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 various places are provided, in particular for wind farms on the Tararua Range. There have been multiple developments, but this concerns the rather unusual Te Rere Hau wind farm. Its early form was small, and its generation was apparently limited by the capacity of the connection to Linton. Nevertheless, data were supplied, but, that series stops abruptly with March 2008.
In the same year, the wind farm was greatly enlarged and connected instead to the national grid, with operation beginning in September 2008 as recorded by a new data series, and working up gradually from small values, below those from the tail end of the first series.

This request is for the missing half-hourly data from the first stage of Te Rere Hau, extending from March 2008 up until its cessation, if it has ceased. That is, ceased supplying to Linton by the local connection. This could proceed even as the new grid connection becomes used for the massively larger expanded wind farm. Alternatively, the existing turbines of the original collection could have been disconnected from Linton and converted to the new grid connection. Information on this would help clarify matters.

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.”

There is no need to “create” the requested information, because the relevant data series already have been created. It is simply a matter of adding the missing information to the existing data series. 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, rather than spending time re-supplying data files with negative improvements and added errors, as described against the group response noted above.
Similarly, the possibility of the original non-grid connection continuing to be used could be clarified as a reflection of your organisation’s own knowledge of the electricity system. Simply not having data showing its use does not necessarily mean that it no longer is used. A transmission line that is not a part of the National Grid may well be of no interest to Transpower, and so data on its use may not be supplied by them.
Likewise, a power station not directly connected to the National Grid may leave Transpower uninterested in its operation so that they will not initiate a supply of data for it to you – as for Hau Nui, and others too. I have been concentrating on past operation that has been missed rather than ongoing operation that is being missed. Such power stations do exist and their generation does affect the state of the public supply, even if only to offset load that would otherwise be supplied from the National Grid - and to noticeable effect at places such as Linton. Persons such as Bryan Leyland have suggested that the cumulative effect of unaccounted-for generation may be part of the reason for the slow growth in apparent nett load.
If the Electricity authority is to monitor the operation of the electricity system comprehensively, it needs to gather comprehensive data, and not just that which happens to be offered to it by one participant such as Transpower. This means improving the way you collect data.

Yours faithfully,
Nicky McLean