The author gave an update at the bottom of the article: Sunday update: Russ from Open Infrastructure Map has knocked up some code which generates a precise map of Greater London's pylons. Thanks Russ!

Link to Russ' update https://overpass-turbo.eu/s/1mYa

For anyone with time to spare, overpass-turbo is a great way to find/learn/do all kinds of things map-related.