electricity generated across Australia in order to ensure the widget is as clear, and least crowded, as possible. In cases such as this, generation from these other fuel types are aggregated together under an “Other” category.
Our Asset Catalog is also coded such that, whenever new Generators are added, any data pertaining to these new units are aggregated under the “Other” category until such time that the new units have been correctly assigned to their proper fuel type. Hence keen observers might observe some short periods after new stations begin operation when the “Other” category jumps for an interim period.. |
| Small Solar |
In March 2015, this widget was updated to include “APVI Small Solar”. This is the estimated production from small-scale (i.e. predominantly rooftop) solar PV derived by the Australian PV Institute (APVI).
The method used by the APVI has been progressively evolved, over time, with the objective being to improve the accuracy of the estimate – however the key points to understand are that:
1) This particular data set is an estimate, as distinct from actual metered data for the larger-scale plant;
2) At its root, the estimation method is a “sample and extrapolation” method, whereby real output for a sample number of smaller installs is then extrapolated up to an estimated aggregate based on the total installed capacity of small-scale solar in a particular location. It’s not perfect but (currently) is the best available method. The challenges of the estimation method were also discussed in this Wattclarity article from June 2016.
This estimate is actually supplied for the whole of Western Australia, but we have made the assumption (because of population density) that this is almost equivalent to production in the SWIS. |
| Medium Solar |
Refer to the FAQs for what Medium Solar is, and why there is no visibility (and example of Villain #8). |
| (Large) Battery Discharging |
There are no large-scale battery facilities currently operating in the SWIS. See below for the regions of the NEM. |
| (Small) Battery Discharging |
There currently are already a number of small-sized battery systems operation in the SWIS (and more broadly across WA).
However currently there is no visibility about how many battery systems are currently installed, and of what type – let alone any visibility of how these are operating. This presents a number of growing challenges for the grid in this multi-faceted energy transition, and was the reason why we started our process of developing a national Energy Storage Register.
In the absence of data such as that, we cannot provide any visibility in this widget of when these smaller systems are discharging (i.e. acting like generators). |
| Other missing data |
We’re missing other embedded generation, for instance. |
If this does not answer the questions you had about Supply-Side Data for WA, please provide your feedback here. |
Demand-side Data
in Western Australia |
In this widget, we start with the principle that (because the SWIS is an isolated grid) instantaneous supply must always equals instantaneous demand.
| Demand (approx AEMO Operational) |
Given that starting point, we have taken the approach of setting the “Operational Demand” number for Western Australia to be the simple sum of all of the generation supplied in the region at that same point in time – with the exception of the Small-Scale Solar (which is needed to be represented as below). |
| Demand (Pumping Hydro) |
There are no pumped storage hydro facilities currently operating in the SWIS. See below for the regions of the NEM. |
| Demand (Large Battery Charging) |
There are no large-scale battery facilities currently operating in the SWIS. See below for the regions of the NEM. |
| Demand (Small Battery Charging) |
As noted above, there currently are already a number of small-sized battery systems operation in the SWIS (and more broadly across WA).
However in the absence of visibility of these battery systems (which we’re seeking to address with a national Energy Storage Register) we cannot provide visibility in this widget of when these smaller systems are charging (i.e. acting like loads). |
| Demand (the AEMO doesn’t see) |
We treat the APVI small-scale solar production data for WA the same as we do for each of the regions of the NEM on the demand side, labelling it “Demand the AEMO doesn’t see” in real time. |
If this does not answer the questions you had about Demand-Side Data for WA, please provide your feedback here. |
We’ll refine the above description of the data used to represent WA based on your feedback you can provide here.
(C2) The National Electricity Market (NEM) on the east
In the widget we show data for each of the states that combine together to comprise the NEM (noting that there are pockets of some states not connected up to the NEM and hence overlooked in the data sets provided in the widget).
The NEM operates in Eastern Standard Time, which is UTC + 10 hours and does not adjust to daylight savings in NSW, VIC and TAS (nor does it adjust to the time-zone difference to South Australia). People who work in the wholesale market are familiar in thinking in “NEM time” (but we appreciate that this concept will be foreign to some of the broader range of users of this widget).
