# Energy conversion in isothermal nonlinear irreversible processes - struggling for higher efficiency

## TL;DR

This paper explores the dynamics and efficiency of energy conversion processes in nonlinear irreversible systems, including chemical, electrical, ecological models, and devices like fuel cells, highlighting optimal load conditions for maximum efficiency.

## Contribution

It provides analytical insights into the efficiency behavior of simple models of energy conversion, revealing conditions for optimal performance and efficiency limits.

## Key findings

- Efficiency peaks above 50% at optimal load
- Efficiency drops abruptly beyond maximal load
- Analytical models illustrate energy conversion dynamics

## Abstract

First we discuss some early work of Ulrike Feudel on structure formation in nonlinear reactions including ions and the efficiency of the conversion of chemical into electrical energy. Then we give some survey about energy conversion from chemical to higher forms of energy like mechanical, electrical and ecological energy. We consider examples of energy conversion in several natural processes and in some devices like fuel cells. Further, as an example, we study analytically the dynamics and efficiency of a simple "active circuit" converting chemical into electrical energy and driving currents which is roughly modeling fuel cells. Finally we investigate an analogous ecological system of Lotka - Volterra type consisting of an "active species" consuming some passive "chemical food". We show analytically for both these models that the efficiency increases with the load, reaches values higher then 50 percent in a narrow regime of optimal load and goes beyond some maximal load abrupt to zero.