Complex systems thinking and renewable energy systems

This chapter is divided into three parts. Part 1 deals with theoretical issues reflecting systemic problems in energy analysis: (i) when dealing with complex dissipative systems no quantitative assessment of output/input energy ratio can be substantive; (ii) metabolic systems define on their own, what should be considered as useful work, converters, energy carriers, and primary energy sources; (iii) the well known trade-off between power (the pace of the throughput) and efficiency (the value of the output/input ratio). This makes it impossible to use just one number (an output/input ratio) for the analysis of complex metabolic systems. Part 2 introduces basic concepts related to Bioeconomics: (i) the rationale associated with the concept of EROI; (ii) the conceptual definition of a minimum threshold of energy throughput, determined by a combination of biophysical and socio-economic constraints. These two points entail that the energy sector of developed countries must be able to generate a huge net supply of energy carriers per hour of work and per ha of colonized land. Part 3 uses an integrated system of accounting (MuSIASEM approach) to check the viability of agro-biofuels. The heart transplant metaphor is proposed to check the feasibility and desirability of alternative energy sources using benchmark values: (i) what is expected according to societal characteristics; and (ii) what is supplied according to the energy system used to supply energy carriers. Finally, a section of conclusions tries to explain the widespread hoax of agro-biofuels in developed countries. © 2008 Springer Science+Business Media B.V.