Reconciling daily generation report with gentailer operating report data

  • Last post 25 May 2018
Alexanderm posted this 21 May 2018

I would like to reconcile the data in the Grid generation trends data with the generation figures published by the major gentailers to the NZX. For example, I have calculated Mercury's generation for the three months ending March 31st as 1700 GWh using the Grid Generation Trends data. According to Mercury's Quarterly Report (attached), they generated 1626 GWh in this time period.
The nodes I am using for Mercury's generation are in the comments section.


Any assistance would be greatly appreciated

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Alexanderm posted this 21 May 2018

Phil Bishop posted this 21 May 2018

My first reaction would be to say this is perhaps a question best answered by somebody from Mercury, as I am unable to explain to you how Mercury put their reports together. That said, they would know better than anybody else how much they generate.

As note #3 to our Grid generation trends report states, we use reconciliation data. More specifically, it is the so-called GR-010 report if you want to look up the reconciliation manager functional specification to see what's in the GR-010 report. I would say that what is in the GR-010 report is almost certainly not the same as what Mercury says their plant did. But whether or not the difference is 74 GWh over the three months you're looking at I couldn't say.  


Cheers, Phil


Phil Bishop posted this 25 May 2018

My colleague Matthew noted that a significant chunk of what appears to be a discrepancy might be explained by the fact that some businesses have arrangements with traders to offer in energy and/or reserves on behalf of those businesses. So what reconciliation shows as Mercury, say, might actually be Mercury acting for somebody else who doesn't want to mess around being a trader.