Envisioned as organized matter, any living system necessarily exists in a dissipative non-equilibrium state. Otherwise it would reduce to immutably stable combinatorial mixtures of chemical compounds. Indeed, whatever the adopted theoretical perspective on the origins of Life, energy has been much in demand to achieve free energy-consuming processes encountered in living systems such as, for instance, concentration of diluted matter, activation of stable building blocks towards subsequent chemical reactions, biochemical oscillations, active metabolic regulation, hypersensitivity for biological control, kinetic proofreading to overcome the thermodynamic limits during replication, or oriented molecular motion.
In fact, Earth has been (and is still) rich of energy: its solid crust is not chemically equilibrated with its fluid (liquid and gaseous) envelopes so as to generate primary sources of chemical energy, radioactivity has generated heat transfer from the depth to the surface of the planet, and Earth surface has been submitted to illumination from the Sun. The existence of abundant sources of energy was a prerequisite to make possible the emergence of Life envisioned as a dissipative chemical process. However, this thermodynamic constraint alone did not guarantee that sets of chemical reactions could extract from these sources the energy to emerge, reproduce, and evolve; an up-conversion chemical technology coupling primary energy sources to the sets of chemical reactions and involving much kinetic constraints had to be found.
In this lecture, I will introduce a simple and generic coupling strategy to propagate energy throughout chemical networks. It exploits spatial gradients of intensive thermodynamic parameters such as temperature, chemical potential, or affinity to activate and sustain futile cycles of reaction-diffusion bearing analogies with protometabolisms. Such situations are precisely encountered in deep-sea hydrothermal systems in which mixing between seawater and hydrothermal fluids generates steady-state gradients of temperature, pH, and redox potential.

References
1. M. Emond, T. Le Saux, J.-F. Allemand, P. Pelupessy, R. Plasson, L. Jullien, Energy propagation throughout a protometabolism leading to the local emergence of singular stationary concentration profiles, Chem. Eur. J., 2012, 18, 14375 - 14383.
2. T. Le Saux, R. Plasson, L. Jullien, Energy propagation throughout chemical networks, Chem. Commun., 2014, 50, 6189 - 6195.