I tried reading the programme, but it was endless scrolling on a phone. If they still open it up, I strongly recommend the underground power substation up near Parliament.
It was down an alley off Bourke St, you'd never know it was there any other day. It's one of the first power stations in the world, and it did DC power (not AC). But, the thing that blew my mind is that it had customers buying DC power in the 21st century!!
Amazing place, super interesting stories and the mercury AC/DC converter thing is beautiful.