multiple effect plate (MEP) distillation technology. The plants' energy is supplied primarily by steam and cooling water from the ship's gas turbines and diesel engines, or if needed by steam from the ship's two oil-fired boilers. The traditional multiple-effect distillation technology has been improved for the ship's plant, so that scaling of plates is reduced, vastly reducing maintenance required. The desalinated water has a very low salt content of less than five parts per million. Average total water production is per day with a capacity of so that there is ample spare capacity. The ship could easily be supplied by only two of the three plants. Potable water tanks have a capacity of , enough for more than three days of supply. If the engines are running on low load (when the ship is running at a slow speed) the engine jacket cooling water temperature is insufficient to heat the seawater to run the desalination plants. In that case steam from oil-fired boilers is used to heat the sea water. This is uneconomical as generating steam is expensive. It may be cheaper, therefore, to buy water in a particular port than to produce it on board. The seawater intakes are located in the hull of the ship. Concentrated salt solution (brine) is discharged to the sea closer to the ship's stern together with cooling water from the engines. An additional plant was added during the 2016 refit. Service history On 12 January 2004 Queen Mary 2 set sail on her maiden voyage from Southampton, England, to Fort Lauderdale, Florida, in the United States, carrying 2,620 passengers. She was under the command of captain Ronald Warwick, who had previously commanded Queen Elizabeth 2. Warwick is the son of William (Bill) Warwick, who had also been a senior Cunard officer and the first captain of Queen Elizabeth 2. The ship returned to Southampton late from her maiden voyage after bow doors covering the thrusters failed to shut in Portugal. During the 2004 Summer Olympics Queen Mary 2 sailed to Athens and docked at Piraeus for two weeks for use as a floating hotel, serving the then Prime Minister of the United Kingdom Tony Blair and his wife Cherie, French President Jacques Chirac, then United States President George W. Bush, and the United States Olympic men's basketball team. According to Cunard, Queen Mary 2s passengers have also included jazz musician Dave Brubeck and