Collective working regimes for coupled heat engines.

Arrays of coupled heat engines are proposed as a paradigmatic model to study the trade-off between individual and collective behavior in linear irreversible thermodynamics. The analysis reveals the existence of a control parameter which selects different operation regimes of the whole array. In particular, the regimes of maximum efficiency and maximum power are considered, giving for the latter a general derivation of the Curzon-Ahlborn efficiency which surprisingly does not depend on whether or not the individual engines in the array work at maximum power.