I think the CEGB called it South Denes Power Station and not Great Yarmouth Power Station.

Paul Godfrey is correct. I worked at S Denes P S from 1957 to 1974.
Great Yarmouth Power Station was an old small station about a quarter of a mile further North. The switchgear at the old site was still used for local distribution and the site for the connection to the grid system was on the other side of the road.

Can't believe they took this building down!

It is possible that these photographs were taken by Ford Jenkins of Lowestoft or one of his assistants. Ford took many photographs for the CEGB including the construction of Sizewell A.