Certainly: read https://wiki.openstreetmap.org/wiki/Relations_are_not_categories
Also read the discussion with you from 2 months ago at https://www.openstreetmap.org/changeset/171884705
This relation, as created by you (and the next 60 versions modified by you) is about 0% complete of the coverage of the UK its name proposes.  How many more versions are required to complete it and maintain it?  Noone else is going to waste their time helping with this.
You can get all the substations in any required geographical area with an Overpass Turbo query, filter at will on voltage, operator etc according to the tags available, and it is automatically completely up to date with everyone in the OSM community helping.