Fascinating building may be a key to the electrical grid storage/capacity mystery.
https://en.wikipedia.org/wiki/33_Thomas_Street?wprov=sfla1
Via WWI – WWII, the Nuke Hoax, the Cold War and JFK • Re: The Electricity supply. http://www.cluesforum.info/viewtopic.php?t=1950&p=2405482#p2405482
Don’t know if Scud checks in here – he called out the sinister substation building at Tottenham,London in a previous post
There’s a little about it here
https://infrastructure.planninginspectorate.gov.uk/wp-content/ipc/uploads/projects/EN020009/EN020009-000123-110823_EN020009_780469_Applicant%20Scoping%20Report.pdf
It certainly looks nothing like the Hackney substation on the same stretch of power lines.