As I stoke the boilers here at Beyond this Brief Anomaly after another (much) longer-than-anticipated intermission, it’s worth checking in on what this project has been all about to date. In a nutshell: I’ve attempted to make some modest in-roads into improving how we make sense of energy-related concepts, given the central role that I see for these in coordinating social action as we seek ways of living well together in the face of the increasingly urgent socio-ecological dilemmas confronting humanity. And in doing this, I’m drawing on principles from the field of inquiry known as systems thinking, or simply systems. If I were to try capturing what this means in essence, it would be along the lines of “considering the situations in which we’re interested as comprehensively as we’re able, by paying attention to their encompassing contexts.” The approach I’m taking extends this question of context to include considerations around cognition, language and meaning. Put simply, this implies treating the energy-related concepts that the inquiry deals with as sense-making “tools” and “artefacts” constructed by us. As such, they constitute important and influential parts of our shared culture. With them and through them, we bring our circumstances into being. What this implies is that the quality and coherence of our conceptual spaces “in here” affects the nature of our physical, social, economic, political etc. conditions “out there”. Attending to this “interior dimension” can have profound implications for the quality of the worlds that we bring about through the actions we engage in together. Continue reading
Category Archives: Efficiency
The economic view of systemic efficiency: energy return on energy investment
The last post looked at what I’ve called the engineering view of systemic efficiency, specifically the concept of available energy, or exergy. I refer to this as systemic because it considers energy conversion processes in relation to their specific operating contexts, in order to understand the useful work that a system can provide. While energy conversion processes serve an infinite array of human purposes, in the proximate or most immediate sense, we carry out energy conversions in order to do work—to effect transformations in our material worlds—and to provide heating (and while technically it’s not necessary to further differentiate it here, to provide illumination also). The systemic view provided by exergy analysis deals directly with the question of how much utility we can derive from an energy conversion process, and so it allows us to think about energy resources and infrastructure in a more concrete way than when we conduct analysis in terms of the nominal heating value of primary sources or fuels, in isolation from the particular situations in which they are used. Differences in energy use situations—different conversion technologies, implemented in different ways, operating in different physical environments—lead to differences in the utility that can be derived from an energy source. In establishing the efficiency of an energy conversion process—the useful energy output from the process divided by the nominal energy input—a focus on conversion systems and their parts (including the particular energy sources involved) only gets us so far. For a comprehensive view of efficiency we need to consider energy conversion processes in terms of all three levels of the basic systems hierarchy of system, sub-systems and supra-system. Exergy analysis provides the means for achieving this.
My reason for identifying this approach to thinking about efficiency as the engineering view relates in part to the scale at which exergy analysis’s systemic approach is most fruitfully applied—namely the plant or equipment scale. In other words, this is most immediately useful at the micro-economic or enterprise level, where we deal with technology components that make up economic units. In macro-economic terms, exergy analysis does have particular value for understanding performance of an economy’s energy sector, and also provides especially valuable insights in relation to transport and manufacturing activities. Coming to terms, though, with industrial societies—or, as we’ll see, any forms of social organisation for that matter—in physical- or energy-economic terms requires that we look beyond the enterprise and even sectorial levels. That is, we need a basis for thinking holistically about societies and their economic forms that relates energy supply and use at the overall macro-scale. It’s for this purpose that the concept of energy return on investment (EROI) (or energy return on energy investment—EROEI), has started, only relatively recently, to be better appreciated as so important. EROI tells us about the energy available for economic activity other than the supply of energy itself, and it is in this sense that I referred to it in the introductory post on efficiency as, roughly speaking, the economic equivalent of thermodynamic availability. Continue reading