VWA Prices are synonymous to LWA Prices.
First thing to understand is that Volume-Weighted Average Prices (VWA Prices) are not quite the same as Volume-Weighted Average Revenues (VWA Revenues). VWA Prices is a metric that is not as commonly used as VWA Revenues, but can be quite useful as described below.
(A) Calculating VWA Prices
The VWA Price is determined over a period of time is the ratio of Spot Revenue for Energy for a generator (or a group of generators) as if it were at the Regional Reference Node, divided by the Production (typically ‘As Generated’, though this might vary – so be wary) over the same period.
VWA Price = Hypothetical RRN Spot Revenue (Date1 to Date 2) / Production (Date1 to Date2).
… where in the NEM the ‘Hypothetical RRN Spot Revenue’ is calculated:
Spot Revenue = Sum, for every Trading Period (Production Sent-Out (i.e. MWh) x MLF (assumed to be 1.0) x Trading Price in Region (i.e. $/MWh))
(B) Usefulness of VWA Prices
The VWA Price is a good metric to use if you want to compare between different assets and clearly understand their historical performance in harvesting times of high spot prices, and avoiding instances of negative spot prices.
It’s better than the VWA Revenue at providing for this because it does not take into account the MLF (i.e. results are not masked by other locational issues).
We first used the VWA Price in the Generator Statistical Digest 2019.
On the ‘B Pages’ for every DUID that was operational in 2019 we included an annual figure for VWA Price for each DUID, and also broke this down into monthly averages through CAL 2019. Upon release of the GSD2019 on 28th January 2020:
1) Guest author, Allan O’Neil, utilised the VWA Prices and other data in the digest to explore ‘How good is Solar Farming?” (see discussion of ‘Headwind 2 – Spot Discount’; and
2) Guest author, Ben Willacy, also touched on VWA Prices in his article about ‘What lies ahead for the NEM in 2020? Some lessons from 2019’.
Some other articles referencing ‘VWA Prices’ can be found under this tag (where we have remembered to do so).