Dear Electricity Authority,
Via your organisation's web site https://www.emi.ea.govt.nz/Wholesale/Dat..., half-hourly data on the generation (and consumption) of electricity at the Ngawha A and Ngawha B power stations are provided, starting with May 2021. However, the new Ngawha B power station commenced supplying power to the grid months earlier. Please supply the corresponding data series from the time that Ngawha B commenced, up to May.

Yours faithfully,
Nicky McLean

Dear Electricity Authority,
A group response was made via https://fyi.org.nz/request/19587-please-...
The relevant part is “This information is also not held by the Authority and would need to be created in order to respond to your request. The metered data published on EMI is as received from Transpower.”

Amongst the data files provided via “EMI” is the collection that is recommended in the main response, https://www.emi.ea.govt.nz/Wholesale/Dat... which as you can see is a sub-component of the EMI webpage and thus “published on EMI”. These files in turn contain data for the following names:
KOE.KOE0331.TOPE.ngawha.Geo.Geo 1/1/2009-31/3/2012
KOE.KOE1101.TOPE.ngawha.Geo.Geo 1/4/2012-31/5/2022
These series abut, and can easily be seen to be for Ngawha A. Except for a few months when Ngawha B started, it is for Ngawha A + Ngawha B combined. Then starting with May 2021 it is again for Ngawha A alone. So, after a brief presence, the generation at Ngawha B has vanished, and it is the larger of the two. This error is a consequence of not having separate data for Ngawha A and Ngawha B, as requested, and will be an ongoing source of error for the unwary until this detail is rectified by acquiring data for A and B separately and replacing the (A + B) data in the A series by (A) data..
There is no need to “create” the requested information, because the relevant data series already have been created. It is simply a matter of removing the wrong information and adding the missing information to the existing data series and thereby enable a correct accountancy without traps. If your organisation does not have the data, this would be an opportunity to enact your claimed dedication “to continuously improving the way we collect and publish data.” by finding them and removing a trap, rather than spending time re-supplying data files with negative improvements and added errors, as described against the group response noted above.

Yours faithfully,
Nicky McLean