1. Now pair it with a reversed Carnot engine as shown by the figure. 2. Fuel cells, for instance, can theoretically reach much higher efficiencies than a Carnot engine . 3. A Carnot engine operated in this way is the most efficient possible heat engine using those two temperatures. 4. See Carnot engine for the formula, which is indeed based on a ratio of temperatures in kelvins. 5. The figure at right shows a block diagram of a generic heat engine, such as the Carnot engine . 6. The paper outlined the basic energetic relations between the Carnot engine , the Carnot cycle, and motive power. 7. Else I could simply surround the heat source usually used in my Carnot engine with a vacuum and solar cells. 8. For the Carnot engine , the entire process is'reversible', and Equation ( 7 ) is an equality. 9. The Carnot engine is an idealized device of special interest to engineers who are concerned with the efficiency of heat engines. 10. The available work from a Carnot engine is at its maximum when the surroundings are at a temperature of absolute zero.