Evolution of energy systems: Patterns and mechanisms

Clarifying the evolution mechanisms of energy systems is related to our understanding of the essence of energy systems, which belongs to the category of epistemology. We use the principle of ecological complexity to expound on the synergies between energy systems and ecosystems and energy systems and complex systems, respectively, summarize the evolution pattern of energy systems, and propose the evolution mechanisms of energy systems from the micro to macro level. We argue that energy systems are driven by both momentum force and random walk force at the micro level, which makes the evolution of energy systems full of uncertainty in the definite trend. At the meso level, energy systems meet four conditions to form a self-organization structure: enough openness, far from equilibrium, small fluctuation, and nonlinear interaction. Therefore, the evolution at this level follows the law of self-organization evolution. At the macro level, the three agents of energy systems, households, firms, and governments, under the constraints of the ecosystem and technology, pursue the continuous improvement of efficiency as the common goal or compete or cooperate to enable mutual benefits and coexistence, and jointly promote the evolution of energy systems.