% VRE and % Renewables in the ‘Live Supply & Demand’ widget

We (at Global-Roam Pty Ltd) added in these four percentages in November 2022 to assist users of the widget (at RenewEconomy and elsewhere) keep track of the current status of energy transition.

Background to the Upgrade

There are two sets of two percentages – one set for the NEM (which is where our focus is), and one set for the WEM (which operates in the south-west corner of Western Australia).

% VRE (i.e. Variable Renewable Energy)

Whilst the ratios might seem similar in purpose, for us the % VRE (Variable Renewable Energy) is much more important, as it speaks to some of the underlying challenges that will need to be worked through in the energy transition – because wind and solar:

    1. Is intermittent
    2. Is not synchronous
    3. Is not dispatchable (i.e. Wind and Large Solar is registered as Semi-Scheduled in the NEM, and rooftop PV is even less controllable – and indeed is invisible in real time)

% Renewable

The % Renewable metric adds in the contribution from hydro in the NEM (there’s no hydro in the WEM) … but hydro is quite different than Wind and Solar because:

    1. it’s not intermittent,
    2. its synchronous,
    3. it’s fully dispatchable (e.g. registered as fully Scheduled)

Because of this, the % Renewable metric is less useful from a practical point of view about technical decision making about the ongoing energy transition (and more easily confused).

It’s more used by people more focused on policy settings.

 

Specific definitions

In the table below we explain the specific formulas:

Table Element: What does it mean?
% VRE

Variable Renewable Energy (VRE) is the name commonly given to supply of electricity from wind and/or solar.

In terms of the various fuel sources shown in this widget, this means the aggregate supply from:

1)   Wind:

(a)  as metered in the NEM by the AEMO on a 5-minute basis

(a)  as metered in the WEM by the AEMO

2)  Large Solar:

(a)  as metered in the NEM by the AEMO on a 5-minute basis

(a)  as metered in the WEM by the AEMO

3)  Small Solar, which is:

(a)  As at November 2022, estimated by AEMO in the NEM on a 30-minute cadence, somewhat lagged from the rest of the data set.

(b)  As at November 2022, estimated by APVI in the WEM on a 30-minute cadence, somewhat lagged from the rest of the data set.

… you might recall these prior notes about the ‘Ongoing opacity of rooftop PV’.

% VRE = [ VRE / total supply ]*100.
Renewables (%)

% Renewable = [ Renewables / total supply ]*100.

 

 

More details about the widget

On this introductory page, we provide further details about this widget.

 

Answers to your ‘Frequently Asked Questions’

Don’t forget that we’ve already tried to answer many of the Frequently Asked Questions we receive for the widget.