With respect to the data shown as Supply-and-Demand for the NEM regions (Queensland, New South Wales, Victoria, Tasmania and South Australia), please note the following:
Supply-side Data
in QLD, NSW, VIC, SA, TAS(see the FAQ about why there’s no ACT shown) |
In response to questions we’ve fielded on this widget since it was first launched in early 2015, we’ve provided some details below about the sources of the data used to represent the NEM.
| Black Coal, Brown Coal, Gas, Liquid, Wind, Large Solar |
Data for these fuel types is supplied by the AEMO East (formerly NEMMCO) and is of a 5-minute cadence.
It is metered data at an “as generated” level (so not equivalent to the “sent-out” level used later for settlement), sampled from SCADA just prior to the start of a (5-minute) Dispatch Interval, but shown at the time point for the end of the Dispatch Interval – i.e. offset by a little over 5 minutes from the time at which it was actually metered.
A focus of the widget is providing a high-level picture, so rather than distracting with unit-level data (which is available as a time-series in NEMreview v7 or in real-time in ez2view) in the widget we take the raw data published by AEMO East, and aggregate up to fuel type using mapping functions we have established in our Asset Catalog. |
| Hydro Production |
This number (a single number for each region) shows the aggregate of each of the hydro production across a particular region – regardless of the type of hydro facility.
It is not possible to separately identify (in pumped storage hydro) if the water molecules had been previously pumped uphill, or had accumulated in the upper pond due to rainfall (or snowfall). |
| Other |
The primary objective of the widget is to assist in raising the general level of awareness of the big picture of the current fuel mix providing for electricity supplies across Australia. Hence on some occasions simplifications are used.
One of these simplifications has been to omit specific fuel types where they represent only a tiny proportion of the electricity generated across Australia in order to ensure the widget is as clear, and least crowded, as possible. In cases such as this, generation from these other fuel types are aggregated together under an “Other” category.
An example here is for the three sugar mills in QLD that have data accessible to, and published by, the AEMO in real time – Invicta, Pioneer and Rocky Point. There are a number of other sugar mills (each with power stations, though smaller still), but these have not data accessible to AEMO in real time.
Our Asset Catalog is also coded such that, whenever new Generators are added, any data pertaining to these new units are aggregated under the “Other” category until such time that the new units have been correctly assigned to their proper fuel type. Hence keen observers might observe some short periods after new stations begin operation when the “Other” category jumps for an interim period.. |
| Small Solar |
In March 2015, this widget was updated to include “APVI Small Solar”. This is the estimated production from small-scale (i.e. predominantly rooftop) solar PV derived by the Australian PV Institute (APVI).
The method used by the APVI has been progressively evolved, over time, with the objective being to improve the accuracy of the estimate – however the key points to understand are that:
1) This particular data set is an estimate, as distinct from actual metered data for the larger-scale plant;
2) At its root, the estimation method is a “sample and extrapolation” method, whereby real output for a sample number of smaller installs is then extrapolated up to an estimated aggregate based on the total installed capacity of small-scale solar in a particular location.
It’s not perfect but (currently) is the best available method – see the FAQs for more discussion. |
| Medium Solar |
Given that the small-scale solar figure relies on an installed capacity derived from STC registrations at the Clean Energy Regulator, and that there are a growing number of solar installations across Australia qualifying for LGCs instead (i.e. being larger than 100kW), but not being big enough to warrant the AEMO accessing live production from SCADA systems, there will be a growing volume of “Medium Solar” production not accounted for in the Small Solar or Large Solar numbers.
Refer to the FAQs for what Medium Solar is, and why there is no visibility (and example of Villain #8). |
| (Large) Battery Discharging |
As noted on Wattclarity in November 2017, the Telsa/Neoen battery in South Australia named the “Hornsdale Power Reserve” began charging on Saturday 25th November. Discharge was also shown on the same day.
Other large batteries will follow in relatively short time, and will be visualised in the widget.
When discharging (like is the case for hydro), these batteries need to be accounted for by the AEMO in the scheduling process. Hence the AEMO accesses, and publishes, metered rate of production for these batteries. In our widget we aggregate these by region to highlight operational pattern. |
| (Small) Battery Discharging |
There currently are already a number of small-sized battery systems operation across each of the NEM regions.
