3.7: Entropy and Quality of Energy

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The following video shows energy conversions that occur in a power plant.

The following video shows a demonstration of a small-scale power plant.

The following video quantitatively shows the basic energy conversions in the three main components of a power plant.

Figure 3.7.1 shows two temperature scales. The scale labeled "HOT," shows the range of temperatures for the combustion of gases in a power plant. The scale, "COLD," shows the range of temperatures at which gases are exhausted from the power plant.

Figure 3.7.1. Power plant temperatures. Red indicates power plant combustion temperatures while blue indicates exhausted gas temperatures.

Table 3.7.1 shows the power plant efficiencies at varying temperatures.

Table 3.7.1. Power plant efficiencies (in %) as a function of the hot and cold temperatures

	Hot 350°C	Hot 400°C	Hot 500°C	Hot 600°C	Hot 700°C	Hot 800°C	Hot 900°C	Hot 1000°C
Cold 300°C	8	15	26	34	41	47	51	55
Cold 250°C	16	22	32	40	46	51	55	59
Cold 200°C	24	30	39	46	51	56	60	63
Cold 150°C	32	37	45	52	57	61	64	67
Cold 100°C	40	45	52	57	62	65	68	71