An Exact Model of the Power/Efficiency Trade-Off While Approaching the Carnot Limit

Understand

The Carnot heat engine sets an upper bound on the efficiency of a heat engine.

• As an ideal, reversible engine, a single cycle must be performed in infinite time, and so the Carnot engine has zero power.
• However, there is nothing in principle forbidding the existence of a heat engine whose efficiency approaches that of Carnot while maintaining finite power.
• Such an engine must have very special properties, some of which have been discussed in the literature, in various limits.