Anglesey Aluminium Metal Ltd, which shut down on 30 September 2009, was a joint venture between the Rio Tinto Group and Kaiser Aluminum. Its aluminium smelter, located on the outskirts of Holyhead, was one of the largest employers in North Wales, with 540 staff members, and began to produce aluminium in 1971. Until recently it produced up to 142,000 tonnes of aluminium every year and was the biggest single user of electricity (255 MW) in the United Kingdom.