Energy Efficiency: What it is, Why it is Important and How to Assess it

Details

Faced with increasing production costs and prices of industrial energies such as crude oil, of which market price has risen from roughly $10 per barrel in 1998 and about $20 per barrel at the start of 2000s to the current cost of about $100 per barrel, our one important means of action is bettering the energy efficiency of industry processes. This is nothing new as shown in all the engineering and fundamental work done to reduce the coal consumption of steam engines in the early industrial revolution.

The book deals with this large topic first by defining exactly the energy efficiency of a system. Even if its boundary and flows are well-defined, the value(s) of its efficiency depends on the indicator choice. For example, the typical agro-ethanol factory in Brazil is the most or least efficient relative to American ones, depending on the definition of the indicator.

Because the modern economy and population have thrived owing to cheap and abundant useful energy (and products derived from them like ammonia), efficiency of processes is important, even vital, to maintain these flows. However, it may encounter some fundamental limitations. It is also crucial to convert large natural resource into these useful flows.

The book suggests a methodology to assess the efficiency at a system level from the data, flows and established knowledge, found at the process level. This analysis determines the dependence of the system efficiency on the physical characteristics of its processes. It permits the avoidance of large errors and fixes the range of actions for improvement.

Finally, the book deals with energy conservation and its consequences. Historic exploitation of underground coal could not run its steam engine operation which requires more coal than it can lift. Can the agro-ethanol industry operate without external energies, i.e. it is more than self-reliant? (Imprint: Nova)