Chapter 5
EXERGY IN POLICY DEVELOPMENT AND EDUCATION
EXERGY IN POLICY DEVELOPMENT AND EDUCATION
5.1. Introduction
It is important for the public to have a basic understanding, appreciation and awareness of many technical issues. Such
understanding and awareness fosters healthy public debate about problems and possible solutions, often helps guide how
public funds are spent and facilitates policy development.Energy issues are no exception. Yet, the public's understanding of energy issues is often confused. In large part, this
situation is attributable to the public having next to no understanding of exergy. It is explained why such an understanding
is necessary in this chapter.It is easier for the public to be educated about and aware of exergy if students are adequately educated about exergy
in appropriate venues (university and college thermodynamics courses, primary and secondary schools, etc.).Consequently, this chapter deals with education and awareness of exergy, first by focusing on the public and then by
dwelling on the education of thermodynamicists as well as other technical people. The objective is to demonstrate that
exergy has a place and role to play in policy development regarding energy-related education and awareness.Exergy can play a key role in developing appropriate and beneficial energy-related policies relating to education and
awareness. Two main areas where exergy can have an impact on policies are discussed in this chapter: public education
and awareness and student education. The former is more general, but is supported by the latter. Regarding public
education and awareness about exergy, it appears that the public is often confused when it discusses energy, and needs to
be better educated about exergy if energy issues and problems are to be addressed appropriately. Regarding the education
of students about exergy, it appears that the coverage of exergy in thermodynamics education is often insufficient and
inappropriate. Better coverage of exergy is needed to improve thermodynamics education and to make it more interesting
to students, and a basic level of 'exergy literacy' is needed among engineers and scientists – particularly those involved
in decision making.
5.2. Exergy methods for analysis and design
Some features of exergy follow:| • | When energy quality decreases, exergy is destroyed. Exergy is the 'part' of energy that is useful to society and has economic value and is thus worth managing carefully. |
| • | A system has no exergy when it is in complete equilibrium with its environment. Then, no differences appear between the system and the environment in temperature, pressure or constituent concentrations. |
| • | The exergy of a system increases as the deviation of its state from that of the environment increases. For instance, hot water has a higher exergy content in winter than on a hot summer day, while a block of ice contains little exergy in winter but a significant quantity in summer. |
| • | Consider an adiabatic system containing fuel and air at ambient conditions. The fuel and air react to form a mixture of hot combustion gases. During the combustion process, the energy in the system remains fixed because it is adiabatic. But the exergy content declines as combustion proceeds due to the irreversibilities associated with the conversion of the high-quality energy of fuel to the lower-quality energy of combustion gases. The different behaviors of energy and exergy during this process are illustrated qualitatively in Fig. 5.1. |
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Questia, a part of Gale, Cengage Learning. www.questia.com
Publication information:
Book title: Exergy: Energy, Environment, and Sustainable Development.
Contributors: Ibrahim Dincer - Author, Marc A. Rosen - Author.
Publisher: Elsevier.
Place of publication: Boston.
Publication year: 2007.
Page number: 68.
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