Passage: Queen Mary 2 was intended for routine crossings of the Atlantic Ocean, and was therefore designed differently from many other passenger ships. The liner's final cost was approximately $300,000 US per berth. Expenses were increased by the high quality of materials, and having been designed as an ocean liner, she required 40% more steel than a standard cruise ship. Queen Mary 2 has a maximum speed of just over 30 knots (56 km/h; 35 mph) and a cruising speed of 26 knots (48 km/h; 30 mph), much faster than a contemporary cruise ship. Instead of the diesel-electric configuration found on many ships, Queen Mary 2 uses integrated electric propulsion to achieve her top speed. Diesel engines, augmented by gas turbines, are used to generate electricity for electric motors for propulsion and for on-board use.

Question: What is used to create energy for the electric motor?
Diesel engines