The Creation of Wind Energy

When one side of a planet is irradiated by the sun, the other side is not and a temperature difference is created. With the planet s atmosphere as the working fluid operating between the planet s two extreme temperatures, macroscopic cycles can be performed that act as the origin of winds. Gordon and Zarmi [6] have generated the first model for this wind creation, which was subsequently refined by De Vos and Flater [7]. Both models and their outcome will be briefly discussed in this section. 

The sunny side of the planet is assumed to be a heat reservoir at temperature T3, the dark side is a reservoir at temperature T4. The illuminated side is receiving energy from the sun, but is also emitting energy. The dark side is emitting energy only. The net heat flow rate in sustaining the heat reservoir at T3 is 

Of particular interest is QabSOrbed/ the total amount of solar energy absorbed by the planet per unit time  

At the cold side, with temperature T4, the planet emits energy with a rate 

The Carnot engine operating between these temperatures T3 and T4 with heat absorbed at a rate Qin and rejected at a rate Qout will have an efficiency 

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After the introduction, we will briefly discuss the main characteristics of solar radiation. Consistent with the scientific principles on which this book is founded, a rigorous thermodynamic analysis will then follow of the creation of wind energy, of photothermal and photovoltaic energy conversion, and of photosynthesis. Most of this chapter has been based on the monograph Thermodynamics of Solar Energy Conversion by De Vos [1]. 

This section has discussed the creation of wind energy from solar radiation and has established that at maximum power (see Chapter 5) its efficiency is limited to some 6%-8%. In particular, we are of course equally, and perhaps even more, interested in the fraction of this energy that can be captured as electricity in a windmill park. 

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