3.2 The Concept of Energy
41
Figure 3.1 Development of the global primary energy consumption to 2008 and three
GEA pathways (“GEA explored 60 alternative pathways of energy transformations toward
a sustainable future that simultaneously satisfy all its normative social and environmental
goals of continued economic development, universal access to modern energy carriers, climate and environment protection, improved human health, and higher energy security (see
Section TS-2.6). The pathways were divided into three different groups, called GEA-Supply,
GEA-Mix, and GEA-Efficiency, representing three alternative evolutions of the energy system toward sustainable futures. The pathways within each group portray multiple sensitivity
analyses about the ‘robustness’ of the three different approaches in mastering the transformational changes needed to reach more sustainable futures.” [Je2012, p. 71].) to 2030 and 2050
[Jo+2012, p. 9]
3.2
The Concept of Energy
3.2.1 Work, Energy and Power
“Energy is one of the most basic scientific concepts and is a unifying principle that
has applications in all scientific disciplines” [My2006, p. 68]. Various forms of
energy exist, generally they are classified according to their source, e.g., nuclear,
chemical, solar, geothermal or electrical energy. Energy can be stored within a
system in three general forms the inner energy, the potential energy and the kinetic
energy. While potential energy is the stored energy, resulting from the position of
a system of objects that exert forces on one another, kinetic energy is understood
as the energy of motion [My2006, pp. 68–69; MVG2010, pp. 28–29]. When a
system changes its energetic state from one to another, this transition is described
41
Figure 3.1 Development of the global primary energy consumption to 2008 and three
GEA pathways (“GEA explored 60 alternative pathways of energy transformations toward
a sustainable future that simultaneously satisfy all its normative social and environmental
goals of continued economic development, universal access to modern energy carriers, climate and environment protection, improved human health, and higher energy security (see
Section TS-2.6). The pathways were divided into three different groups, called GEA-Supply,
GEA-Mix, and GEA-Efficiency, representing three alternative evolutions of the energy system toward sustainable futures. The pathways within each group portray multiple sensitivity
analyses about the ‘robustness’ of the three different approaches in mastering the transformational changes needed to reach more sustainable futures.” [Je2012, p. 71].) to 2030 and 2050
[Jo+2012, p. 9]
3.2
The Concept of Energy
3.2.1 Work, Energy and Power
“Energy is one of the most basic scientific concepts and is a unifying principle that
has applications in all scientific disciplines” [My2006, p. 68]. Various forms of
energy exist, generally they are classified according to their source, e.g., nuclear,
chemical, solar, geothermal or electrical energy. Energy can be stored within a
system in three general forms the inner energy, the potential energy and the kinetic
energy. While potential energy is the stored energy, resulting from the position of
a system of objects that exert forces on one another, kinetic energy is understood
as the energy of motion [My2006, pp. 68–69; MVG2010, pp. 28–29]. When a
system changes its energetic state from one to another, this transition is described