Infralec

Infralec was the electricity distribution business owned by Hyder. Infralec was established in February 2000 to operate the electricity distribution network previously operated under the SWALEC brand before Swalec was sold to British Energy.

In 2001 Hyder was purchased by Western Power Distribution who sold off most parts of the organisation but kept Infralec which was rebranded as WPD South Wales.

...
Wikipedia