However currently there is no visibility about how many battery systems are currently installed, and of what type – let alone any visibility of how these are operating. This presents a number of growing challenges for the grid in this multi-faceted energy transition, and was the reason why we started our process of developing a national Energy Storage Register.
In the absence of data such as that, we cannot provide any visibility in this widget of when these smaller systems are discharging (i.e. acting like generators). |
| Other missing data |
We’re missing other embedded generation, for instance. |
If this does not answer the questions you had about Supply-Side Data for any of the NEM regions, please provide your feedback here. |
Demand-side Data
in QLD, NSW, VIC, SA, TAS(see the FAQ about why there’s no ACT shown) |
In this widget, we start with the principle that (across the NEM as a whole) instantaneous supply must always equals instantaneous demand.
| Demand (approx AEMO Operational) |
In the real-time operation of the NEM, it is not possible for the AEMO to aggregate a live reading of all of the millions of consumption meters scattered across the NEM. Hence, in order to “measure” demand in real time, the AEMO adds up all of the electricity supplied by the generators it can see and makes adjustment based on interconnector flows to derive a region-level demand number.
In the widget, given that we want to explicitly show pumping at pumped storage hydro facilities, we are unable to use any of the AEMO’s own aggregated demand figures (there are a few).
Instead, we have to adopt our own approach by:
#1) Add up supplies for all generators in the region;
#2) Add onto this any imports from neighbouring region (as they are supplying consumption in the region in question); whilst
#3) Subtract off exports to neighbouring region (for the same reason).
This gives us our estimate for what the AEMO refers to as “Operational Demand”.
A little later on we will link through to an even greater description of Operational Demand. |
| Demand (Pumping Hydro) |
In the NEM there are currently 3 pumped storage hydro facilities:
#1) the upper reservoir at Tumut in the Snowy Scheme
#2) the Wivenhoe pumped storage system in South-East Queensland, where the hydro reservoir sits above the large Wivenhoe flood mitigation and water supply dam; and
#3) The Shoalhaven scheme in NSW.The pumping loads associated with each of these schemes are Scheduled Loads, meaning that the owners of these facilities bid into the NEM for prices below which they will be happy to consume (i.e. pump water uphill to charge their “battery”).Because of this, the AEMO accesses, and publishes in real time, metered data for the current rate of consumption at each of these facilities. These charging rates are aggregated up for the relevant region, and shown in the widget.
Note that these demands are integrated into the AEMO’s “Demand and Non-Sched Generation” data set, which is why we can’t use that directly in the widget and hence have to compile our own estimate of Operational Demand. |
| Demand (Large Battery Charging) |
As noted on Wattclarity in November 2017, the Telsa/Neoen battery in South Australia named the “Hornsdale Power Reserve” began charging on Saturday 25th November.
Like the pumping loads in pumped hydro, the “pumping” load used to charge the battery is also a Scheduled Load. Hence the AEMO accesses, and publishes, metered rate of consumption for these batteries. In our widget we aggregate these by region to highlight operational pattern. |
| Demand (Small Battery Charging) |
As noted above, there currently are already a number of small-sized battery systems operation in each region of the NEM.
However in the absence of visibility of these battery systems (which we’re seeking to address with a national Energy Storage Register) we cannot provide visibility in this widget of when these smaller systems are charging (i.e. acting like loads). |
| Demand (the AEMO doesn’t see) |
Because of the approach the AEMO takes to calculating a real-time view of Operational Demand, they effectively do not (cannot currently) “see” the share of consumption that small-scale solar production is supplying.
It’s irrelevant, from the perspective of this widget, whether an individual’s small-scale solar is exported to the grid, or consumed at home (though we’ve noted here on WattClarity how the incentives vary for each owner of a system).
The key point, from the perspective of this widget is that the AEMO does not see, in real time, the share of consumption supplied by small-scale PV. Hence it is listed as such on the widget.
Refer to the FAQs for more discussion.
|
If this does not answer the questions you had about Demand-Side Data for any of the NEM regions, please provide your feedback here. |
We’ll refine the above description of the data used to represent each region of the NEM based on your feedback you can provide here.
(C3) Notable grids (and areas) not currently covered by the NEMwatch Widget
Refer to the FAQs for further discussion.
If you can help us gain access to data for any of the above, please let us know how (by using this feedback form)
