How much wind energy does the atmosphere generate, and how much of it can at best be used as renewable energy? This review aims to give physically-based answers to both questions, providing first-order estimates and sensitivities that are consistent with those obtained from numerical simulation models. The first part describes how thermodynamics determines how much wind energy the atmosphere is physically capable of generating at large scales from the solar radiative forcing. The work done to generate and maintain large-scale atmospheric motion can be seen as the consequence of an atmospheric heat engine, which is driven by the difference in solar radiative heating between the tropics and the poles. The resulting motion transports heat, which depletes this differential solar heating and the associated, large-scale temperature difference, which drives this energy conversion in the first place. This interaction between the thermodynamic driver (temperature difference) and the resulting dynamics (heat transport) is critical for determining the maximum power that can be generated. It leads to a maximum in the global mean generation rate of kinetic energy of about 1.7 W m−2 and matches rates inferred from observations of about 2.1–2.5 W m−2 very well. This represents less than 1 % of the total absorbed solar radiation that is converted into kinetic energy. Although it would seem that the atmosphere is extremely inefficient in generating motion, thermodynamics shows that the atmosphere works as hard as it can to generate the energy contained in the winds. The second part focuses on the limits of converting the kinetic energy of the atmosphere into renewable energy. Considering the momentum balance of the lower atmosphere shows that at large-scales, only a fraction of about 26 % of the kinetic energy can at most be converted to renewable energy, consistent with insights from climate model simulations. This yields a typical resource potential in the order of 0.5 W m−2 per surface area in the global mean. The apparent discrepancy with much higher yields of single wind turbines and small wind farms can be explained by the spatial scale of about 100 km at which kinetic energy near the surface is being dissipated and replenished. I close with a discussion of how these insights are compatible to established meteorological concepts, inform practical applications for wind resource estimations, and, more generally, how such physical concepts, particularly limits regarding energy conversion, can set the basis for doing climate science in a simple, analytical, and transparent way.

中文翻译：

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大气中风能的物理极限及其作为可再生能源的用途：从理论基础到实际意义

大气产生多少风能，其中多少最多可以用作可再生能源？本综述旨在为这两个问题提供基于物理的答案，提供与从数值模拟模型中获得的那些一致的一阶估计和灵敏度。第一部分描述了热力学如何确定大气在物理上能够从太阳辐射强迫中大规模产生多少风能。为产生和维持大规模大气运动所做的工作可以看作是大气热机的结果，这是由热带和极地之间的太阳辐射加热差异驱动的。由此产生的运动会传输热量，这会消耗这种不同的太阳能加热和相关的大规模温差，这首先推动了这种能量转换。热力学驱动因素（温差）和由此产生的动力学（热传输）之间的这种相互作用对于确定可以产生的最大功率至关重要。它导致全球平均动能产生率的最大值约为 1.7 W m-2，并且与从大约 2.1-2.5 W m-2 的观测推断出的速率非常匹配。这代表了转化为动能的总吸收太阳辐射的不到 1%。尽管大气似乎在产生运动方面效率极低，但热力学表明，大气尽可能努力地产生风中包含的能量。第二部分侧重于将大气动能转化为可再生能源的局限性。考虑到低层大气的动量平衡表明，在大尺度上，最多只有大约 26% 的动能的一小部分可以转化为可再生能源，这与气候模型模拟的见解一致。这产生了一个典型的资源潜力，在全球平均每表面积 0.5 W m-2 的数量级。单台风电机组和小型风电场的显着差异可以用大约 100 公里的空间尺度来解释，在该空间尺度上，地表附近的动能正在消散和补充。我最后讨论了这些见解如何与既定的气象概念兼容，为风力资源估计的实际应用提供信息，以及更一般地说，这些物理概念，特别是关于能量转换的限制，